Investigating and Litigating Paintball and Airsoft Injury Cases

Copyright and disclaimer

Copyright Steve Wolf. All rights reserved. No part of this book may be reproduced or distributed without written permission.

Nothing here is legal advice, medical advice, or a substitute for retained counsel or a treating physician. Standards, statutes, and case law change, and they differ by state. Verify every authority against the current text before you rely on it.

Introduction: The Gun That Was Not Empty

A five year old boy stood in a church back yard in Forresthill, California in July of 2007, watching teenagers play paintball. The owner of the gun beside him had unscrewed the air bottle and pulled off the barrel, because he believed that made the gun safe. The gun fired.

Nathan Earnst lost his eye. He was five, he was not playing, and nobody had asked him to accept any risk. The shot came at point blank range from a gun that three teenagers and every adult on that property would have sworn was empty. It was not empty. Blowback and stacked tube guns hold enough gas downstream of the valve to fire one to three more shots after the bottle comes off. The manual said so on page two. Nobody at that church had opened the manual.

A paintball gun is not a toy. It throws a .68 caliber ball at up to 350 feet per second, over two hundred miles per hour, and the ball is wider than the bone opening that would otherwise shield the eye. That is why fields cap velocity at 280 to 300 feet per second. Forresthill had no cap, no chronograph, no barrel covers, no netting, no posted rules, and no adult who could name a single piece of the equipment. Seven controls exist to stop this injury. All seven were missing at once.

I own and operate a paintball park in Austin, Texas. I hold a Class 1 Federal Firearms License, I am a National Rifle Association and state certified firearms instructor and a certified instructor trainer, and I run a state licensed summer camp. I coordinate stunts and special effects, which is the business of letting dangerous things happen on purpose without anyone getting hurt. I have chronographed thousands of guns and I write the rules people play under at my own field. I have been retained as the plaintiff's expert in paintball eye loss cases.

Everything here is something I measured, something I testified to, or something I can point you to a primary source for. Where I cannot, I say so, and the item goes in the punch list at the back.

An Accident Waiting for a Victim

In July of 2007 a church in Forresthill, California let teenagers play paintball in the back yard. A five year old boy named Nathan Earnst, who was not playing, lost an eye to a point blank shot from a marker held by a thirteen year old. The owner of that marker had unscrewed the air bottle and pulled the barrel off, because he believed that made it safe. Every clause in that paragraph is a separate failure. I was the plaintiff's expert in Ernst v. Church, tried in Sacramento.

Why I opened with what I do for a living

The demonstrative video I built for that trial opens with credentials, because a jury deciding whether a backyard paintball game was safe needs to know in fifteen seconds who is telling them it was not.

My name is Steve Wolf, and I'm a professional stunt and special effects coordinator for movies and television shows. I've worked for every major studio on hundreds of projects. I blow things up, light people on fire, crash cars, and throw people off roofs. But I do it all using science and safety to make sure no one gets hurt. I'm also a licensed firearms instructor, and I own the largest paintball park in Austin, TX. My work always involves managing risk, and designing systems that allow dangerous activities to be done safely.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church, Sacramento, California

The script then states the rule the case hangs on.

Whether I'm working with stage combat, explosives or paintball guns, there are rules that must be followed in order to stay safe. Obey the rules, and everyone has fun. Ignore the rules, someone gets hurt or dies.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church

The marker is not a toy, and the box said so

A paintball gun is not a toy. It fires a .68 caliber sphere at up to about 350 feet per second out of the box, over two hundred miles per hour. That ball is roughly 17.27 millimeters across, wider than the human cornea and wider than the orbital opening that would let bone take the hit instead of the globe.

The marker shipped in a carton with a warning printed larger than the product name, which killed any argument that the danger was hidden. From the script: "guns like this are so dangerous, that some of them, like the one in the accident, come packaged with a warning on the box that is even bigger than the name of the product." And: "devices like this must always be used with trained adult supervision. It even says so right on the box." The manufacturer set the condition and the host did not meet it. Chapter 17 covers why an ignored box warning still matters, and why it does not clear the manufacturer either.

The gun that stays loaded after you unload it

Paintballs are pushed out of a gun by pressurized gas: compressed air, nitrogen, or carbon dioxide, stored in a bottle that screws into the back. Take the bottle off and almost every reasonable adult decides the gun is dead. For most designs that is close enough. For this one it was not.

Most paintball guns become harmless when the pressurized tank is taken off. But with this brand, enough gas is trapped inside the gun, even after the tank is removed, to fire 1 to 3 shots. When Mike Hendricks unscrewed the tank from his gun, and removed the barrel, I don't doubt he thought he'd made his gun safe. But it doesn't really matter what he thought. Obviously, his gun was still extremely dangerous.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church

Blowback and stacked tube designs hold a charged volume downstream of the valve after the bottle comes off, and that trapped charge cycles the valve one to three more times. Chapter 10 gives the engineering and states how thin the public documentation is.

That is a design failure and a warnings failure, and both belong to the manufacturer. The information that would have stopped it was two pages into the manual.

The apple, the egg, the orange, and the steel plate

Numbers do not move juries. Twelve and a half joules means nothing to a retired schoolteacher in seat four. So I lined up four objects at the distance Nathan stood from Hendricks and shot them on camera.

I've lined up a few items, all at about the same distance from this gun as Nathan was from Hendricks. An Apple. An Egg. An Orange. A steel plate. You can see and hear the destructive power. That's certainly what makes it enticing to young men, but also what makes it deadly, another reason that safety is so critical.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church

Each object carries a different piece of the physics.

The apple is a dense, water filled sphere with a tough skin. The paintball does not pass through. It dumps its energy into the surface and the shockwave splits the flesh underneath, which is how a blunt globe rupture works. The egg is a thin brittle shell around fluid under slight pressure, and so is an eye: cornea and sclera around vitreous. When the shell fails, the contents leave. Chapter 5 gives the published criterion, globe rupture above 17.21 megapascals of corneoscleral stress or 1.01 megapascals of vitreous pressure. The egg makes that visible.

The orange has a thick rind over segmented fluid filled tissue, and it shows energy getting through a protective layer and wrecking what is behind it while the outside still looks fine. An eye can be lost without a hole in it. The steel plate is there so the jury hears the impact. A paintball hitting steel at three hundred feet per second makes a sound nobody associates with a toy, and it kills the phrase "spitball gun" before defense counsel can say it. These are not spitball guns. They are deadly weapons.

Chapter 16 covers how to build this demonstration so it survives a challenge to admissibility.

Nobody was in charge, and the documents prove it

The speed of a paintball changes with the paint, the gas, and the temperature, enough that the same gun can be legal at nine in the morning and illegal at two in the afternoon. The fix is a chronograph and an Allen wrench, under a minute per gun. Nobody at Forresthill owned a chronograph.

Barrel covers catch the ball if the gun fires by accident. The cover goes on before the player leaves the field and comes off only after he is back inside the boundary with a bottle attached. At Forresthill the covers came off before the players left the playing area, and no one was responsible for enforcing otherwise.

The organizers of this event didn't provide active adult supervision. If anyone was in charge, they certainly didn't enforce safety rules. They let paintball guns be fired in an area where bystanders had no protection from the players. Anyone in the area could have been seriously injured. This arrangement was an accident waiting for a victim.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church

That last line is the theory of the case. The event did not have an accident. The event was an accident, running all afternoon, waiting for somebody to walk into it. If Nathan Earnst had not been standing there the next child would have been. A freak occurrence is bad luck. A condition this dangerous produces an injury on schedule.

The seven failures

This is the closing tally from the demonstrative, in the order I gave it to the jury.

1. No active adult supervision. Chapters 12 and 13.
2. No one knowledgeable about the equipment. Chapters 2 and 12.
3. No velocity control and no chronographing. Chapters 3 and 9.
4. Nothing separating players from spectators. Chapter 11.
5. A marker that is counter-intuitively dangerous, holding enough residual gas to fire one to three shots after the supply bottle is removed. Chapters 10 and 17.
6. No barrel blocking devices in place. Chapter 8.
7. Rules not posted, not observed, and not enforced. Chapters 6, 12, and 19.

Any one of those seven controls, working, stops this injury. An unsupervised event does not fail through one dramatic mistake. Everything that makes the activity survivable disappears at the same time.

How the case ends

The last line of the narration is aimed at the hosts, not the boy who pulled the trigger.

I'm all in favor of exciting sports, shooting, and even teenagers playing combat games, but if you don't show even the slightest concern for safety, for keeping kids from getting hurt, then you have no business hosting dangerous activities, and you owe Nathan Earnst a debt that you can never repay.

Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church

What a Paintball Gun Is

A paintball marker is a pneumatic launcher. It stores gas at high pressure, releases a measured slug behind a ball, and uses part of the same release to reset itself. Every argument in a paintball case comes back to that gas: how much, where it is stored, at what pressure, and where it still is after somebody thinks he removed it.

The parts, named once, in order

The four architectures, and why the difference matters legally

Nearly every marker falls into one of four families, and the family decides how much gas the marker holds after the bottle comes off. That is the difference between a dead object and a loaded one.

Blowback. A mainspring drives a hammer into the valve stem, opening the valve. Gas then goes two places at once: forward past the bolt to push the ball, and backward through a passage to shove the hammer back and recock it. Simple, cheap, and durable. This is also the family that holds a charged volume after the bottle is disconnected, because the passages and chambers between the valve and the bolt stay pressurized when the supply is cut.

Stacked tube. A layout, not a firing principle. The valve and hammer sit in a lower tube and the bolt in an upper tube, connected by a linkage. Most inexpensive semi automatic markers, including those sold in big box sporting goods stores, are stacked tube blowbacks. The stacked geometry adds internal volume, and volume is what stores the residual charge.

Spool valve. The bolt and valve are the same assembly, and pressure differentials across a sliding spool move the bolt back and forth. Spool designs are smoother and quieter and generally hold less residual pressure in a fireable configuration once supply is removed, though not none.

Electropneumatic. A circuit board reads the trigger as a switch and fires solenoid valves, which pilot the pneumatics. This family enables selectable fire modes: semi automatic, burst, and full automatic. The legal significance is rate of fire. One trigger pull on a burst setting can launch three balls, which is why the barrel plug failed as a device and why an accidental discharge is rarely a single event.

Table 2.1 Marker architectures compared

Follow the gas from bottle to muzzle

1. Gas leaves the supply bottle through the bottle valve, which opens when the bottle is screwed into the marker's adapter and closes when it is unscrewed far enough.
2. It enters the marker's gas passage through a threaded fitting called the air source adapter.
3. It reaches the regulator, which drops it to operating pressure. Carbon dioxide markers may have no true regulator, only an expansion chamber, which is why they swing so badly with temperature.
4. It fills the valve chamber, the reservoir the next shot comes from.
5. The trigger releases the hammer or energizes the solenoid, unseating the valve stem for a few milliseconds.
6. Gas exits the valve into the transfer passage, into the bolt, and out the front of the bolt behind the ball.
7. The ball accelerates down the barrel and the remaining gas vents at the muzzle behind it.
8. On a blowback, part of that same gas is diverted rearward through the power tube to push the hammer back against the mainspring, resetting the marker.

Now unscrew the bottle. Steps 1 and 2 stop and steps 3 through 8 still run. The gas in the regulator body, valve chamber, and transfer passages is still there, still at pressure, still on the firing side of the valve, and the hammer still has spring preload. Removing the bottle does not unload the marker. It stops resupplying it.

Hoppers, loaders, and why feed rate shows up in causation

A gravity hopper drops balls into the breech by weight alone and tops out around eight to ten balls per second, less if the player is moving or the hopper is tilted. An electronic loader uses a motor and sustains far higher rates. A marker capable of twelve rounds per second but fed at six will chop balls in the breech, which is both an evidence signature and a source of velocity variation. And when a witness describes "a burst," the loader determines whether that was possible with the equipment in evidence.

The safety, and why it does almost nothing

Most markers carry a push button mechanical safety that blocks the trigger or the sear. It is not a decocking device, it does not vent stored gas, and on many designs an impact that jars the sear defeats it. That is why American Society for Testing and Materials standard F2272 requires markers to resist accidental discharge from specified jolts. A safety that blocks a trigger does not address a marker that discharges when dropped, and neither addresses a marker that still holds a charge after the bottle is off.

What to write down when you first hold the marker

Record all of this before anything comes apart: make, model, and any serial or lot marking; fire mode position; whether a bottle is attached and what its gauge reads; whether a barrel blocking device is attached; whether the hopper holds paint and how much; whether the safety is on; the velocity adjuster position in turns from bottom; and broken paint in the breech or barrel. Every one disappears the first time somebody helpfully cleans the gun. Chapter 15 turns this into a full evidence protocol.

Speed, Energy, and the Field Limit

A paintball is a soft sphere of gelatin around a fill of dye and thickener, heavy for a sporting projectile and slow for a firearm projectile, which makes it survivable to a torso and dangerous to an eye. Every figure below is marked as published or as my own calculation.

Caliber, mass, and what a paintball weighs

A .68 caliber paintball is not a precision object. Diameter varies with manufacturing run, storage humidity, and age; moisture swells a ball and drying shrinks it. Typical field paint runs near three grams, and I use 3.0 grams for calculation and tell juries it is a working figure. A ball that weighs 2.8 grams on one lot and 3.3 on another does not carry the same energy at the same speed.

The 280 to 300 feet per second field limit and where it came from

Commercial fields cap muzzle velocity between 280 and 300 feet per second. Small indoor fields go as low as 250, because engagement distances are shorter and there is no room to bleed energy. Germany caps energy rather than velocity, at 7.5 joules.

That limit is not a line below which an eye is safe. It is the speed a paintball mask lens is built and tested to stop. Manufacturers design lenses to hold against paintballs traveling up to 90 meters per second, which is 300 feet per second. The field limit keeps the ball inside what the mask can take, and does nothing else. Take the mask off and the 300 foot per second limit protects nobody.

The energy arithmetic, and which parts of it are mine

Kinetic energy is one half the mass times the velocity squared. Because the velocity term is squared, a twenty percent velocity increase produces a forty four percent energy increase, which is why a marker that drifts high on a hot afternoon matters.

Table 3.1 Paintball kinetic energy at a mass of 3.0 grams. All values are the author's own calculation from one half m v squared, not published figures. Verify against your own chronograph and your own paint.

Momentum matters as much as energy for blunt ocular trauma, and it is the quantity that gets left out. Momentum is mass times velocity, so a 3.0 gram ball at 91.4 meters per second carries 0.274 kilogram meters per second while a 0.20 gram airsoft pellet at 106.7 meters per second carries 0.021, about thirteen times less. The defense will point out that the pellet is faster, which is true and does not help them. The heavier ball delivers far more impulse to the globe, over a longer contact time, and that is the loading condition the ocular injury literature models.

Carbon dioxide swings with temperature and compressed air does not

The Wikipedia entry on paintball markers states the mechanism plainly: "The CO2 liquid must vaporize into a gas before it can be used. This causes problems such as inconsistent velocity. Cold weather can cause problems with this system, reducing the vapour pressure and increasing the chance for liquefied gas to be drawn into the marker."

Two failure modes follow. In cold weather vapor pressure drops and velocity drops with it, which sounds harmless until the player compensates by cranking the velocity adjuster. In hot weather vapor pressure rises steeply and so does velocity, on a marker set in the morning and never rechecked. Rapid firing also chills the bottle by evaporative cooling, so velocity sags across a string and recovers as the bottle warms. A single reading from a cold or hot bottle is not representative of anything.

Liquid carbon dioxide drawn into the marker is a separate hazard. It expands violently in the valve and produces a velocity spike well above what the marker was set to, along with mechanical damage to seals. That is why anti siphon tubes and expansion chambers exist.

Bore to paint match, the variable nobody logs

The barrel's internal diameter must match the diameter of the paint being fired. The equipment literature is direct about it: "The bore must properly match the type of paint being fired, the most critical aspect of a barrel. A mismatched selection will result in velocity variations."

Paint undersized for the bore lets gas blow past the ball, lowering velocity and scattering it shot to shot. Oversized paint binds, raises pressure behind the ball, and can raise velocity or break the ball inside the barrel. Serious players carry barrel inserts in several bore sizes and select for the day's paint. Nobody at a backyard event does this or records what paint was in the hopper. When you reconstruct a shot, the paint lot and the barrel bore help determine whether your test result is admissible as substantially similar.

Paint fill, shell brittleness, and humidity

The shell is gelatin, and gelatin is hygroscopic, meaning it absorbs water from the air. Paint stored in a humid garage swells and softens. Paint stored in a dry, hot car grows brittle.

A soft, swollen ball deforms in the breech, chops on the bolt, and flies erratically. A brittle ball breaks on the bolt or in the barrel, coating the bore and destroying the next several shots. Brittleness also changes what happens at the target: a brittle shell fragments and spreads its energy over a wider area, while a tough shell holds together and behaves more like a solid projectile, which is worse for an eye. Field operators rotate paint stock and store it in climate controlled space. A church garage in July is not climate controlled space.

Table 3.2 Variables that change paintball velocity on the same marker with the same setting

When a defendant says the gun was fine, ask which of those nine variables he measured.

Airsoft Is Not a Smaller Paintball

Airsoft guns launch six millimeter plastic spheres. They look like firearms, they are marketed alongside paintball, and pleadings and police reports confuse the two constantly. Airsoft is a different machine throwing a different projectile at a different energy, under a different standard, regulated by a statute paintball is expressly exempt from. Getting this wrong in a report is the fastest way to be impeached.

Six millimeters, and weights that span a factor of four

Airsoft pellets come in 6, 6.4, and 8 millimeter diameters. Standard six millimeter pellets are manufactured to 5.95 millimeters plus or minus 0.01 millimeter, a tighter tolerance than paint has ever held.

Weights run from 0.12 to 0.48 grams, with the popular range 0.20 to 0.32 grams and long range shooters using 0.36 to 0.40 grams. The lightest pellets are inaccurate and lose speed fast, and they are what comes in the bag with a cheap gun, which makes them what a child will be shooting.

Velocity runs 60 to 125 meters per second, or 200 to 410 feet per second, and the practical ranges are set by game type rather than physics.

Table 4.1 Airsoft velocity conventions by game type

The elevenfold energy gap

A 0.20 gram pellet at 350 feet per second carries 1.138 joules, a published figure. The same pellet at 100 meters per second carries 1 joule, the round number most national regulations are written around.

A 3.0 gram paintball at 300 feet per second carries about 12.5 joules by my calculation, roughly eleven times the muzzle energy of a standard airsoft pellet. That ratio cuts both ways. It beats the plaintiff's expert who treats the two sports as the same thing, and the defense expert who argues that because several countries regulate airsoft at one joule, paintball at twelve and a half joules must be fine too.

Joule limits around the world, and why the United States has none

Most countries that regulate airsoft regulate energy rather than velocity, because energy does not change when a player switches pellet weight.

Table 4.2 National airsoft energy limits

Every jurisdiction that regulates at all regulates full automatic fire more tightly than single shots, because volume of fire is its own hazard, separate from per shot energy. The United States sets no federal energy limit. The only federal statute touching airsoft is about what the gun looks like.

The orange tip statute, and the exemption people get wrong

The orange muzzle marking requirement is 15 United States Code section 5001, implemented at 15 Code of Federal Regulations Part 1150. The marking must be one quarter inch or longer and must cover the muzzle end.

That exemption leaves an open question. Airsoft guns also expel a projectile through the force of air pressure, so on the face of the text they arguably fall inside the same exclusion that covers paintball and pellet guns. The industry orange tips them anyway, and enforcement has long treated airsoft replicas as covered look alike firearms. I know of no authoritative resolution and I will not invent one. Whether section 5001 reaches airsoft belongs on your legal research list, not in your report as an assumption.

Section 5001 also preempts inconsistent state marking laws while leaving states free to bar sales to minors. A state cannot demand a different color of tip. It can bar the sale to a fourteen year old, and it can bar carrying the thing in public.

State restrictions on possession and public use

New Mexico, New York, and New Jersey prohibit public use of airsoft guns, and Chicago and Detroit impose city level restrictions. New York also reaches possession by age. New York Penal Law section 265.05 provides that "It shall be unlawful for any person under the age of sixteen to possess any air-gun, spring-gun or other instrument or weapon in which the propelling force is a spring or air." That reaches both airsoft guns and paintball markers, and violation results in adjudication as a juvenile delinquent. Chapter 18 develops it as a negligent entrustment predicate.

New York also regulates the appearance of the object, under General Business Law sections 871 and 872, and California Penal Code section 20170 bars open display of an imitation firearm in a public place. Chapter 18 quotes all three and works through what they reach.

The airsoft eye protection standard is F2879, and it is not F2999

The airsoft eye protection standard is American Society for Testing and Materials standard F2879, current edition F2879-22. F2999 is the consumer safety specification for adult jewelry. I have seen that transposition in a report, and it destroyed the witness.

F2879 covers devices for airsoft participants using six millimeter projectiles, intended to minimize or significantly reduce injury to the eye and adnexa from impact and penetration. It protects the eyes and immediate facial area only, not the whole face and head as the paintball standard does, and it draws an explicit line between competition shooting at backstops, where eyewear meeting American National Standards Institute standard Z87.1 may suffice, and tactical airsoft, where it does not. Chapter 6 uses that concession to prove Z87.1 is inadequate for player versus player impact in either sport.

What airsoft does to an eye

Lower energy does not mean safe. Kennedy, Ng, and Duma evaluated airsoft eye injury risk using parametric risk functions and found corneal abrasion risk near one hundred percent and hyphema risk above seventy five percent. Marshall, Dahlstrom, and Powley put the minimum velocity for eye penetration above 99 meters per second, or 325 feet per second, at an energy density of 4.3 to 4.8 joules per square centimeter for six millimeter airsoft. A designated marksman rifle at 450 feet per second and a bolt action at 500 both sit well above that.

Khalaily and colleagues followed twenty six airsoft eye injury patients for seven to ten years and found traumatic cataract in three cases, 11.5 percent, and iris dialysis in one case, 3.8 percent. Takahashi and colleagues modeled airsoft impact by finite element analysis and found that hyperopic eyes, meaning farsighted eyes with shorter axial length, deform most. That is the eggshell plaintiff rule, run through a computer model. Dockery and colleagues reported mean final visual acuity of 20/200 for airsoft injuries and 20/500 for paintball, the worst of every shooting sport studied.

The Eye and How It Fails

A paintball to the chest leaves a welt. The same paintball to the eye ends vision in that eye about half the time. The reason is geometry and materials, not bad luck, and once a jury understands that they stop seeing a freak result and start seeing what happens whenever an unprotected eye is put in front of a twelve joule projectile.

Why the orbit protects everything except the thing you need

The eye sits in a bony socket called the orbit. The orbital rim, the ridge you can feel around your eye, deflects large blunt objects. A baseball, a fist, or a hockey puck is wider than the orbital opening, so the rim takes much of the load and the globe is partly shielded.

A .68 caliber paintball is 17.27 millimeters across, well inside the adult orbital opening, and a six millimeter airsoft pellet is smaller still. Both load the globe directly, which is why paintball produces eye injuries at rates far above sports with larger balls. Say it in those words. The bone that protects your eye from a baseball cannot protect it from something this small.

The parts of the eye that fail, named once

Four ways a paintball takes an eye

Corneal abrasion. The lowest threshold injury and the most common. The surface epithelium is scraped away. Painful, usually recoverable, and important mostly because it proves the projectile reached the eye.

Hyphema. Blood in the anterior chamber from torn iris vessels. It is the signature paintball injury and a marker of serious blunt loading, because the compression that tore those vessels was transmitted through the whole globe. It carries downstream risks including elevated intraocular pressure and rebleeding.

Globe rupture. The pressure vessel fails. The ball compresses the globe along the impact axis, and because the vitreous cannot compress it forces the globe to bulge sideways. The cornea or sclera tears where the stress is highest, usually at the limbus or at the muscle insertions, where the sclera is thinnest. Contents may extrude. This is the injury that leads to removal of the eye.

Posterior segment damage. Retinal tears and detachments, choroidal rupture, vitreous hemorrhage, and optic nerve avulsion, all without any hole in the eye. An eye that looks intact from the outside can be blind. That is the orange, in the demonstration from Chapter 1.

The published thresholds, in one table

Table 5.1 Published ocular injury thresholds from the impact biomechanics literature. Units differ between studies. Read the methodological warning below before using any of these in testimony.

Two entries deserve emphasis. The intraocular pressure range tops out at 26,426 millimeters of mercury, against a normal pressure in the low tens. The impact transient is on the order of a thousand times normal, briefly, which is why an eye can be destroyed by something that leaves the surrounding face unmarked.

The second is the bridge from ballistics to ophthalmology. Weaver and colleagues found that "area-normalized kinetic energy was the best single predictor of peak stress and pressure." That sentence lets a ballistics measurement speak to an ocular outcome, and it sets the trap described below.

Do not do the naive arithmetic and put it in a report

Take the rupture threshold of 35,519 joules per square meter and a 3.0 gram paintball at 300 feet per second, which by my calculation carries 12.5 joules. A 17.27 millimeter sphere has a cross sectional area of 2.343 times ten to the minus four square meters, so the quotient is roughly 53,500 joules per square meter, above the threshold.

Do the same to a 0.20 gram airsoft pellet at 350 feet per second. Published energy, 1.138 joules. Cross sectional area of a six millimeter sphere, 2.827 times ten to the minus five square meters. The quotient is roughly 40,300 joules per square meter, also above the threshold.

By that arithmetic a standard airsoft pellet at a common close quarters velocity has a better than fifty percent chance of rupturing a human globe, and the clinical series do not remotely support that. Khalaily's twenty six patient airsoft cohort found traumatic cataract in 11.5 percent and iris dialysis in 3.8 percent, not a majority of ruptured globes. Kennedy's airsoft risk function work found near universal corneal abrasion and hyphema above seventy five percent, which are lower threshold injuries, not rupture.

Use this literature comparatively. Four propositions come out of it, and I will say all four on the stand. An unprotected eye is injured at loads far below what the tissue around it tolerates. Abrasion happens at roughly one fifteenth the load rupture requires. Paintball impact energies sit where rupture is a real outcome, not a remote one. And the clinical series match the biomechanics: about half of paintball eye injuries end at 20/200 or worse.

Why some eyes fail and others survive the same hit

Identical impacts produce different outcomes for reasons that are not mysterious. An oblique strike glances and delivers less normal force. A partly closed lid absorbs and spreads energy. Scleral thickness is not uniform, and it is thinnest just behind the muscle insertions, a common rupture location. Prior ocular surgery leaves a permanently weakened wound, so an eye with a previous cataract incision or refractive surgery flap is a structurally different vessel.

Axial length matters too. Takahashi and colleagues modeled airsoft impact by finite element analysis across eyes of varying axial lengths and found hyperopic eyes, which are shorter, most likely to deform. The defense will argue the plaintiff's eye must have been unusually fragile. Some eyes are. The defendant took the eye as he found it.

The Standards and the Gaps

Four written standards touch this litigation, and the most useful thing about them is what they leave out. No consensus standard covers barrel blocking devices, netting, field construction, or separating spectators from players. That absence is not a defense. It moves the standard of care onto insurer underwriting requirements and industry custom, both provable, and the defendant in an unsupervised backyard case met neither.

F1776 governs paintball eye, face, and head protection

American Society for Testing and Materials standard F1776, current edition F1776-26, is the Standard Specification for Eye, Face, and Head Protective Devices for Paintball Sports. It is active, thirteen pages, last updated May 20, 2026. The title changed from the older Eye Protective Devices for Paintball Sports, which matters if you are working with documents from the earlier era. The scope, verbatim: "This specification applies to eye, face, and head protective devices, designed for use by players of the sport of paintball, which minimize or significantly reduce injury to the eye, adnexa of eye, face, and head due to paintball impact or penetration, or both."

The standard defines three protection tiers and specifies tests for field of view, refractive tolerances, astigmatism, power imbalance, prism imbalance, vertical and horizontal imbalance, luminous transmittance, haze, optical quality, and physical lens defects. Chapter 7 works through what those tests mean in practice.

F2272 governs the markers, and it absorbed the warnings standard in 2008

American Society for Testing and Materials standard F2272, current edition F2272-26, is the Standard Specification for Paintball Markers. Active, five pages, under Subcommittee F08.24, retitled from F2272-03, Paintball Markers (Limited Modes). It covers recreational markers propelled by compressed gas and expressly excludes markers made for law enforcement, military, scientific, and theatrical use.

Three requirements matter, and I quote them because the wording is the argument. The standard mandates "appropriate literature, packaging, design, and disabling devices." It requires that the cocking or pumping mechanism not cause unintentional discharge in normal operation. And it requires that markers resist accidental discharge from specified jolts. A manufacturer cannot satisfy the first clause by putting a warning in the manual and stopping there, because design and disabling devices are separate listed elements. Chapter 10 makes this the hook for the residual gas claim.

American Society for Testing and Materials standard F2041-00, the Standard Specification for Paintball Marker Warnings, was withdrawn in 2008 and absorbed into F2272. For any marker manufactured between 2000 and 2008, F2041 was the operative warnings standard and it is the document you compare the packaging against. Testing a 2004 marker against the current F2272 is the wrong analysis, and it is correctable on cross.

F2879 governs airsoft eye protection, and it concedes the Z87.1 point

American Society for Testing and Materials standard F2879, current edition F2879-22, is the Standard Specification for Eye Protective Devices for Airsoft Sports, intended to "minimize or significantly reduce injury to the eye and adnexa as a result of impact and penetration of airsoft projectiles." It differs from the paintball standard in two ways. It protects the eyes and immediate facial area only, where F1776 covers eye, face, and head. And it separates competition shooting at backstops, where eyewear meeting Z87.1 may suffice, from tactical airsoft, where it does not.

Why Z87.1 is not the paintball standard

American National Standards Institute and International Safety Equipment Association standard Z87.1-2020 is the American National Standard for Occupational and Educational Personal Eye and Face Protection Devices. Its scope covers protectors for "impact, non-ionizing radiation and liquid splash exposures in occupational and educational environments including, but not limited to, machinery operations, material welding and cutting, chemical handling, and assembly operations." That is a shop and laboratory standard, written for flying chips, splashes, and radiation. It contains no paintball impact criterion, no requirement that the device seal to the face, and no provision for a twelve joule impact from a seventeen millimeter deformable sphere. Three arguments prove it, and the third is the strongest.

Scope. The document says what it is for, and paintball is not on the list.

Absence of the relevant test. Z87.1 impact requirements are built around small high velocity fragments and larger low velocity drops, not a deformable projectile of paintball mass at paintball velocity. There is also no seal to face requirement, so a device can comply fully and still let a projectile enter from beneath the lens.

The negative inference from F2879. The airsoft standard says Z87.1 may suffice for competition shooting at backstops and does not suffice for tactical play. That is a standards body conceding, in a published document, that Z87.1 is inadequate for player versus player impact. If it is inadequate for a one joule pellet, it is inadequate for a twelve joule paintball. If Z87.1 were sufficient, F1776 would never have been written.

The European standard is EN 166:2001, Personal Eye Protection Specifications, which uses impact classes designated S, F, B, and A. I have not been able to retrieve the test velocities for each class and will not state them from memory. That item is in the verification punch list.

Table 6.1 The four standards side by side

Three gaps where no standard exists at all

No barrel blocking device standard. Subcommittee F08.24 lists only F2041, withdrawn, and F2272, active. No consensus specification states what a barrel blocking device must withstand, how it must retain, or how it must be tested. The requirement lives inside the F2272 disabling devices clause and nowhere else.

No netting or field construction standard. Nothing specifies netting height, mesh size, tensile strength, setback distance, or attachment method for a paintball field.

No spectator separation standard. Nothing specifies how far a non participant must be from active play, or what must be between them.

The bystander case is therefore tried in a zone with no written specification at all, which is where Ernst v. Church was tried.

Where the standard of care comes from when no standard exists

Absence of a consensus standard does not mean absence of a duty. It means the duty is proved a different way, from four sources.

Insurer underwriting requirements. No commercial paintball field operates without liability insurance, and no carrier writes that policy without conditions. My own carrier's conditions specify mask requirements, barrel blocking device requirements, velocity limits with enforcement, waivers, staff to player ratios, and physical separation of spectators. They are written, discoverable, and uniform across the industry because a small number of carriers write most of the book. Subpoena the underwriting file and the application from any commercial field in the venue. What the carrier requires as a condition of coverage is what the industry does, documented by a party with money at risk and no stake in this lawsuit.

Industry custom, proved by operators. Get the posted rules, waiver forms, chronograph logs, staff training materials, and field maps from three commercial fields in the venue. Uniformity across independent operators is the proof. When five fields in one county all require a barrel blocking device from the moment a player leaves the netted area, a host who did not do it departed from the custom.

The manufacturer's own instructions. The manual and the packaging state the conditions under which the product is safe. A host who violates them has departed from a standard the defendant's own supplier set.

The operator's own written procedures. If the defendant has standard operating procedures and did not follow them, the case is close to over. If the defendant has none, that is the finding.

Masks and Goggles

A paintball mask is the only thing between a twelve joule projectile and a structure that fails at a fraction of that loading. When a compliant mask is on the face, the injury does not happen, so nearly every paintball eye loss case is a case about why the mask was off, was wrong, or was defeated.

What F1776 actually requires

F1776 defines three protection tiers, so the first question about any mask is not whether it is certified but which tier, and whether that tier matches the use. It also specifies field of view, refractive tolerances, astigmatism, power imbalance, prism imbalance, vertical and horizontal imbalance, luminous transmittance, haze, optical quality, and physical lens defects. Practitioners skip these optical tests. Do not. Every one is a safety requirement with a causation pathway.

• Field of view. A player who cannot see laterally does not see a person entering the play area, which in a bystander case is a direct causal link.
• Refractive tolerance, astigmatism, prism and power imbalance. A lens that bends light unevenly shifts apparent target position and causes eye strain and headache. Prism imbalance between the two eyes is the defect that makes a player misjudge distance.
• Luminous transmittance. A dark lens on a shaded wooded field hides a small person standing at the edge of it.
• Haze and optical quality. A scratched or scuffed lens scatters light, and scattered light is functionally the same problem as fog.
• Physical lens defects. Bubbles, inclusions, and waves are optical defects and also stress concentrators where an impact starts a crack.

The seal to the face is the failure nobody tests for

A lens can stop everything and the device can still fail, because the paintball only has to reach the eye. The paths are around the lens, under the chin, through the ear opening on a poorly fitted unit, or beneath a stretched strap.

Fit is specific and checkable. The device must sit against the forehead and cheekbones with no gap you can pass a pencil through, the strap must be tight enough that the mask does not shift when the head is shaken hard, and the chin must be inside the shield. An adult mask on a child's face fails all three, and a five year old at a backyard event is wearing an adult mask if he is wearing one at all.

Get the F1776 impact test velocity and projectile mass from the purchased standard, because the adequacy analysis depends on comparing them against the velocity in your case. If your marker chronographed at 340 feet per second and the standard tests lower, that is a material fact.

Fogging is a causation pathway, not an inconvenience

The equipment literature states it plainly: "fogging masks can be a significant hazard while playing." The hazard is not that the player cannot see. It is what he does about it. The reflex is to lift the mask, wipe the lens, and drop it back, which takes about three seconds on an active field where nobody has called a hold. Every eye injury I have seen on a supervised commercial field involved a mask that came off, and fogging is the most common reason.

Anti fog design is a safety feature, not a comfort feature. Thermal lenses, anti fog coatings, ventilation channels, and fans all mitigate a documented injury pathway, so whether the mask in evidence has a single or dual pane lens is a fact you need.

How to examine a mask after an incident

Do not clean or disassemble it. Photograph it as received, from six sides, with a scale in frame. Then document each of the following.

1. Markings. Manufacturer, model, date of manufacture, and any standard compliance marking on the frame or lens. Photograph the marking close, in raking light.
2. Impact witness marks. Paint residue, a dwell mark, a crazing pattern, or a crack. Location on the lens tells you the impact angle. Absence of any impact mark on a mask a plaintiff was allegedly wearing is decisive.
3. Lens construction. Single or dual pane. If dual pane, whether the seal is intact and whether moisture sits between the layers.
4. Fog state. Interior film, wiped streaks, or finger marks. A wipe pattern on the inside of a lens proves somebody lifted this mask during play.
5. Strap condition. Elasticity, stretch, and whether the adjustment was set for a child or an adult. Photograph it as found before touching it.
6. Fit against the actual wearer. If the wearer is available and willing, fit the mask and photograph the gaps. If not, use a headform sized to his measurements.
7. Age and degradation. Polycarbonate embrittles under ultraviolet exposure and is attacked by many solvents, so a mask that lived in a truck bed for four seasons is not the mask that was certified. Ammonia based glass cleaner degrades lenses.
8. Provenance. Who owned it, who supplied it that day, whether it was rented or personal, and whether a staff member checked its fit on this wearer.

Chapter 15 puts this in the larger evidence sequence, including preservation letters and chain of custody.

Barrel Blocking Devices

A barrel blocking device stands in front of the projectile, so it works whether or not the internals are sound, the safety is engaged, or anyone knew the marker was charged. That is the failure mode that took Nathan Earnst's eye. No consensus standard covers it, but a near universal industry custom does, and that custom is provable.

The plug came first and it failed for two reasons

A barrel plug is "a plastic or rubber plug that fits snugly into the muzzle end of the marker's barrel, like a wine cork." It relies on friction against the bore to stay put.

The first failure is contamination. Paintballs break inside barrels routinely, "lining the barrel with paint and drastically affecting accuracy," and a bore coated in glycol based fill is a lubricated bore. The friction the plug depends on drops toward nothing and the plug becomes a projectile with a paintball behind it.

The second failure is rate of fire, and it killed the design. With "modern electronic markers having 'automatic' and 'burst' modes of fire," a single trigger pull can "dislodge the plug, potentially causing injury." The first shot pushes the plug free and the second and third leave an open muzzle. A device that stops one shot does not stop an accidental discharge on a burst capable marker.

A third problem matters in a bystander case. A plug ejected under gas pressure is itself a hard projectile, leaving the muzzle at an unpredictable angle.

The sock works because it does not rely on friction

A barrel sock is "a cloth pouch with an adjustable elastic cord." The pouch covers the muzzle and the cord cinches around the marker body or barrel. If the marker fires, the ball "will generally break in the pouch after leaving the barrel."

Three properties make it the industry answer. It is retained by a cord anchored behind the muzzle rather than by friction in the bore, so gas pressure does not remove it. It is "easy to install and remove," which matters because a device that is annoying gets left off. And it "will remain in place over the barrel even after repeated shots," which answers the burst fire failure.

The sock captures the ball rather than deflecting it. Fabric deformation and the breaking ball absorb the energy, and the paint left in the pouch records that a discharge occurred.

When the device comes off, and who says so

The rule at every commercial field I know of, including mine, is a boundary rule. The device goes on before the marker leaves the netted playing area and comes off only inside a designated area with a staff member present.

The correct order is: game ends, staff calls the field clear, players install barrel blocking devices while still masked and inside the netting, staff checks every muzzle, players exit, masks come off. Reverse any two steps and you have a violation.

At Forresthill the covers came off before the players left the playing area, which removed the device at the moment it was most needed, in the zone where markers are still charged and people are moving unpredictably.

The critical deposition question is not whether the rule existed but who was responsible for verifying it. A rule with no named enforcer is not a rule. On my field the referee checks every muzzle before the gate opens, and if he cannot see a blocking device the gate does not open.

The chain of custody problem when the device is missing

After a serious injury the marker gets picked up, carried inside, and put in a case. Days later an investigator asks for it and the barrel blocking device is not with it. That absence proves nothing by itself and is the most contested fact in these cases. The defense says the device was on and fell off. The plaintiff says it was never on.

Six things resolve it, and you need all six early.

1. Photographs taken before anyone touched anything. Teenagers photograph everything. Subpoena phones and cloud accounts before the storage rolls over.
2. Count the devices against the markers. If eight markers were in use and the host can produce three devices, that is a number.
3. Paint inside the pouch. A sock that captured a discharge carries paint. A clean pouch was not in front of a fired muzzle.
4. Purchase records. Did the host ever buy barrel blocking devices. In many backyard cases a receipt search ends the argument.
5. The condition of the marker's muzzle. Paint spatter at the muzzle crown tells you whether anything was in front of it.
6. The other players. Ask each separately what was on his own muzzle and on the muzzle of the marker that fired. Inconsistency across accounts is itself the finding, and Chapter 12 explains why.

Chronographs and Velocity Control

Velocity drifts all day, and an instrument costing less than a case of paint, plus a hex key, settles it in under a minute per marker. A field that does not chronograph chose not to know something it could have known for nothing, which is the cleanest negligence argument in this litigation.

Optical and radar chronographs work differently and fail differently

An optical chronograph "consists of two sensing areas framed by rods topped by diffusing screens or artificial lighting above (or below) along with optical sensors that detect the passage of the bullet. The time it takes the bullet to travel the distance between the sensors is measured electronically from which velocity is calculated and displayed." Advanced instruments use Doppler radar to measure projectiles in free flight, or magnetic field sensors mounted at the muzzle.

Table 9.1 Chronograph types in paintball field conditions

The demonstrative script from Chapter 1 describes the field procedure in one sentence: markers "must be tested and calibrated every time they are used, using an inexpensive radar to check speed, and an Allen wrench to adjust the gun."

How to chronograph a marker correctly

The measurement is easy to take and easy to take wrong.

1. Chronograph with the paint that will actually be played, from the same lot, not with old balls kept in a drawer for the purpose.
2. Chronograph with the bottle at operating condition, not fresh off a fill and not nearly empty.
3. Fire at least three shots and record all three. One shot is not a measurement, and the spread is a diagnostic in its own right. A spread over about fifteen feet per second points to a bore mismatch, a failing regulator, or liquid carbon dioxide.
4. Record the highest reading, not the average, and set the marker so the highest reading is inside the limit.
5. Record ambient temperature and propellant type on the same line.
6. Adjust with the velocity adjuster screw and re-measure. Never adjust and release without a second measurement.
7. Re-chronograph after any change: new paint lot, new bottle, new barrel, any disassembly, and after a significant temperature swing on carbon dioxide.

My field's rule is chronograph on entry, every player, every session, and again any time a player changes paint or gas. I chronograph carbon dioxide markers a second time in the afternoon on days when the temperature climbs more than about twenty degrees. That rule exists because of Figure 3.1, not because a standard told me to.

What a chronograph log must contain to be worth anything

A log with a date and a checkmark is worthless in litigation and in operation. It has to identify the specific marker, the specific measurement, and the person who took it.

Each column earns its place. Date and time defeat the argument that the log was reconstructed. Temperature and gas type are the carbon dioxide drift analysis. Marker identification ties the reading to the object in evidence. Paint lot is the bore match variable. Three readings show the spread. The adjustment column proves the field acted on the measurement. Staff initials give you a witness with personal knowledge, which is the difference between a business record and a piece of paper.

Adjusting a marker, and what "calibrated" really means

On most markers the velocity adjuster is a hex screw that changes mainspring preload or gas volume per shot. Clockwise usually raises velocity, counterclockwise lowers it. Adjust a quarter turn at a time, then re-measure. Some designs adjust at the regulator instead. Electropneumatic markers may allow adjustment in the board's menu, in which case the setting and board revision belong in the log.

The word "calibrated" in my trial script is field usage meaning set into the limit and verified. A chronograph can itself drift, and a serious operation checks it periodically against a second instrument. If a defendant produces a log, ask when the chronograph was last checked against anything. Nobody ever has an answer.

What the absence of a log proves

An operator with no chronograph log has no evidence that any marker on the property was ever within any limit. That turns the velocity question from a disputed fact into an admission of ignorance, and puts the burden of the unknown on the party who chose not to measure. In a backyard case the finding is usually more basic: the host never owned the instrument. Ask for the receipt.

The Gas That Stays in the Gun

Take the supply bottle off a paintball marker and most adults will tell you the gun is now safe. On blowback and stacked tube designs that is wrong. The marker holds enough charged volume downstream of the valve to cycle one to three more times, and it will still fire at damaging velocity. The man in the Forresthill case unscrewed his bottle, pulled his barrel, and by every ordinary standard of care believed he had rendered the object inert. He had not, and a five year old lost an eye.

The engineering, in the order the gas moves

Chapter 2 traced the gas path with the bottle attached. Now trace it with the bottle gone.

When the bottle unscrews, the bottle valve closes and supply stops at the air source adapter. Nothing else changes. The regulator body is still full of gas at whatever pressure it was holding, the passage from the regulator to the valve chamber is still full, and the valve chamber, the reservoir the next shot is drawn from, is still full and still sealed behind the valve stem. On a stacked tube design the transfer passage between the lower and upper tubes adds more volume, all of it downstream of the supply.

The mechanical energy is also still stored. The mainspring is compressed with the hammer held by the sear, and the trigger still releases the sear.

So pull the trigger. The hammer drives forward, strikes the valve stem, and unseats it. The gas in the valve chamber and the regulator body discharges into the transfer passage and behind the bolt exactly as it did with the bottle attached. If a ball is in the breech, it goes down the barrel. The pressure is lower than a fully supplied shot and falls with each cycle, but the first residual shot from a marker that was at operating pressure a moment earlier is a real shot.

Whether the marker recocks for a second shot depends on how much gas is left after the first, which is why the practical range is one to three shots rather than a fixed number. Larger internal volume, higher operating pressure, and a warm marker all yield more shots. That is why the answer in a report has to come from testing the exemplar, not from a rule of thumb.

Why a reasonable adult believes an unbottled marker is inert

This part decides the case, and it is not technical. It is about what people expect.

Every firearm most adults have encountered becomes safe when the ammunition source is removed and the chamber is cleared. Remove the magazine, rack the slide, look in the chamber, and the object is inert. That model is taught in every hunter safety course in the country and it is correct for cartridge firearms. A paintball marker appears to follow the same logic: the energy source is visible, it screws off, the paint sits separately in the hopper and can be dumped, and once both are gone the object looks empty.

The trap is that the energy source is a gas, invisible, stored in an internal volume with no external indication of its state. There is no way to look at an unbottled marker and see whether it is charged. Many designs have no gauge downstream of the regulator, and where a gauge exists nobody has been told to look at it.

That is what "counter-intuitively dangerous" means in my trial script, and it is why the failure belongs to the design rather than to the man holding it. A reasonable adult applied a correct and universally taught safety model and the product did not behave the way the model predicts. When a product defeats a reasonable user's correct mental model and gives him no way to detect the difference, the defect is the product's.

What the manual says and where it says it

The Forresthill marker's manual carried the safety information, and my trial script makes the point that reading "even just the first two pages" would have disclosed the danger. Keep two arguments separate here, because they lead to different places.

Against the host. The information was available and free. A host who supplies markers to teenagers without reading the manual has not met the lowest possible standard of care. Chapter 13 develops what a non professional host is expected to know.

Against the manufacturer. Information buried in a manual is not a warning. Manuals are separated from the product within days of purchase and almost never reach the third party holding the marker at a church youth event. A hazard that beats the user's correct mental model, and that he cannot see by looking, needs a warning at the hazard, not on page two of a document that went out with the packaging. Chapter 17 works through warning adequacy on the box versus in the manual.

When you get the exemplar manual, document the edition and date, the page and section, the exact language, the typography and prominence, whether the same warning appears on the marker body, and whether it appears on the carton. Then find out whether the manual was in the box the host received, and whether the marker was bought used, which is how most of these markers travel.

Design defect and warnings defect at the same time

This single fact pattern supports two independent theories, and F2272 supplies the framework for both. The standard mandates "appropriate literature, packaging, design, and disabling devices." Literature and packaging are the warnings side. Design and disabling devices are the design side. A manufacturer that put a line in the manual satisfied at most one of the four.

The design theory. A marker that retains a fireable charge after its visible energy source is removed, with no indication of that state and no simple means to discharge it, is defectively designed. The alternatives are not exotic. A manual bleed valve or purge button vents residual pressure with one press, and such devices exist on other pneumatic products. A downstream pressure gauge lets a user see the state. A mechanical interlock that dumps residual pressure when the air source adapter is unthreaded is straightforward mechanical engineering. Each is a feasible alternative design, and feasibility is what a risk utility analysis turns on. Chapter 17 sets out the doctrine.

The warnings theory. The hazard is not obvious, not detectable by inspection, and contrary to the safety model every user brings to the object. Those are the conditions that make a warning necessary and placement critical. A warning that does not reach the person holding the marker at the moment he decides it is safe has not done the job.

The jolt requirement is a third hook. F2272 requires markers to resist accidental discharge from specified jolts, so ask what happens when a marker with a residual charge is dropped. If the jolt test is run only on a fully supplied marker, the standard has a gap. If it is run on an unbottled marker, the test data will tell you whether the manufacturer knew about the residual charge. Either answer is useful, which is why it is in the verification punch list.

How to prove it: the bench test protocol

The proof is a test you run and film, on an exemplar of the same make, model, and revision, purchased separately, so the evidence marker is never cycled.

1. Document the exemplar: make, model, serial, revision, date of manufacture, provenance. Photograph it as received.
2. Install a gauge downstream of the regulator if the design permits, so pressure is recorded rather than inferred.
3. Bottle the marker, bring it to operating pressure, and chronograph a normal shot for a baseline.
4. Unscrew the bottle completely and set it aside on camera, with the camera never cutting away.
5. Load a ball and point the muzzle into a witness medium, at the standoff distance in your case if you can establish it.
6. Fire, on camera, through a chronograph. Record the velocity of every residual shot until the marker will no longer cycle, and count the shots.
7. Repeat the sequence at least five times, recording ambient temperature each run.
8. Repeat with the barrel removed, if that is what happened in your case.
9. Photograph the witness medium after each run.
10. Then run the negative control: dry fire until the marker will no longer cycle, verify zero on the gauge, load a ball, and pull the trigger. Nothing happens. That control makes the demonstration honest and teaches the jury the procedure that would have prevented the injury.

The three sentences that carry this on direct

Removing the bottle stops the supply and does not empty the marker. There is no way to look at the marker and tell. The only way to make it safe is to fire it until it stops, and nobody told him that.

Then put the marker on the table in front of the jury, unbottle it, and fire it into the witness medium. Chapter 16 covers how to build that so it survives a challenge.

Field Design and the Bystander

A paintball field is a machine for keeping projectiles inside a boundary and people who did not consent to be shot outside it. No consensus standard specifies how to build one. The elements below are near universal across commercial operations, they are conditions of insurance coverage, and they are what my own park runs. A backyard event has none of them.

The seven elements of a field that works

Netting. A ball fired upward at a running target arcs, so netting that stops a flat trajectory at four feet does nothing about a lob. Commercial fields run netting well above head height with the top edge angled inward. Check mesh size, tension, attachment, gaps at seams and gates, and whether the net reaches the ground. The gap under a net is the classic defect, because it is the exact height of a small child.

Boundaries a player can see. Netting defines the boundary physically and flagging tape or paint defines it visually. Both are needed, because a player pursuing a target does not think about where the field ends.

The staging area. Players gear up and pass through here with markers in hand, so it must sit outside the net and out of every line of fire.

The dead zone. The one place on the property where an unprotected eye is expected, so it must be far from the playing area, screened, and clearly marked. On my field it is the only place a mask may come off and the only place a barrel blocking device may come off to work on a marker.

The chronograph station. A choke point at the entry to the playing area, staffed, where every marker is measured, logged, and adjusted before it goes in. Chapter 9 gives the log form.

Entry and exit control. One or two designated gates, staffed. The gate is where masks go on and barrel blocking devices come off, in that order and under supervision. Uncontrolled entry is how a person who is not playing ends up inside a playing area.

The spectator line. A defined position outside the netting, with distance and a barrier between the watchers and the playing area. Spectators show up whether you planned for them or not, and if you give them no place to stand they pick the most interesting place, which is the most dangerous one.

One administrative control belongs on the list: the minimum engagement distance, commonly four and a half meters or fifteen feet, inside which a player must call a surrender rather than shoot. Its existence proves the industry recognizes point blank shots as a distinct hazard. Nathan Earnst was shot at point blank range.

The bystander is the most exposed person on the property

Players wear masks certified to stop the exact projectile in use, they know the game is running, they watch for movement, and they consented. The bystander has no mask, no idea where the lines of fire run, no training, and no consent. Two structural facts compound it. Bystanders stand where the action is, because that is what makes it worth watching, and bystanders at informal events are disproportionately young, because the little brother who is too small to play stands next to the game his brother is playing. The person with the least protection is in the most dangerous place at the least defensible age.

The epidemiology supports the concern indirectly. Conn and colleagues, using Consumer Product Safety Commission surveillance data, found a similar proportion of paintball injuries in or around the home, 28.4 percent, as at a paintball sports field, 26.3 percent. Chapter 14 explains why equal raw counts imply a far higher rate per exposure hour in the unsupervised setting.

Why the case law under-protects the person it should protect most

The doctrines that govern recreational injury were built around co-participants. Primary assumption of risk asks whether a plaintiff consented to the inherent risks of a sport, and all of that machinery assumes a plaintiff who chose to play. A bystander did not choose, so he falls outside the doctrine and the correct analysis returns the case to ordinary negligence. Chapter 21 writes that argument out carefully, because it is the most important legal move in a case like Forresthill and it is easy to state badly.

The spectator line is the physical implementation of a duty owed to a person who has not assumed any risk at all.

Who Is in Charge

"Adults were present" is not supervision. Every backyard case has adults present. The question is whether anyone had a defined role, the knowledge to perform it, the authority to stop play, and a record showing they did. You prove nobody was doing that job by asking for the paper the job generates.

What active adult supervision actually means

Five elements, and all five have to be present.

Designated. A specific person holds the safety role by name and the players know who it is. An adult who happens to be nearby is a bystander with a driver's license.

Knowledgeable. He has read the manual for the markers in use and knows how to chronograph, adjust velocity, fit a mask, and bleed residual pressure. My trial script frames the Forresthill failure as a question: "So where was the safety person? Who was checking to see if the players knew how their guns worked?"

Active. Watching the field, not the phone and not the grill, positioned where he can see, moving to maintain sightlines, and counting people.

Authorized. He can stop the game, take a marker away, and eject a player, and everyone present knows it. A supervisor who can only ask is not a supervisor. This element is the one most often missing at a church or scout event, where the person who knows the equipment is a teenager and the person with authority is an adult who does not.

Ratioed. One person cannot supervise an unbounded number of players across terrain he cannot see. No published standard sets a ratio. My field runs a referee per squad plus a staffed chronograph station and gate, and my insurer requires staffing levels as a condition of coverage. State it as one operator's practice and an underwriting requirement.

The safety officer role, written down

On a run field, one person owns safety and does nothing else. His duties, in order of the session:

1. Inspect and fit every mask before it goes on a face, sized to that face.
2. Chronograph every marker, log it, adjust it, and log the adjustment.
3. Verify a barrel blocking device on every muzzle before the gate opens.
4. Deliver the safety briefing, the same briefing every time, and confirm comprehension rather than asking whether anyone has questions.
5. Count players in and count them out.
6. Observe play, call holds, and enforce the minimum engagement distance.
7. Call the field clear, verify blocking devices back on, and only then open the gate.
8. Log incidents, including near misses and mask removals, with time and names.

Posting rules is not the same as enforcing them

My trial script separates three things that get collapsed into one: "Rules have to be posted, they have to be observed, and they have to be enforced." Posted means physically present at the point of use, in text a twelve year old can read, at the gate and in the staging area. A rule in a binder in an office is not posted. Observed means the players actually follow them, which you can only know by watching. Enforced means consequences, applied consistently and documented. A field that has never ejected anyone has never enforced anything.

The safety officer's briefing is where posting becomes observation. It covers masks, barrel blocking devices, velocity, boundaries, the minimum engagement distance, surrender rules, how to call a hold, and where the dead zone is, and it ends with a demonstration rather than a question. Watching a player install a barrel blocking device on his own marker tells you more than asking him whether he understands.

How you prove nobody was in charge

Supervision generates paper. Its absence is provable by requesting the paper and receiving nothing.

Table 12.1 The documentary trail of supervision, and what its absence establishes

Inconsistent witness accounts are the second proof. In a supervised operation everyone gives the same account of the rules, because everyone heard the same briefing. When five witnesses give five different answers about who was in charge, whether masks were required, and when barrel blocking devices came off, that is affirmative evidence that no common instruction was ever delivered. Depose each participant separately, ask the same short list, and chart the answers side by side. The chart is an exhibit.

Kids, Camps, and Churches

Most paintball injuries to children happen at events organized by adults with good intentions and no idea what they are doing. A church, a scout troop, or a youth group decides paintball would be fun, borrows equipment from whoever has some, and turns teenagers loose in a yard. Nobody thinks he is being reckless, which is why the standard applied to them cannot be a subjective one.

Why teenagers fail at safety vigilance

My trial script puts it plainly: "Safely handling any kind of gun requires maturity. And it's pretty well known that most teenagers lack the maturity to maintain proper safety vigilance." And then, from my own experience running a licensed camp: "I know that even kids who seem mature, still don't always behave the way they should when there are no grownups around."

The failure is not stupidity or defiance. Safety vigilance is a sustained attention task performed while doing something exciting, and it competes directly with the excitement. Four failure modes show up over and over.

• Vigilance decays over a session. Rules are followed for the first twenty minutes and drift after that. Adults do this too, and adolescents do it faster.
• Peers override rules. A rule that makes a fourteen year old look cautious in front of his friends loses.
• Muzzle discipline collapses first. Muzzle direction requires constant attention and gives no feedback when violated, which makes it the first rule to go.
• The equipment gets treated as a toy between games. The dangerous behavior in most of these cases happens during a break, not during play. Nathan Earnst was shot by a marker its owner had just tried to make safe.

Controls for youth events therefore cannot depend on continuous adolescent attention. They have to be physical and adults have to enforce them: netting, barrel blocking devices verified by a named person, masks that stay on because staff will not open the gate otherwise, and a spectator line drawn on the ground.

A licensed operation is a different thing from a backyard event

I run a state licensed summer camp, and licensure is not a formality. It brings staff to camper ratios, background checks, training requirements, health and safety plans, incident reporting, inspection, and an insurer who reads the plan. Those obligations are written down and enforceable by someone other than a plaintiff.

Table 13.1 Licensed operation compared to an informal youth event

What a host who is not in the business is expected to know

The defense theme in every one of these cases is that the host is a volunteer, not a professional, and cannot be held to a professional's standard. The answer has three parts, and none of them require the host to be an expert.

One who undertakes a dangerous activity accepts the duty that comes with it. The standard of care attaches to the activity, not to the actor's job title. A person who hosts an activity involving projectile weapons and children is measured by the risk he created, not by how much he happened to know about it.

The manufacturer told him. The warning was on the box, larger than the product name, with the instruction to use the product only with adult supervision, and the residual gas hazard was in the first pages of the manual. That is free documentation that came with the object and required only that somebody read it.

Not knowing is the breach. A host who lacks the knowledge to run the activity safely should hire someone who has it or not run it. Commercial fields exist in nearly every metropolitan area, so the alternative to an unsupervised backyard game is paintball at a field with netting, a chronograph, referees, and insurance, for about the price of pizza for the same group. That framing does not ask the jury to think badly of the host. It asks them to find that he took on something he did not understand and did not check, when checking was free and the alternative was down the road.

Age restrictions, and where they come from

Commercial fields commonly set minimum ages, typically ten to twelve years old, by field policy and insurer requirement rather than by statute. Some jurisdictions legislate. New York Penal Law section 265.05 makes it unlawful for a person under sixteen to possess any air gun, spring gun, or other weapon propelled by spring or air, which reaches both paintball markers and airsoft guns. Chapter 18 develops it against retailers and Chapter 19 against hosts.

Whatever the local rule, establish the shooter's age precisely and early, along with who handed him the marker and what that person knew about him.

How Often This Happens

The published literature on paintball injury is unusually favorable to a plaintiff for one reason: paintball produces worse visual outcomes than any other shooting sport that has been studied. That is what the numbers say, and the numbers come from the Consumer Product Safety Commission's national surveillance system and from hospital based series in peer reviewed ophthalmology journals.

The national surveillance study, and the number that matters

Conn, Annest, Gilchrist, and Ryan, all Centers for Disease Control authors, published "Injuries from paintball game related activities in the United States, 1997-2001" in Injury Prevention in June 2004, using National Electronic Injury Surveillance System data. Their headline estimate, verbatim: "An estimated 11 998 persons ≥7 years with paintball game related injuries were treated in emergency departments from 1997-2001, with an annual average rate of 4.5 per 10 000 participants (95% CI 3.3 to 5.7)."

The distribution is where the case is. The eye was the most common body part affected, at 42.7 percent. Among those struck by paintballs, 83.7 percent were hit in the head and neck area, and 69.1 percent of those injuries involved the eye only. Ninety four percent of the injured were male. The highest rate was among 18 to 24 year olds at 4.9 per 10,000, while the largest share of injuries, 35.7 percent, fell among ages 12 to 17.

When a paintball hits a person in the head, the injury is confined to the eye alone about seven times in ten. That is the orbital geometry from Chapter 5, counted in a national data set, and it answers the defense claim that an eye injury was an unforeseeable freak. The eye is not one of many things that get hurt. It is the thing that gets hurt.

The pediatric literature

Listman, in Pediatrics, January 2004, supplies the trend the table cannot show: emergency department treated paintball eye injuries rose from an estimated 545 in 1998 to more than 1,200 in 2000, and the injured children were "predominantly boys playing in unsupervised settings without eye protection."

Jones, Kistamgari, and Smith, in Pediatrics, December 2019, put paintball in proportion: "An estimated 364 133 children <18 years old were treated in US emergency departments for injuries related to nonpowder firearms from 1990 to 2016, averaging 13 486 children annually." Paintball accounted for 3.0 percent of that total, and 87.1 percent of the injured were boys. Concede that paintball is a small share of a large problem. It is true, and conceding it costs nothing.

Visual outcomes across the clinical series

Table 14.1 Published paintball and airsoft ocular injury outcomes

Three findings in that table do most of the work.

Roughly half of paintball eye injuries end at 20/200 or worse. Listman found 43 percent with permanent loss at that level, Alliman 50 percent, Thach 8 of 13, and Pahk and Adelman 43 percent. Four independent series converging on the same number is a robust finding, and 20/200 is the threshold for legal blindness in the affected eye.

Paintball is worse than the rest of the shooting sports. Dockery's comparison puts paintball at a mean final acuity of 20/500, worse than every other shooting sport studied, with airsoft at 20/200. Haring's odds ratio of 4.75 against football, confidence interval 2.21 to 10.19, is the same finding from a different direction.

Regulated toys are safe and these are not toys. Bisplinghoff and Duma tested regulated projectile shooting toys and found no risk of hyphema, lens dislocation, retinal damage, or globe rupture, with maximum corneal abrasion risk of 5.9 percent. Products regulated as toys do not take eyes. A paintball marker does, because it is not a toy.

Supervised versus unsupervised, and how to argue an inference honestly

Every one of these cases turns on whether unsupervised play is more dangerous than supervised play. Common sense says obviously, but the literature does not answer it directly, and you need to know that before a defense expert tells the jury so. No study appears to compare injury rates per participant hour at supervised commercial fields against unsupervised private play. Two data points exist.

Conn and colleagues reported the setting distribution, verbatim: "A similar proportion of persons were reported to be injured in or around the home (28.4%) and at a paintball sports field (26.3%)." Unknown locale accounted for another 37.7 percent. Listman described the injured children as "predominantly boys playing in unsupervised settings without eye protection."

Argue from that without overstating it. Raw injury counts are roughly equal between the home and the commercial field, but participation hours are not. Commercial fields host organized play for hours at a time, week after week, and account for the overwhelming majority of all paintball played in the United States, while backyard play is occasional. When two settings produce similar raw counts and one accounts for far more exposure, the rate per exposure hour in the smaller setting must be far higher.

That is an inference, not a finding, because the denominator, participant hours by setting, is not in the paper. Say so on direct before opposing counsel says it for you. An expert who volunteers the limit of his own data is believed on everything else.

Operational data helps if you have it. I know how many player days my park runs in a year, how many eye injuries have occurred in that time, and what controls produced that number. That is one operator's data, not a controlled comparison, and it is admissible for what it is.

Investigating the Case

The physical evidence in a paintball case degrades faster than in almost any other product case, because none of it looks like evidence. The marker gets cleaned because paint is sticky, the mask gets washed, the barrel blocking device disappears, and somebody re-bottles the marker and cycles it to show an investigator how it works, destroying the residual charge. Move fast and name things specifically.

The first seventy two hours

Four things in the first three days, in this order.

Send the preservation letter. Same day, naming every item individually, because a general demand to preserve evidence will not stop a well meaning person from wiping paint off a lens. Specify that the marker must not be cleaned, cycled, dry fired, disassembled, re-bottled, or degassed, and that any attached bottle stays attached.

Secure the digital record. Participant phones, cloud photo accounts, group chats, and social media posts from that day. This material is deleted or rolls over within weeks, so ask before anyone understands why it matters.

Get to the site. Vegetation changes, paint marks weather off, and yards get mowed. Photograph and measure first.

Identify the exemplar. Find the exact make, model, and revision and buy one. Every destructive test happens on the exemplar.

Securing the marker in the condition found

Photograph the marker where it lies, with a scale and a north reference. Then, before it moves, record whether a bottle is attached and what any gauge reads; fire mode and safety position; whether a barrel blocking device is present; whether a hopper is attached and how much paint is in it; whether a ball is visible in the breech; the velocity adjuster position in turns from bottom, without turning it further; and any broken paint, photographed before it dries.

Bag and tag with the bottle attached if it was attached, and transport it in a rigid case. Do not let anyone pull the trigger at any stage, including to demonstrate that it is safe.

If the design permits measurement of downstream pressure through a gauge port without cycling the marker, do it, document it, and film it. That measurement is the closest thing to a direct observation of the residual charge in the evidence marker, and it can only be taken once.

The full evidence checklist

Table 15.1 Evidence inventory for a paintball or airsoft injury case

Sequencing the witnesses

Interview separately, early, and in order. Start with the least invested: bystanders, siblings, and parents who were not organizing. Move next to the players, individually, before they compare notes. Take the shooter and the organizers last, after you know what everyone else said.

Ask every witness the same short list, so the answers can be charted. Who was in charge of safety. Were masks required and did anyone check. Was there a chronograph. What was on the muzzles and when did it come off. Where were the people who were not playing. What were you told before you started. That chart is the supervision exhibit from Chapter 12.

Reconstruction testing

Reconstruction has to reproduce the conditions that matter or it will be excluded, and Chapter 16 covers admissibility. Those conditions are marker make and model, propellant type, ambient temperature, paint mass and diameter, barrel bore, standoff distance, and impact angle. Establish each from evidence before you test, and where you cannot, test across a range and report the range.

Film everything, including the failures and the setup. A continuous take with no cuts around the critical moment is worth more than a polished edit, because the first question on cross will be what happened between the shots you showed.

Showing the Jury

Twelve and a half joules is a number the jury will not carry into deliberation. An egg exploding at the distance the child was standing is a thing they cannot put down. That is how you hand a physical quantity to people who do not work in physical quantities, and building one well has rules.

Why the demonstration beats the number

A juror has no reference for twelve joules the way she has one for a mile or a pound. The demonstration substitutes a reference she already has, because everyone has handled an apple and an egg. She is measuring an unfamiliar quantity against a familiar one, which is how people learn sizes. Sound does work no number does, and the demonstration authenticates itself: the jury watched it happen, so the expert's credibility is no longer what they are weighing.

What each object teaches

Table 16.1 The four objects and the physics each one carries

Two additional witness media are worth adding if the case supports them. Ballistic gelatin at a standard preparation gives a quantified penetration depth and is familiar to courts from firearms cases. A thin walled fluid filled sphere, documented for its mechanical likeness to a globe, is closer to the real anatomy. If you use one, be ready to state its wall thickness, its internal pressure, and why you picked it, and do not call anything an eye simulant unless you can support that.

Building one that survives a challenge

Demonstrative evidence divides into two categories that courts treat differently, and confusing them is how these get excluded.

An illustrative demonstration shows a principle without purporting to recreate the event. Requirements are modest: it must be a fair depiction of the principle, it must not mislead, and the witness must explain what it does and does not show.

A reenactment or experiment purports to show what happened, and it must be conducted under conditions substantially similar to the actual event. Dissimilarities that could affect the result are grounds for exclusion, and the proponent carries that burden.

The apple, egg, orange, and plate demonstration works best as the first kind. It shows the destructive power of this marker at this distance and does not purport to show what happened to the plaintiff's eye. Say that on the record, in those words, and the substantial similarity burden drops away while the persuasive force does not.

Where substantial similarity applies, control and document every variable: marker make, model, and revision; propellant type; ambient temperature; muzzle velocity, chronographed on camera immediately before; paint mass, diameter, and lot; barrel bore; measured standoff distance; and impact angle. My trial script establishes the distance out loud, and that sentence does legal work: "I've lined up a few items, all at about the same distance from this gun as Nathan was from Hendricks."

The framework for admitting expert testimony asks five things. Can the method be tested, and has it been. Has it been peer reviewed. Are error rates known. Do standards control how it is run. Is it generally accepted. A demonstration built on measured velocity, measured distance, and documented equipment answers the first and third. Do not overclaim the rest.

What to film, and how

Two cameras minimum. One wide, showing the marker, the operator, the target, and the measured distance in a single continuous frame. One close on the target at a high frame rate, because impact at ninety meters per second is invisible at normal frame rates and the slow motion replay is the exhibit.

Put the measurement in the frame. A tape measure laid on the ground from muzzle to target, readable on camera, is worth more than a paragraph in the report. Chronograph on camera immediately before, with the display readable.

No cuts around the critical moment. The wide camera runs continuously from before the marker is picked up to after the impact. For the residual gas demonstration in Chapter 10 that is not optional, because the whole point is that the bottle came off and stayed off. A cut anywhere in that sequence is the entire cross examination.

Film the failures, keep them, and produce everything. An expert who produces twelve takes including the ones that did not work is credible in a way that one polished take is not.

Narrate flatly. My script says what the objects are, states the distance, and lets the impacts work: "You can see and hear the destructive power." The jury is already reacting, and telling them how to react suggests the images cannot do it alone.

The one demonstration nobody expects

The strongest exhibit in a residual gas case is not the apple. It is the sequence from Chapter 10 performed live: bottle attached, normal shot, bottle unscrewed and set on the table, wait, load a ball, fire. Then the negative control: dry fire until it stops, verify zero, load, pull the trigger, nothing.

That sequence proves the defect, proves the defendant's mental model was reasonable and wrong, and shows the thirty second procedure that would have prevented the injury.

Product Liability

A paintball marker that fires after its owner removed the visible energy source is a product case, not just a supervision case. The residual gas fact pattern supports design defect and failure to warn at the same time, and American Society for Testing and Materials standard F2272 frames both by naming literature, packaging, design, and disabling devices in one requirement.

The three theories, and which one your facts are

Product liability recognizes three defect types, and they are not interchangeable.

Manufacturing defect. This unit departed from the manufacturer's own design specification. Liability is strict and the comparison is the product against its own blueprint: a failed valve seal, an out of specification spring, a cracked regulator body, or a lens that missed the specification the rest of the run met. It is the least common theory here and the easiest to prove when it fits.

Design defect. Every unit built to this design carries the hazard. Two tests are used, and jurisdictions divide between them.

Failure to warn. The product carried a non obvious risk and the manufacturer failed to give an adequate warning or instructions to a foreseeable user.

Consumer expectations and risk utility

Under the consumer expectations test, a product is defective if it is more dangerous than an ordinary consumer would expect when using it in a reasonably foreseeable manner. The test looks at the ordinary consumer's expectation, not at engineering feasibility.

The residual gas defect is close to a textbook consumer expectations case. An ordinary consumer removes the visible energy source and expects an inert object. That expectation is not naive: it is the model taught in firearms safety instruction and correct for every other projectile weapon he has encountered, and the product gives no external indication that it does not apply here. A product that silently defeats a correct and universally taught safety model is more dangerous than an ordinary consumer would expect.

Under the risk utility test, a design is defective if the foreseeable risks could have been reduced by a reasonable alternative design, and the failure to adopt it made the product not reasonably safe. Courts weigh the likelihood and gravity of harm, the feasibility and cost of the alternative, what the alternative does to utility and price, and whether the user could have avoided the danger by being careful.

Table 17.1 Risk utility factors applied to the residual gas defect

The last row is where these cases are won. Risk utility asks whether the user could have protected himself by being careful. Here, being careful produced the injury.

Failure to warn, and adequacy

A warning has to reach the foreseeable user, be prominent enough to be seen, name the specific hazard rather than a generality, state the consequence, and tell the user what to do instead. A warning that says "read the manual" is not a warning about anything.

The Forresthill marker's packaging carried a warning printed larger than the product name, which helps the plaintiff against the host because it establishes that the danger was disclosed to whoever opened the box. Whether it helps the manufacturer depends on what it said. A general warning that the product is dangerous and requires adult supervision is not a warning about residual gas, and a defendant gets no credit for warning about a different hazard.

Warning on the box versus warning in the manual

Placement is a separate adequacy question from content, and it decides more of these cases than content does.

Three facts about paintball markers make manual placement inadequate for this hazard. Markers routinely change hands, and one that reaches a church youth event has usually been sold, lent, or inherited without the carton and without the manual. Manuals are discarded within days of purchase. And the hazard presents at a specific moment, when the user removes the bottle intending to make the marker safe, typically months or years after any manual was read.

Those facts point to a permanent warning on the marker body where the hazard presents. Mold or engrave it next to the air source adapter: pressure remains after the bottle is removed, and the marker must be fired until it stops. That reaches every user for the life of the object, and its feasibility is established by every other permanent marking already molded into the same housing.

F2272 supports this reading. It mandates appropriate literature, packaging, design, and disabling devices, four elements listed conjunctively. A manufacturer that put a line in the literature and nothing on the packaging, nothing in the design, and nothing in the way of a disabling device has satisfied one of four.

Post sale duty to warn

A manufacturer that learns of a hazard after sale may have a duty to warn purchasers. The mainstream formulation asks four questions. Does the seller know or should it know of a substantial risk. Can those to be warned be identified, and are they likely unaware. Can a warning reach them and be acted on. Is the risk great enough to justify the burden.

The discovery this opens is the point. Ask for every complaint, claim, incident report, warranty return, technical service inquiry, and internal communication concerning discharge after removal of the air source. Demand the F2272 jolt test data and ask whether the test was ever run on an unbottled marker. Ask what the technical support line told callers who reported the behavior. Manufacturers maintain support operations that hold documentation for many legacy brands, and those records exist.

Sophisticated user and learned intermediary

A manufacturer will raise two doctrines, and both fit badly here.

The sophisticated user doctrine holds that a supplier may have no duty to warn a user who, by training, experience, or position, already knows or should know the hazard. It fits industrial and professional purchasers. A church volunteer, a scout leader, or a parent is not a sophisticated user of a pneumatic weapon, and neither is the marker's owner, because the whole point is that a person familiar with firearms applies the wrong model.

The learned intermediary doctrine allows a manufacturer to discharge its duty by warning a professional intermediary between it and the end user. It is principally a pharmaceutical doctrine, resting on a licensed prescriber with independent professional duties, and no one in the paintball chain resembles a prescriber. A big box retail clerk is not one. Chapter 18 develops what a retailer's duties actually are.

Where the case survey has to happen

Everything above is doctrine. It does not tell you how a jurisdiction has applied it to a paintball marker, whether any court has addressed residual discharge, what verdicts these cases produce, or which states use consumer expectations, risk utility, or both. That survey takes Westlaw, Lexis, or a paid verdict reporter, and it is the first item in the verification punch list.

Retailer Liability

Paintball markers and airsoft guns are sold in national sporting goods chains, next to bicycles and camping stoves, to whoever walks up with money. The retailer is not a passive conduit. It picks what to stock, how to display it, who to sell it to, and what to say about it, and each of those decisions carries exposure.

Tiffany M. Worth v. Academy Sports was a loss of eye case in Mississippi against a national sporting goods retailer, in which I served as the plaintiff's expert. I will not state facts about that case beyond what appears here, because I am writing from a case record entry rather than from the file. What the matter establishes is the category: the retailer is a viable defendant in a paintball eye loss case, and the theories below are the ones that reach it.

Strict liability reaches sellers in the chain

In most American jurisdictions strict product liability extends to any seller engaged in the business of selling the product, so a retailer that sells a defectively designed marker is exposed on the same defect theory as the manufacturer.

Many states have changed this by statute, in provisions commonly called innocent seller or sealed container statutes. They shield a retailer that only sold a sealed product, unless the retailer controlled the design, made its own representation, altered the product, or the manufacturer is insolvent or beyond the court's reach. Check the venue's statute and its exceptions carefully, because the exceptions are where these cases live.

Negligent entrustment

Negligent entrustment reaches anyone who hands a dangerous thing to a person he knows, or has reason to know, is likely to use it in a way that puts others at unreasonable risk. Youth, inexperience, and condition all count. The usual formulation has four elements: the defendant supplied the item; the recipient was incompetent, inexperienced, or reckless in a way that mattered; the defendant knew or should have known that; and the entrustment was a proximate cause of the injury. Applied to a retail sale, those elements become questions of fact you can develop.

• Was the purchaser visibly a minor, and did the clerk look.
• Did the store have an age policy, and was it written, posted, and trained.
• Did the point of sale system prompt for an age check, and does the transaction log show one.
• Did the purchaser say who the marker was for.
• Was the marker sold as part of a package that included eye protection, or without any.
• Did the store sell propellant, paint, and the marker together to the same person.

Negligent entrustment also reaches non retail defendants, often harder. The adult who handed a marker to a thirteen year old at a church event is an entrustor, and so is the parent who bought it for him.

Sale to a minor, and state age statutes

Where a statute prohibits sale or possession by age, violation supplies a standard of care that does not have to be argued from custom. Some jurisdictions treat an unexcused violation as negligence per se, others as evidence of negligence. Either way the statute must protect the class of person injured against the type of harm that happened, and an age restriction on air powered weapons applied to a child injured by one fits squarely.

New York Penal Law section 265.05 provides: "It shall be unlawful for any person under the age of sixteen to possess any air-gun, spring-gun or other instrument or weapon in which the propelling force is a spring or air." Violation results in adjudication as a juvenile delinquent, and the statute reaches both paintball markers and airsoft guns. In New York it is a direct negligent entrustment predicate, because anyone who hands such a weapon to a person under sixteen has handed over a thing that person cannot lawfully possess.

15 United States Code section 5001 preempts inconsistent state marking laws while leaving states free to bar sales to minors. Marking is federal. Age is state.

The imitation weapon statutes

Several states regulate objects that look like firearms, independent of what they shoot. These statutes matter in airsoft cases and in paintball cases where the marker is styled as a military replica.

New York General Business Law Article 39-B governs imitation weapons. Section 871 defines an imitation weapon as "any device or object made of plastic, wood, metal or any other material which substantially duplicates or can reasonably be perceived to be an actual firearm, air rifle, pellet gun, or 'B-B' gun," with exclusions for items that are brightly colored, transparent, or closed barrel and identified by the manufacturer without a laser attachment. Section 872 provides that "No person, firm, corporation or agent or employee thereof shall import, manufacture, sell, hold for sale or distribute within the state any imitation weapon," excepting interstate transport and lawful theatrical productions in film, television, and on stage.

Productions lawfully use replica weapons in New York under section 872's carve out, which is a different legal posture from retail sale to the public.

California Penal Code section 20170 provides that "No person may openly display or expose any imitation firearm in a public place."

Do not confuse these statutes with the federal marking rule. Section 5001 requires an orange muzzle marking of one quarter inch or longer on covered products and expressly excludes "traditional B-B, paint ball, or pellet-firing air guns that expel a projectile through the force of air pressure." A paintball marker is exempt by name. Chapter 4 explains why the application of section 5001 to airsoft is an open question.

What else a retailer does that creates exposure

Display and marketing. A marker displayed in the toy section, or in a way that signals it is a toy, is a representation. Photograph the display and get the planogram, the retailer's own diagram of what goes on which shelf.

Bundling. A starter package with a marker, propellant, and paint but no eye protection is the retailer's decision about what a customer needs, and so is a package with eyewear not certified to F1776.

Assembly and service. A retailer that fills bottles, mounts barrels, or assembles markers has handled the product and may lose the protection of a sealed container statute.

Employee statements. A clerk who tells a customer that a marker is safe for a young child, or that removing the bottle makes it safe, has made a representation the retailer may own.

Premises Liability and Supervision

The host who put the game in his yard is exposed on two independent tracks. One runs through the land: a possessor of property owes duties to those who come onto it, graded by the visitor's status. The other runs through the activity: a person who undertakes to supervise children owes a duty of reasonable care in doing so, whoever owns the ground. Chapters 20 and 21 build on this and do not restate it.

The status categories, and why the bystander is not a trespasser

An invitee enters for a purpose connected with the possessor's business, or onto land held open to the public, and is owed reasonable care, including inspection for hazards the possessor should find. A paying customer at a commercial field is an invitee.

A licensee enters with permission for his own purposes, the social guest being the classic example, and is owed a warning about known dangers that are not obvious to him. A child attending a church youth event is at minimum a licensee, and a strong argument makes him an invitee where the organization held the event open and derived a benefit from attendance.

A trespasser enters without permission and is generally owed only a duty to refrain from willful or wanton injury, subject to significant exceptions for children.

Many jurisdictions have collapsed the invitee and licensee distinction into a single reasonable care standard. Check the venue.

In a bystander case none of this is close. The five year old at Forresthill was on the property with permission, at an event the hosts organized and invited people to. He was not a trespasser. He was owed reasonable care, and the analysis moves immediately to what reasonable care required.

Two duties, and the one that actually decides these cases

Premises liability distinguishes conditions of the land from activities conducted on it. A hole in the yard is a condition. A paintball game is an activity, and for activities the possessor owes a duty of reasonable care in conducting it toward entrants he knows or should know are present.

The defense will want to talk about the yard, which was unremarkable. The plaintiff wants to talk about the activity, which was a projectile weapon game conducted among unprotected people. The yard did not injure anyone. The activity did.

Where children are foreseeably present, the reasonable care analysis accounts for children not appreciating risk the way adults do and not staying where they are put. A five year old wandering toward a game his brother is playing is not an intervening cause. It is the most foreseeable thing at the event.

Negligent supervision of minors

One who undertakes to supervise children owes a duty of reasonable care, measured by the risk of the activity and the ages of the children. The duty attaches to the undertaking, so an organization that gathers other people's children has undertaken their supervision whether or not it says so in writing. Two failures show up in these cases and should be pleaded separately.

Negligent supervision of the activity. Nobody enforced the rules while the game was running. Chapter 12 supplies the elements of adequate supervision and the documentary trail that proves its absence.

Negligent selection of the activity. This one is prior in time and often stronger. The decision to run a projectile weapon game for teenagers, in a yard, without netting, without a chronograph, without trained staff, and with small children present, was itself unreasonable. Even flawless supervision would not have made it safe. This framing survives the defense argument that a particular adult was watching at a particular moment, because it attacks the decision rather than the execution.

Where the host is an entity, negligent hiring, training, and retention theories reach it directly, independent of vicarious liability for a volunteer's conduct. Ask what training the entity gave, what approval process existed for a youth activity involving weapons, and who signed off.

Charitable and religious organization exposure

Charitable immunity was once a broad common law doctrine, and most American jurisdictions have abolished it or cut it back sharply. Where some form survives it is usually statutory, usually a cap rather than a bar, and often does not reach activities outside the charitable purpose or conduct worse than ordinary negligence. Some states immunize volunteers individually while leaving the organization exposed. The federal volunteer protection framework generally protects individual volunteers, not the organizations they serve, and does not reach willful or criminal misconduct or gross negligence.

Check the venue's statute early, because it determines who you sue and for how much. Never assume a church defendant is immune.

Two other lines of inquiry belong in every religious or youth organization case. Ask what policy covered the event and whether the activity was disclosed to the carrier, because many general liability policies for religious organizations exclude weapons activities, and a host who ran an undisclosed excluded activity has a coverage problem that shapes the negotiation. Then ask for internal policy. Denominational bodies, scouting organizations, and youth ministry associations publish written activity guidelines, and some prohibit paintball or require specific conditions. A written internal policy the local host violated is the standard of care handed to you by the defendant's own organization.

Waivers, Releases, and Minors

Commercial paintball fields run on waivers. Backyard events do not have them, and the absence is one of the easiest facts to establish in the case. Where a waiver exists and a parent signed it for a child, whether it holds up is one of the most split questions in American tort law. Do not assume the answer either way.

Why an adult's release is enforced and a parent's often is not

An adult who signs a release for his own participation is generally held to it, subject to the limits below, because he is contracting about his own rights and courts respect that choice in recreational settings.

A parental pre injury release is different, because the parent is contracting away someone else's claim, and two principles collide. Parents have a recognized right to direct their children's upbringing. The state also protects a minor's legal claims, which is why settling a minor's claim requires court approval in most jurisdictions and why a minor may generally disaffirm a contract.

Jurisdictions have gone different directions. A substantial group of states hold parental pre injury releases unenforceable as against public policy, reasoning that a parent has no authority to waive a child's cause of action before it exists. Others enforce them, at least for recreational activities, some by common law and some by statute enacted after a decision refusing enforcement. Several distinguish by defendant type, treating releases for nonprofit, school, or community activities differently from commercial operators. A few take intermediate positions turning on the nature of the activity or on whether the release was a condition of participation.

Determine which rule your venue follows before writing anything about the waiver. The split is genuine, it moves, and it is the second item in the verification punch list.

What kills a release even where they are enforceable

A release survives only if it clears every one of these.

Table 20.1 Grounds on which a release fails

The gross negligence carve out is the one that matters here

Nearly every jurisdiction that enforces recreational releases refuses to enforce them against gross negligence, recklessness, or willful and wanton conduct. Definitions vary, but the common core is an extreme departure from ordinary care or conscious disregard of a known risk.

Plead the facts that support it rather than the label. A host ran a projectile weapon game with no eye protection requirement, no velocity control, no barrel blocking devices, no boundary, and small children in the field of fire, after the packaging told him adult supervision was required. The seven failures from Chapter 1 are, collectively, the gross negligence pleading.

A waiver signed by nobody is the easiest fact in the case

In backyard cases there is usually no document at all, and the absence proves three affirmative things. Nobody counted who was present, so the host cannot say who was on the property or how many. Nobody was told anything in writing, so no warning was communicated in a provable form. And the host was not operating within the industry framework, because every commercial field uses waivers and the practice is a condition of insurance.

The same reasoning applies to the permission slip. Ask what parents were told the activity would be. In many of these cases they were told their children were going to a church event and never told it involved projectile weapons, which defeats any argument that they consented to the risk.

Assumption of Risk and the Bystander

Assumption of risk is the defense that ends sports injury cases, and it is the first thing raised in every paintball claim. It should not survive a bystander case, for structural reasons rather than sympathetic ones. Stated loosely it sounds like special pleading, so state it precisely.

The doctrine, stated correctly

Assumption of risk is "a common law doctrine that refers to a plaintiff's inability to recover for the tortious actions of a negligent party in scenarios where the plaintiff voluntarily accepted the risk of those actions." It divides in two, and the two branches operate on different elements of the tort.

Primary assumption of risk means "the defendant had no duty of due care to the plaintiff at all, and, as such, they cannot be found negligent." It is a no duty rule rather than a defense that reduces recovery, so the prima facie case never forms. Sporting events are the paradigm application.

Secondary assumption of risk arises "when a defendant does have a duty of due care to the plaintiff and that duty was breached." Duty and breach exist, and the plaintiff's own knowing encounter with the risk is weighed under comparative negligence, reducing recovery rather than barring it. Comparative fault has swallowed most of the defense, and Oregon abolished it by statute at Oregon Revised Statutes 31.620.

Why primary assumption of risk exists at all

The reason for the rule is what excludes the bystander, so say the reason out loud. A defender who plays hard will sometimes collide with a receiver, and if ordinary negligence law applied to that collision the sport would be litigated out of existence. So between co-participants no duty of ordinary care runs for the risks built into the sport, because the plaintiff by playing accepted a relationship in which those risks are distributed differently. Two conditions do that work: the parties are co-participants in a shared activity, and the risk is inherent, meaning it cannot be eliminated without altering the sport's fundamental nature.

The bystander satisfies neither condition

A bystander is not a co-participant. He did not enter the activity, accept its rules, or place himself in the relationship the doctrine presupposes. There is no reciprocity: he cannot shoot anyone, cannot be hit lawfully under the rules, and gets no benefit from the risk distribution the doctrine creates. Primary assumption of risk allocates risk among people who agreed to share it.

Being shot while standing outside a game is also not a risk inherent in paintball. It is a risk of paintball conducted without boundaries, supervision, or spectator separation, and removing it does not change the sport. Every commercial field in the country has removed it, with netting and a spectator line, and paintball is still paintball. Neither condition is met, so primary assumption of risk does not reach the claim, no duty is extinguished, and ordinary negligence governs.

Table 21.1 Participant compared to bystander under primary assumption of risk

Three fallback arguments the defense will run

He was present and could see the game. Presence is not participation. If mere presence triggered a no duty rule, every spectator at every sporting event would sit outside the protection of negligence law, which is not the law. Presence bears at most on secondary assumption of risk, which goes to a jury under comparative fault, and even that requires actual knowledge and appreciation of the specific risk.

He was a child, so his parent's consent binds him. A parent's consent to attend an event is not consent to be shot at it, and Chapter 20 covers what a parent can and cannot waive. A five year old also cannot appreciate a risk as a matter of capacity, so the doctrine's voluntariness requirement fails on its own terms.

The risk was obvious. Obviousness is a different doctrine, and even where an obvious danger reduces a duty to warn, it does not eliminate the duty to conduct a dangerous activity with reasonable care. The specific hazard here was not obvious to anyone, including the marker's owner, who removed the bottle believing that made it safe. A risk the shooter did not appreciate cannot have been obvious to a five year old.

Even for a participant, the defense reaches only inherent risks

Where your plaintiff was playing, primary assumption of risk still covers only risks inherent in the sport, not risks the defendant created by failing to do what every operator does.

Being shot during play is inherent. Being shot by a marker running at 350 feet per second because nobody owned a chronograph is not, since velocity control is universal and eliminating over-velocity does not change the sport. Neither is being shot after a game ends because barrel blocking devices came off inside the playing area, or being shot by a marker that discharged after its bottle was removed, which is a product defect rather than a feature of paintball. A mask that fails the applicable specification presents no inherent risk at all.

The organizing question is the same each time: could this hazard be eliminated without changing the fundamental nature of the sport? If yes, it is not inherent, and no duty was extinguished.

None of this can be cited from this book. The formulations above are black letter. How your jurisdiction applies primary assumption of risk to recreational shooting, and whether any court has addressed a bystander in this setting, requires the case survey in the verification punch list.

Damages for a Lost Eye

An eye is not a paired organ in the way a jury assumes. Losing one does not leave a person with half of normal vision. It leaves him with one eye, no stereopsis, a permanently narrower visual field, a lifetime of prosthetic maintenance, and a small but real chance of losing the other eye to an immune process set off by the first injury. In a child, all of it compounds across seventy years.

What happens to the eye, and what it costs to maintain

Where the globe cannot be saved, enucleation removes the entire globe, severing the optic nerve and extraocular muscles, which are reattached to an orbital implant, and evisceration removes the contents and leaves the scleral shell with an implant inside it.

The prosthesis is not a glass eye that lasts a lifetime. It is a custom painted acrylic shell fitted over the implant, requiring periodic professional polishing, refitting as the orbit changes, and replacement on a recurring schedule. In a child every interval is compressed, because the orbit is still growing and the socket must be expanded with conformers to allow normal facial bone development.

Complications belong in the life care plan because they are foreseeable, not speculative: implant exposure or extrusion, socket contracture, chronic discharge and inflammation, ptosis of the lid, and the sunken look that develops as orbital fat wastes away.

What monocular vision actually forecloses

Show the functional loss rather than asserting it. A jury with two eyes cannot imagine it.

Stereopsis. Depth perception from binocular disparity is gone permanently. Monocular cues remain, including motion parallax, relative size, and occlusion, and people adapt over months to years, but fine depth judgment at close range does not come back. Threading a needle, pouring into a glass, catching a thrown object, and judging closing distance are all affected.

Visual field. The horizontal field narrows by roughly a quarter on the side of the missing eye. That permanent blind sector makes the injury a mobility and safety problem, not only an acuity problem.

The remaining eye becomes a single point of failure. Every later risk to that eye now carries consequences it would not otherwise carry, which changes what the person can safely do, and what he has to wear, for life.

Vocational foreclosure follows. Occupations with binocular vision or field standards, work at height, work around moving machinery, and jobs requiring a commercial driving credential may be closed or restricted. Get the standard for the specific occupation from the licensing body rather than generalizing, because a vocational expert will be cross examined on the exact language.

For a child the analysis is harder and more valuable, because there is no work history. The forecast is built from family educational and occupational background, academic performance, expressed aptitudes, and earnings data for the relevant education levels. State the loss as a narrowing of the occupations open to him, not as one job he will never hold.

Disfigurement, and the parts nobody itemizes

A modern prosthesis can look very good and still not move like a natural eye. The asymmetry shows in conversation and in photographs, and for a child it plays out across every school year. Three categories get left out of workups and should not be.

The injury and treatment experience. The initial pain, emergency surgery, and the period of uncertainty about whether the eye could be saved.

Ongoing anxiety about the remaining eye. Realistic, medically grounded, and permanent. It changes behavior around every activity for life.

Family impact. Parental care, appointments, and the derivative claims available in the jurisdiction.

The life care plan

Build it from a treating and consulting physician's recommendations, not a template. At a minimum it covers prosthesis replacement across the life expectancy; professional polishing and refitting; ocularist and ophthalmologist visits; conformer management and socket expansion during growth in a pediatric case; treatment for foreseeable complications, including implant exposure and socket contracture; monitoring of the remaining eye, including whatever sympathetic ophthalmia surveillance the treating physician recommends; protective eyewear for life, replaced on a schedule; and psychological support where indicated.

Each line needs a frequency, unit cost, and duration, sourced to the treating provider or a published cost basis, then reduced to present value by an economist. A life care plan without a source for each line is an exhibit built to be dismantled.

The prognosis evidence is already published

The outcome data in Chapter 14 belongs in the damages case as much as the liability case. Four independent series put roughly half of paintball eye injuries at final visual acuity of 20/200 or worse. Alliman found 22 percent of injured eyes enucleated and 81 percent requiring surgery. Amin's drive-by series found 30 percent with ruptured globes requiring repair, 15 percent undergoing evisceration, and no light perception at last follow up in five of twenty patients. Dockery put paintball at a mean final acuity of 20/500, worse than every other shooting sport studied. Those numbers show the outcome is what the mechanism produces, which kills the argument that this result was unusually severe and therefore unforeseeable.

Glossary

Every term introduced in this book

Sources by chapter

Chapter 1

• Steve Wolf, narration script, plaintiff's demonstrative video, Ernst v. Church, Sacramento, California. Primary source, author's own trial demonstrative.

Chapters 2, 3, 8, and 9, equipment and ballistics

• Paintball marker. Caliber, velocity limits, propellant behavior, bore match.
• Paintball. Field practice, mask requirements, minimum engagement distance, chronographing.
• Paintball equipment. Barrel plugs, barrel socks, mask lens design velocity, fogging hazard.
• Ballistic chronograph. Optical, Doppler radar, and magnetic sensing principles.
• Energy and momentum values in Tables 3.1 and Figure 4.1 are the author's own calculation from one half m v squared, except the published 1.138 joule airsoft figure.

Chapter 4, airsoft

• Airsoft. Pellet dimensions and weights, velocity by game type, national joule limits, orange tip, state restrictions.
• 15 United States Code section 5001. Orange muzzle marking, the paintball exemption, preemption of state marking laws.
• 15 Code of Federal Regulations Part 272. Reserved, no regulatory text.
• ASTM F2999-19. Adult jewelry, confirming it is not the airsoft standard.

Chapter 5, ocular injury biomechanics

• Kennedy EA, Ng TP, McNally C, Stitzel JD, Duma SM. Stapp Car Crash Journal. 2006 Nov;50:651-71.
• Duma SM, Ng TP, Kennedy EA, Stitzel JD, Herring IP, Kuhn F. Journal of Trauma. 2005 Oct;59(4):960-4.
• Weaver AA, Kennedy EA, Duma SM, Stitzel JD. Journal of Biomechanical Engineering. 2011 Mar;133(3):031002.
• Marshall JW, Dahlstrom DB, Powley KD. American Journal of Forensic Medicine and Pathology. 2011 Jun;32(2):100-3.
• Kennedy EA and colleagues. Stapp Car Crash Journal. 2007 Oct;51:381-400.
• Duma SM, Bisplinghoff JA, Senge DM, McNally C, Alphonse VD. Current Eye Research. 2012 Jan;37(1):43-9.
• Takahashi R and colleagues. Clinical Ophthalmology. 2020;14:1445-1450. PMID 32546952.

Chapters 6 and 7, standards

• ASTM F1776-26, eye, face, and head protective devices for paintball sports.
• ASTM F2272-26, paintball markers.
• ASTM F2041-00, paintball marker warnings, withdrawn 2008.
• ASTM F2879, eye protective devices for airsoft sports.
• ANSI/ISEA Z87.1-2020, occupational and educational eye and face protection.
• ASTM Subcommittee F08.24 jurisdiction. Confirms no barrel blocking device standard.

Chapter 14, epidemiology

• Conn JM, Annest JL, Gilchrist J, Ryan GW. Injuries from paintball game related activities in the United States, 1997-2001. Injury Prevention. 2004 Jun;10(3):139-43.
• Listman DA. Paintball injuries in children: more than meets the eye. Pediatrics. 2004 Jan;113(1 Pt 1):e15-8.
• Thach AB and colleagues. Ocular injuries from paintball pellets. Ophthalmology. 1999 Mar;106(3):533-7. PMID 10080210.
• Pahk PJ, Adelman RA. Graefe's Archive for Clinical and Experimental Ophthalmology. 2009 Apr;247(4):469-75. PMID 19034480.
• Alliman and colleagues, 2009. Full citation to be confirmed.
• Haring RS, Sheffield ID, Canner JK, Schneider EB. JAMA Ophthalmology. 2016 Dec 1;134(12):1382-1390.
• Jones M, Kistamgari S, Smith GA. Pediatrics. 2019 Dec;144(6):e20192739.
• Amin SV, Otti VE, Farooq AV, Shah HA. American Journal of Ophthalmology. 2022 Oct;242:139-143. PMID 35594916.
• Dockery DM and colleagues. Journal of Pediatric Ophthalmology and Strabismus. 2021;58(6):377-384. PMID 34228563.
• Kennedy EA, Ng TP, Duma SM. Biomedical Sciences Instrumentation. 2006;42:7-12. PMID 16817577.
• Khalaily S and colleagues. Journal of AAPOS. 2018 Apr;22(2):107-109. PMID 29412150.
• Bisplinghoff JA, Duma SM. Biomedical Sciences Instrumentation. 2009;45:107-12.
• American Academy of Ophthalmology eye health statistics. General figures only; no paintball specific position statement located.

Further reading, abstracts not retrieved

• Gray W, Sponsel WE, Scribbick FW and colleagues. Numerical modeling of paintball impact ocular trauma. Investigative Ophthalmology and Visual Science. 2011.
• Nemet AY and colleagues. Israel Medical Association Journal. 2016;18(1):27-31.
• Tseng VL, Linakis JG, Mello MJ, Greenberg PB. Patterns of ocular injury from paintball trauma. Eye. 2014.
• Patel V and colleagues. Seminars in Ophthalmology. 2023;38(4):333-337.
• Dentel A and colleagues. American Journal of Ophthalmology. 2024 Sep;265:73-79.
• Fineman MS. Current Opinion in Ophthalmology. 2001;12(3):186-90.
• Kruger LP, Acton JK. South African Medical Journal. 1999.
• Veenstra M and colleagues. Journal of Trauma and Acute Care Surgery. 2015;78(6):1138-42.
• Ghazanfari-Nasrabad M and colleagues. Journal of Forensic Sciences. 2016.

Chapters 17 through 22, law

• Assumption of risk, Legal Information Institute. Primary and secondary branches, absorption into comparative fault, Oregon Revised Statutes 31.620.
• New York Penal Law section 265.05. Possession of air guns by persons under sixteen.
• New York General Business Law section 871. Definition of imitation weapon.
• New York General Business Law section 872. Prohibition on sale, with theatrical exemption.
• California Penal Code section 20170. Public display of imitation firearms.
• All other doctrine in Part Six is stated from black letter principles without citation. See the verification punch list.

Verification punch list before publication

Everything below still needs a primary source or a paid research tool. This list is a feature of the book. It is what separates a reference you can rely on from one that reads well and gets a witness impeached.

Open items, with where to get each

About the author

Steve Wolf is an expert witness in firearms, pyrotechnics, stunts, fire, on-set safety, wildfire, theatrical rigging, diving, and explosion cases. He has spent his career in production, building, firing, rigging, and detonating the systems he now testifies about. He founded RangeMaster, Tactical Choices, Wolf Stuntworks, Pyro School, Team Wildfire, Wildfire Labs, Stunt Ranch, and Science in the Movies. He is a patented inventor of fire suppression technology, with patents in applied physics, fluid dynamics, thermodynamics, and combustion engineering, and holds certifications in emergency management, incident command, active shooter response, wildfire management, and mass casualty response. He is a Columbia University graduate, retained by attorneys nationwide, on both sides, in civil and criminal matters.

On this subject specifically: he owns and operates a paintball park in Austin, Texas. He holds a Class 1 Federal Firearms License, is a National Rifle Association and state certified firearms instructor and a certified firearms instructor trainer, and runs a state licensed summer camp. He has been retained as the plaintiff's expert in paintball eye loss cases, including Ernst v. Church in Sacramento, California, arising from the July 2007 Forresthill incident, and Tiffany M. Worth v. Academy Sports in Mississippi, against a national sporting goods retailer.

Available to attorneys nationwide. SteveWolfExpertWitness.com