What is Airsoft?

Airsoft is a military simulation sport somewhat similar in nature to paintball, in which players participate in mock combat with authentic military-style weapons and tactics. Unlike paintball, which uses paint-balls as projectiles, Airsoft guns usually use 6 mm spherical projectile (pellet) made typically with injection-moulded ABS plastic. The 'weapons used in Airsoft are generally exact full size replicas of military weapons such as the Colt M16, H&K MP5.

The sport is extremely popular in eastern Asia, Japan, Taiwan, and Hong Kong, where real arms are difficult or impossible to obtain because of local laws. For this reason the vast majority of airsoft guns, accessories, and aftermarket upgrade parts are made in Japan, Taiwan, Hong Kong, and Korea. Airsoft has been since made illegal in most parts of Mainland China. There is currently a growing interest in the West again, especially in the United States, Great Britain, Germany, Spain, Italy, and Scandinavia, bolstered by an active and expanding Internet scene as well as easy access to equipment through secure online shopping from sites, such as Airsoft Adventure in the UK.

Airsoft
Early history:
Airsoft began in Japan during the mid-1970s where real guns are prohibited by Japanese law. It can trace it roots to 1:1 scale plastic model kits of popular real firearms. From that point on it went into three separate directions; air-driven pellet guns, cap-type guns, and pellets driven by a spring.

The guns which had bullets driven by a spring had a spring in each shell. The bullet was forced into the shell and held by a two small locks. Placing the loaded cartridge into the chamber, and firing the gun, would force the cartridge forward and releasing the locks on the bullet. The spring would propel the bullet forward. Pulling back the slide would cycle the next cartridge. The drawback with this design was that this bullet would have a maximum range of 20 feet (6 meters).

The cap-type guns used a powerful explosive cap to make the noise of the gun and in later versions, to actually eject the spent cartridge from the gun. More sophisticated versions included the MAC-11, and CAR15 with a fully loaded magazine, can fire fully automatic. These guns were good alternate movie-prop guns. But since these guns did only cycle the action and make a bang, the popularity of these cap-type guns never really caught on because no projectile was fired from it.

Early Japanese air-driven pellet guns had a soft plastic bullet shaped like a pointed mushroom, which was then inserted into a hollow cylindrical plastic shell, which approximated the sized of a real gun cartridge and had the look of one. These guns were based from semi-auto pistols, and the plastic cartridges were loaded into a magazine which was then inserted into the gun. The number of cartridges loaded into the magazine would be similar to a real firearm magazine. The gun was spring-powered normally by pushing the slide forward to strip the cartridge off of the magazine, loading it into the chamber to fire, and simultaneously cocking back the spring air piston. Pulling the trigger of the gun released the spring piston, the air went through the rear of the hollow cartridge and expelled the plastic pellet through the barrel. By continuing pulling back the trigger, the locking mechanism for the slide would release, the slide moving rearward and the empty plastic shell would be ejected. By repeating this process, another pellet can be fired until the magazine was empty.

Unfortunately, this process had some drawbacks. The shells were easy to lose, and the pellets were few and expensive. The next evolutionary design step was to replace the plastic bullet with a round BB (pellet). The shell was kept and the BB was inserted into the shell to make a cartridge. A rubber O-ring in the lip of the hollow shell held the BB in place. BBs were plentiful and easier to manufacture compared to the plastic pellet. Eventually, the plastic shell was removed from the design to evolve into the airsoft guns we know of today.

Airsoft in American culture began with several abortive attempts in the 1980s by the Daisy BB gun company of the USA to market a BB gun that could be safely shot by opposing players at each other. It was known then as 'Replisoft' and 'soft air,' a name which airsoft is still sometimes known by. These spring guns used the plastic shell and BB design. The products did not prove popular in the U.S. market. However the sport continued to prosper in Asia and gained significant popularity. Most modern airsoft technology developments were created in 20 years of expanding interest in Japan.

Growth in the West:
Starting with early 2003, Daisy has once again begun marketing airsoft guns for sale in the US, under their 'Powerstrike' brand name. This and other models have begun appearing en mass in major brick and mortar distributors, expanding what in the US was traditionally a generally Internet based operation. US-based manufacturers of tactical gear and equipment have also begun to recognize the sport, some marketing products specifically for use in airsoft. On the Internet, the online store Surplus and Adventure has set up a new secure online store called Airsoft Adventure, specially dedicated to Airsoft Guns and Accessories, with a vast range of quality equipment at affordable prices.

Airsoft guns
Modern airsoft weapons can be grouped into three general types by their operating mechanism:

Spring powered Airsoft Guns

Gas Powered Airsoft Guns

Automatic Electric Airsoft Guns

Spring powered Airsoft Guns:
These weapons fire a BB using a simple spring that must be cocked by hand prior to the shot. Most spring weapons are for indoor playing as they have limited range and cycle rates (because they must be hand operated). Typically, spring airsoft weapons are inexpensive compared to similar models in gas or electric format because they do not use any external power to assist in firing the BB. The most inexpensive and readily available of any of these are 'springer' pistols, which generally operate by compressing a small piston/spring assembly and simultaneously chambering a BB from the magazine by pulling back the slide every time before firing a shot. Therefore, you cannot shoot fully or semi automatic. Though these guns constitute the vast majority of airsoft guns, there is a large selection of mid-range spring powered rifle replicas on the market, and a handful of high-end precision bolt-action sniper rifles which employ manual cycling in order to drive extremely heavy springs (and hence produce higher muzzle velocities).

Since the airsoft spring pistols are inexpensive, they are suitable for beginners. However, spring guns in the form of rifles are normally not for beginners. A rifle shoots out a more powerful force, sometimes stronger than airsoft electric guns and gas airsoft guns. Some good airsoft sniper rifles also uses spring as the mechanism. The long barrels really boost the speed when firing a shot. Since snipers do not engage in a field combat, airsoft spring guns are suitable as snipers do not need to fire many rounds of shots.

Gas Powered Airsoft Guns:
These weapons fire BBs using HFC 134 gas or Green gas, also known as common propane, which is used in most guns with metal slides (upper receivers). In modern gas guns, this is usually a diflourothane or tetraflourthane gas, similar in composition to Freon. This is a liquid when inside its container, and remains in that state when injected into the magazine of an airsoft gun. When a valve on the top of the magazine is tripped, some of this liquid is ejected as a gas at high pressure and operates the specific cycling mechanism of the gas gun. Gas powered Airsoft Guns can typically be grouped into NBB (Non-Blow-Back) and GBB (Gas Blow-Back) categories. NBB guns do not feature a cycling bolt or slide while GBB guns have some sort of moving bolt that realistically chambers a BB from the magazine when cycled. Most NBB and GBB guns come in the form of pistols, with detachable magazines that contain both the BBs and the gas. Some rifles and machine gun replicas are gas operated as well, whether to take advantage of the realism afforded by bolt cycling or to allow adjustable muzzle velocities. The vast majority of all gas guns are produced in Japan and Taiwan. Modern airsoft guns typically can use both HFC134 and the more powerful green gas (propane) and HF22. It is usually recommended that the weaker HFC134 be used with Japanese guns and the stronger HF22 be used with Taiwanese models, for reasons of pellet velocity limitations and because Taiwanese models are now often equipped with metal slides rather than plastic (which is universal for Japanese guns), meaning that they can take the higher pressure and may not even cycle with lower-pressured gases.

Many older gas guns, now out of production, use CO2 or HPA nitrogen through an external tank and regulator. With the advent of electric guns, this system has become very rare, due to the high cost and instability of gas operation. But the level of quality in construction has prompted many current collectors and players to continue to favour these 'classic' airsoft guns.

Recently, players have begun to use propane as a power source, which produces similar results to Green Gas. Chemical composition of green gas has been suspected actually to be either propane or a fluoropropene. Additionally, new gas gun models have appeared that are powered by standard 12 g CO2 capsules, either on a regulated external rig or build into the magazine of the gun itself.

Gas guns generally require more maintenance than an AEG or spring gun. This is because of all the seals and valves required to hold the gas, and keep the gun from leaking. They need to be lubricated frequently to keep the seals from drying up and cracking. A small solution to this is that Green Gas (HF22) has silicon lubricant in it, therefore it keeps the gun lubricated while using it. Gas guns also have certain weather restrictions, they can be used in just about any weather, however the colder it is outside the less efficiency the gas will provide. Also operating the gun in the cold could cause the valves on the gun and or magazine to freeze and not be able to work until thawed out again. That is typically why gas guns work much better in warmer climates. In the long run, gas guns are also more expensive than buying a spring gun or AEG because you must continually buy more gas to power it, and lubricant to keep it working well. As opposed to AEG's which only require lubricant, and a battery which can be recharged many times.

Automatic Electric Airsoft Guns:
Also known as AEGs, these weapons are powered by batteries and an electric motor, which cycles an internal piston/spring assembly in order to launch the BB projectile. These are by far the most common Airsoft weapons in serious competition use today. These guns were originally developed in Japan, and the Japanese model giant Tokyo Marui dominates the market today with many quality models. In a Marui AEG, the motor drives a series of 3 gears mounted inside a gearbox. The gears then compress a piston assemble against a spring. Once the piston is released, the spring drives it forward through the cylinder to push a BB into the chamber, through the barrel, and forward from the muzzle. Many manufacturers have now more or less replicated this basic model, adding reinforced parts or minor improvements. But it remains the general design common to almost all modern AEGs (with the exception of the TOP machine gun line).

In recent years, challengers to Tokyo Marui from Taiwan and Hong Kong have begun producing AEGs as well, emphasizing primarily on inexpensive metal parts. Classic Army of Hong Kong and ICS of Taiwan, who both have had long experience producing aftermarket accessories and reinforced parts for Marui AEGs, first began with versions of the Heckler and Koch MP5, a model which Marui had produced for some time. Both versions boasted metal receivers and parts, with essentially the same internal design as their Marui predecessor. And both initially suffered from quality control issues which marred their brand name for several product generations. Currently, both companies have begun to branch out in different directions from Tokyo Marui. The ICS M4/CAR-97 carbine features an innovative swing-open gearbox and receiver and an anti-reversal latch disengage built into the forward assist button. The Classic Army CA33E replica of the HK33E is a rifle model which Marui does not produce at all. Quality control has appeared to have improved as well on current models for both brands.

Electric motors generations:

EG560 1st Generation Tokyo Marui Motor. No longer used, except for a specially tuned version in the FAMAS.

EG700 2nd Generation Tokyo Marui Motor. Standard in most guns

EG1000 3rd Generation Tokyo Marui Motor. Higher speed motor than the EG700 motor, but with slightly less torque. Widely accepted as the best stock motor.

Airsoft Gun parts and upgrades
After a while most players begin to think about upgrades and to improve their weapon. The first thought is probably to increase the pellet velocity to gain extra range. But the only weapons that need longer ranges are rifles such as sniper rifles and the real normal intention is to increase the durability and lifespan of the weapon. Most players settle for merely increasing the battery size and spring strength.

When an airsoft weapon is upgraded to increase pellet velocity, the weapons lifespan will decrease. The power of an airsoft weapon depends on three things: the strength of the spring that pushes the piston forward, the amount of air the piston compresses and the precision of the barrel. When a weapon is highly upgraded it becomes a specialised tool for serious airsoft skirmish and to dryfire (i.e. without pellets) puts an increased strain on the parts.

Always remember that upgrades can invalidate warranty.

Spring:
There are two ways to measure how strong a spring is compared to a standard spring. The Percentage system and the Meter Per Second system. A standard AEG has a pellet velocity of 90 m/s (100%) with a 0.20 g pellet. A M100 spring increases this velocity to 100 m/s. There are M100, M120, M130, M140, M150 and M160 springs. The percentage system is harder to use since it doesn't easily tell what the weapon will perform like. A very powerful spring requires that the entire gearbox is replaced.

Bearings & bushings:
The axles inside the gearbox are attached to the housing by small plastic bearings and these will eventually wear down. If these bearings are exchanged to metal bushings or even ball bearings, the lifespan of the mechbox will increase (almost double according to many players). Ball bearings allow higher rates of fire as well. Shims are thin metal washers added to the axles that make sure that the gears in the gearbox are precisely aligned.

Barrel:
A standard airsoft barrel often has an internal diameter of 6.12 mm. If this barrel is exchanged for a precision barrel with a 6.04 mm internal diameter the amount of air that slips by the pellet reduces and the benefits is that the pellet has less spread and about 5% to 10% extra velocity, depending on the barrel length. The downside is that the barrel clogs up more often when low quality pellets are used and has to be cleaned more often. A longer barrel increases range, but the barrel can't be too long since if the amount of air in the barrel is more than the amount of air the piston push forward, a vacuum will develop in the barrel and the pellet will be sucked back with a big speed reduction. There is a method called 'cratercutting' that has the effect that just before the pellet leaves the barrel the air slips by and cuts a hole in the wall of air that is formed in front of the barrel. This technique is normally used by players aiming to increase the range of the weapon.

Battery:
If a battery's voltage increases, so do the rounds per minute in an AEG motor. All standard AEG batteries are 8.4 volts and the only difference between the different sizes is that a large battery has a capacity of 1300 mA·h, while the other small standard batteries have capacity of 600 mA·h. This means that a large battery will last for about twice the amount of shots. Upgrades inside a gearbox often reduce the rate of fire and if you then use a battery with a higher voltage like 9.6 V or 10.8 V the rate of fire wont drop as much or even increase. A higher voltage also wears a motor down faster and more maintenance is required. It is possible to use 12 V to power an AEG but this isn't to recommend since the wear is increase very much, the contacts in the trigger is faster worn out and the overall lifespan is sharply reduced.

A battery with a higher capacity (more mA·h), will last longer on the field. An upgraded weapon also requires more current and the amount of shots that can be fired will decrease unless a bigger battery (more charge) is used. The usual battery is NiCd (nickel cadmium), but there is another type called NiMH (nickel metal hydride). The NiMH usually has a higher capacity (mA·h), but usually offer less current and can't drive the larger springs (i.e. M120). However if you do your research you will find 'high drain' NiMH batteries available as well. A 20 ampere or higher 'drain' is ample for most upgrades on an AEG, and 30 A will drive even the highest powered springs (M130+)

Gears:
The normal gears in a gearbox have an approximate lifespan of 30,000 shots, and a new set of gears will last longer since they are made from a material of greater strength. There are sets that increase the rate of fire but reduce the motor's power and there are also sets that reduce the rate of fire but increase the motor's power. The 'Helical Cut Gears' are a special set that grip better between the gears and don't break as easily as standard gears. The largest supplier of upgrade and replacement parts is Systema.

Nozzle:
A small plastic or metal nozzle seals the space between the air-piston and the BB pellet. This nozzle helps to maximize the air-flow fed from the cylinder to the barrel; therefore, reducing wasted air pressure and resulting in a slightly increased pellet velocity.

Motor:
Most upgrades reduce the rate of fire. By switching to a stronger motor the rate of fire isn't reduced as much. An upgraded AEG should have at least an EG700 motor. The strongest motor is EG1000. All new models that Tokyo Marui releases have EG1000 motors, but many of the older models have EG700 or even EG560. Not all AEG's can have a motor upgrade. If the original spring isn't replaced with one stronger than M120, the EG560 motor can take it. However, the battery will probably have to be changed to a 9.6 V or even 10.8 V.

Piston:
With stronger springs and tighter barrels, the physical strain on your piston and cylinder head increases. A piston can be equipped with a 'silent' or 'anti-vacuum' piston head. The silent piston head reduces the impact the piston makes in the cylinder and also reduces noise. The Anti-Vacuum piston head prevents the forming of a vacuum in the cylinder - this means that the barrel length can be extended without too much risk of the 'dreaded suck'.

Mechbox:
This is a totally new mechbox with new and better gears, stronger spring, nozzle and other improvements (see below). This isn't a cheap upgrade but the durability and lifespan increase and so do the pellet velocity and overall performance. A new mechbox isn't available to all models, like the FAMAS doesn't have an upgraded mechbox. There are different versions of mechboxes since they're used in different weapon models.

Quality control has appeared to have improved as well on current models for both brands.

Version 1 is only used in FAMAS

Version 2 is the most common and is used in M16, G3 and the MP5's

Version 3 is used in AK47, MP5K & MP5K PDW and Sig SG550, Steyr AUG, 551 and 552 seals

Version 4 is only used in the PSG-1 and is semi automatic

Version 5 is used in the UZI and has the recoil system

ersion 6 is used in M1A1 Thompson and the P90

Resuming, the Mechbox is a completely upgraded gear-box system, normally including:

Taper Spring

Spring guide

Air seal nozzle

Bore-up Cylinder set

Polycarbonate piston

All helical gear set super torque up

Oil-less metals

Cut Off lever

Selector plate

Tappet plate

Reversal stop latch

Stopper arm

Trigger

Switch Assembly

Reinforced anodised gearbox

Metal body:
Metal body upgrades are typically expensive, but the increased durability, weight and a more realistic appearance of the weapon are common reasons for upgrading to a metal body. Recently, many manufacturers such as Classic Army and ICS offer metal bodies as a stock feature on some of their products.

Metal Hop Up:
HopUp is the ability of a gun to put backspin on the BB as it leaves the barrel. This increases the distance the BB will follow a straight trajectory before the effects of wind resistance and gravity take over. This isn't equipped in all guns but is a purchasable upgrade.

BB's
The 6 mm BBs themselves are also produced in various masses. Typically 0.12 g and 0.2 g BBs are used for spring pistols; 0.2, 0.23, or 0.25 g for AEGs and gas pistols; and 0.29 g, 0.3 g, 0.36 g, and 0.43 g for sniper rifles. Steel BBs weighing up to 0.88 g can also be used for target shooting, though they are not common. Recently, airsoft guns in Japan have been produced that are chambered for 8 mm diameter pellets. For the most part, these new guns are replicas of large calibre pistols and revolvers, partially for the reason that a 6 mm pellet on these weapons (ranging from .357 magnum and beyond) would be unrealistically small. The 8 mm pellets and guns are still comparatively very rare.

There have also been products made which do shoot spherical BBs. The best known of these is the Asahi 'Blade Bullet' BB, which are now extremely difficult to find and quite expensive to buy. These were designed to be shot from the short-lived Asahi M700 and M40 premier grade rifles, which were produced in 1993. Compatibility with other airsoft guns is highly limited, especially due to their inability to be used with Hop-Up.

BBs made of paint are available but are incompatible with guns that have Hop-Up as they break in the gun. Paint is very unpopular with airsofters because it tends to stain gear and clothes. Players that wish to use paint should check that it is ok with their fellow playmates. Most people would suggest you play paintball if you want to use paint BBs.

Pellet weights and their usage:
0.12 g Used by some gas and spring weapons. High velocity and low stability

0.20 g Standard weight for most weapons. AEG uses these or slightly heavier pellets

0.25 g Heaviest weight for standard AEG, BlowBack and Spring guns

0.30 g Standard weight for most sniper rifles

0.36 g Heavier pellets for sniper rifles. Very slow but high stability

0.43 g For the highest level of upgrades in spring and gas sniper rifles

Metal-coated and steel BBs are also available, but to be used for target shooting only. Graphite coated BBs are often used by snipers.

There is also available biodegradable BBs (usually in 0.20 g and 0.25 g) and tracer BBs (usually in 0.15 g, 0.20 g and 0.25 g);

Note: A recent study has shown that while some BB's are biodegradable, it doesn't necessarily mean it is environmentally friendly.
The majority of 'bio' BB's degrade into something like styrofoam, which isn't biodegradable.

Less common weights:

0.22 g Western Arms BBs for their gas blowback pistol series

0.29 g Maruzen’s BBs for their APS series

Physics of Airsoft
Pellet velocity vs. energy vs. weight:
The pellet velocity of automatic electric guns is determined in large part by the tension of their main spring and so there tends to be a stratification of values. The most common airsoft velocity limits are between 300 to 400 ft/s (90 to 120 m/s) for AEGs and 400-500 ft/s (120-150 m/s) for single shot guns (sniper rifles). Here are some common levels of airsoft gun pellet velocity.

Unit equivalents

Pellet velocity 85 91 100 107 115 122 137 152 168 (m/s)
280 300 328 350 377 400 450 500 550 (ft/s)
Weight
0,12 g 0,44 0,50 0,60 0,68 0,79 0,89 1,13 1,39 1,69
0,20 g 0,73 0,84 1,00 1,14 1,32 1,49 1,88 2,32 2,81
0,25 g 0,91 1,05 1,25 1,42 1,65 1,86 2,35 2,90 3,51 (joules)
0,30 g 1,09 1,25 1,50 1,71 1,98 2,23 2,82 3,48 4,22
0,36 g 1,31 1,51 1,80 2,05 2,38 2,68 3,39 4,18 5,06
0,43 g 1,57 1,80 2,15 2,45 2,84 3,20 4,04 4,99 6,04
3,00 g 10,93 12,54 14,99

notes: 3.00 g is the typical weight for a paintball pellet. This weight is for comparison purposes only and is not used on Airsoft.
Higher energy but different collisions read Elastic collisions topic for further information.

1 m/s = 3.281 ft/s
1 ft/s = 0.3048 m/s
Performance:
For the sake of a relative uniform standard, the usual BB mass used when determining pellet velocity is 0.2 g. Airsoft guns shoot 0.2 g BBs at velocities from 100 ft/s (30 m/s) for a low-end spring pistol, to 550 ft/s (170 m/s) and beyond for heavily-upgraded customized sniper rifles. Most non-upgraded AEGs using the Tokyo Marui system are in the middle, producing velocities from 270 to 300 ft/s (80 to 90 m/s), but upgrades to the internal components can increase the pellet velocity significantly. Because of their low mass, these BBs have very little kinetic energy on impact compared to paintballs, ranging from 0.5 to more than 6 joules (J). A typical paintball at 300 ft/s (90 m/s) produces more than 12 J. This makes the sport arguably safer than paintball although protective gear, especially for the eyes, is considered a requisite for safe play.

The total kinetic energy of a body (muzzle) can be considered (for non-relativistic mechanics) as the sum of the body's translational kinetic energy and its angular kinetic energy (also known as rotational energy). It's normal to find airsoft - kinetic calculations using only translational kinetic energy to simplify formula use.

Hop-up (High Operation Power UP) - Bernoulli's principle:
Bernoulli's principle is a physical law that says that if a bullet is given a backspin an overpressure is formed under the bullet and an under pressure is formed on the top of the bullet. These pressures affect the bullet as on an airplanes wings a lift is formed. The bullet is sucked up. If the Bernoulli principle is equal to the effect of gravitation the bullet will fly longer and straight until the bullet loses its energy and the Bernoulli principle stops working.

A significant development that has since been incorporated into almost all good quality mainstream airsoft guns has been 'hop-up.' This is a simple rubber piece around the chamber or rear of the barrel that is thicker on the top in order to provide a backspin on the BB as it exits. Consistent with Bernoulli's principle, this causes air above the BB to move slightly faster than the air below it, creating a measure of lift. The practical effect of this mechanism is immediately visible and quite effective. Using it can extend the range of an airsoft gun by up to 50%. Some guns feature an adjustment mechanism to increase or decrease the amount of backspin, which allows fine tuning of the lift generate to accommodate various BB masses. Hop-up also means that certain BB masses will not shoot in a relatively straight trajectory from certain guns - the hop-up produces either too much lift (causing the BB to 'float' as it flies forward) or too little (causing a premature end to its flight). So in the words of a 12 year old airsofter this means it puts a spin on the BB to change the pressure on the top and bottom to create lift.

Safety
Storage and Transportation:
Basic rules for storing and transporting airsoft guns:

Unload the airsoft gun by removing the magazine and firing to a safe location until empty

Place the red cap on the barrel end (USA)

Place the gun inside a gun case (or container) that fully encloses it. It's not a good idea to use as a gun case the original card case that is shipped with airsoft guns

Render the gun inoperable by removing and storing the battery away from the gun

Make sure that the gun case is locked, tied or zipped in a way that will not open during transportation or while stored

Always lock all your airsoft gear in a safe place

This rules are just a basic set and does not refer to any country specific law, make sure to check in your area.

Pellet velocity limits:
All participants use ONLY Airsoft guns in their games. These guns must conform to the pellet velocity limit that your group or country has decided on. Some countries have legal limits on the power/pellet velocity of Airsoft guns so make sure to check in your area.

Also based on internet searches, here are some of the methods/criteria used by airsoft teams to establish limitations (i.e. maximum pellet velocity, minimum firing distance,...).

By gaming area/type (i.e. CQB, woodland)

By gun type (i.e. sniper, assault rifle, support)

By gun firing mechanism (i.e. AEG, GBB, Spring)

By measured pellet velocity (i.e. any gun firing above 500 ft/s (150 m/s) is a sniper class weapon)

By spring type (i.e. max. allowed spring is M120)

Some groups use more than one method/criteria’s to establish limitations. For example game area/type is often used with gun type.

Protection:
All participants MUST wear eye protection! Mouth protection is recommended. Ideally all Airsoft players should have full face masks, long sleeve shirts, full pants, and gloves whenever they play Airsoft. If you plan on playing at any professional paintball/airsoft locales then you will have to have a full face mask. This is for legal/insurance reasons and cannot be avoided. It's strongly recommended that anyone that continues to be a problem in terms of wearing eye protection during games be banned from playing with your group. Nobody wants to be responsible for shooting someone's eye out. If you need to clear your mask because of fogging or some similar problem then crouch/lay on the ground with your face as close as possible to the ground and quickly clean your goggles.

Regarding eye protection, all products of this kind should meet at least one of the following standards:

ANSI Z87.1

EN166 European Standard (This standard excludes protection against X-rays and lasers. EN166 F is for Low Energy Impact and EN166 B is for Medium Energy Impact)

ANSI Z80.3

Rules of the Game
BB hits:
If you are struck by an airsoft BB then you are hit and for purposes of the game are considered 'killed'. This means that you are out of the current game unless you are using special rules (see below). Most times when you are 'killed' in a game you have to go to a safe-zone where you wait for the next game to begin. Hits to your weapon do not kill you. If you think that you might have been hit but aren't sure then you ARE hit and you should call yourself out immediately. This eliminates silly arguments during a game. Whenever you are hit during a game you must announce loud and clear, 'HIT!' and then walk to the designated safe-zone with your weapon held high over your head with both hands. Be sure to keep your hands and weapon in the air so you aren't mistaken for a player that is still in the game. A player that repeatedly causes problems with calling himself out should not be allowed to play any more.

A Special Note: Eventually everyone is going to experience getting shot after they have called themselves out for a game. The #1 reason people get shot after they are out is because they don't readily identify themselves as being hit. If you don't want to get shot after you call out then be sure to do the following:

LOUDLY call out 'Hit!' or 'Dead!'

Immediately stand straight up (If you weren't already) and hold your weapon in a way that is clear to everyone that you are out of action. For example: holding gun above your head with both hands, or put gun in rest (holster or sling) and keeping hands away from any gun

Begin walking (not running) towards the designated safe zone ASAP. Use a clear path so that everyone can see you

If you follow these simple steps then you will greatly reduce (although not completely eliminate) getting shot after you call out

Another method that an airsofting club or event organiser can arrange is for the use of red rags. When a player is hit, he or she should then immediately pull out a red rag and wave it around, places it over his head, or otherwise display it. This indicates that this person is now dead. This method greatly reduces the number of arguments brought about by people getting shot after they have already been hit. Many airsoft organisations are now beginning to use this method, such as Mike Force Airsoft.

Communications:
Depending on the scenario size, different communications methods are used. For small scenarios the whistles signals are commonly used as follows:

Whistles signals:
1 whistle = start game

2 whistles = end game. All players stop shooting and head for the staging area
Normally a game ends in one of three ways, depending on the scenario.

The time limit for the game expires

Only one team or player remains

Scenario Objectives have been completed

3 whistles = pause game. All players stop shooting, put their guns down and stay where they are. This is the whistle signal normally used when a non-player has entered the field

Radio Communications:
For large scenarios, it's common to use radio communications. Not only used for starting/stopping games, but also for team, organization and emergency communications. Note that allowed radios services and communications regulations varies by location. Here is a short resume:

FRS (Family Radio Service)

is for use in the US and Canada

14 Channels (462.5625 ~ 467.7125 Mhz)

0.5 W ERP

~2 miles (3 Km) flat open area/ <0.6 miles (1 Km) urban areas

LPD (Low Power Device)

is for European use

69 Channels (433.075 ~ 434.775 Mhz)

10mW ERP

~1 mile (1.5 Km) flat open area

Note that LPD is in the middle of 70 cm ham radio band, which means you will be sharing frequencies with hams. Just remember that they can use 35W instead of 10mW

LPD (Low Power Device)

is for Japanese use, they call it 'Mini set'

20 Channels (422.0500 ~ 422.300 Mhz)

10mW ERP

~1 mile (1.5 Km) flat open area

PMR446 (Personal Mobile Radio) (also known as the European version of FRS

is for European use

8 Channels (446.00625 ~ 446.09375 Mhz)

0.5 W ERP

~2 miles (3 Km) in flat open area/ <0.6 miles (1 Km) urban areas

Although equipment has it's own functions, here is list for a desirable Airsoft communications system

Tough rugged construction and shock resistant

Ability to Work with either 'AA' alkaline batteries, rechargeable Ni-Cd battery or Ni-Mh batteries

External speaker and microphone connector

Earpiece with PTT or throat microphone

Silent alert for discreet operation (vibration system)

Illuminated LCD for night use

Battery indicato

Vox (voice activation) for hands free use

Scanning ability to find other active channels automatically

Voice Scrambling (normally between same brand)

Minimum engagement distance
A minimum engagement distance is normally established. Before firing at anyone within 10 feet or 3 meters, the attacking player must first call for surrender and the defending player must answer immediately. He cannot find cover and then answer. If a player fires from within the established distance without calling for surrender, that player is disqualified from the game and the kill does not count. If a player refuses to surrender (not encouraged to) then both players may fire. In most instances, if a player is taken by surprise, he should surrender as an act of good faith.

Sniper rifles have a minimum engagement distance that can go from 14 to 40 meters (46 ft to 131 ft) minimum range, depending of the BB weight/velocity used. This is both for safety (due to upgraded power) as well as to increase realism. Under this range, snipers must use alternate weapons (backups).

Optional Airsoft rules
The following rules are optional ones that you may or may not want to use in your Airsoft games.

Medics:
One player on each team can be designated as a medic and this person has the ability to 'resurrect' players once during a game, allowing them to return to play. When using medics in your Airsoft games it's important to remember to stay lying on the ground where you were 'killed'. The medic has to get to you and touch you in order for you to be 'resurrected'. If you are standing in or on unsafe terrain such as water, mud, broken glass, etc. then you are allowed to lie down near where you were hit so that you don't hurt or endanger yourself.

Multiple lives:
Sometimes it's beneficial to allow players more than 1 life when playing games. This allows a larger variety of scenarios to be played with fewer players present. For instance a few players with 2 lives each could be defending a bunker/structure from 6 or more attackers that have only 1 life each for the game. This allows the defenders to stay in the game longer. When a player that has multiple lives gets hit he calls himself out as normal but instead of just saying 'hit!' he should say 'first hit!'. This lets everyone know that he isn't dead yet. This player now has 30 seconds that he cannot shoot or be shot at. Any shots at this player at this time do not count. The player can use this time to get to better cover but he cannot use it to run towards an attacker and he is only allowed to get behind the nearest cover available to him. This prevents unusual situations from occurring where a player with multiple lives gets hit and during his 30 seconds decides to run directly towards his attackers and to use cover behind them, etc.

Damageable weapons:
Some people prefer to play that if a weapon is struck it cannot be used for the rest of the game. This prevents people from pointing just their weapon around a corner and firing blindly, which can be VERY dangerous to those playing the game. Obviously, if a player that only has a single Airsoft weapon gets his weapon hit then he is considered 'killed' because he has no further use in the game.

Locational damage:
If you are playing with people that you trust (i.e. good friends) then you may want to try this slightly more involved system for damage. Instead of a player being considered 'killed' if he is hit anywhere on the body this optional rule allows players to remain playing in a 'crippled' capacity as long as they aren't hit in a Vital region. Hits to the Head, Neck, Chest, Stomach, or back are considered vital areas and you are 'killed' as normal if you are hit in one of these areas. Hits to the arms or legs force you to not be able to use them until the end of the current game. A second hit to an already damaged arm or leg means you are considered 'killed' as normal. A hit limb CANNOT BE USED FOR ANYTHING AT ALL. This means that if your leg is hit you must hop or crawl, if your arm is hit you aren't allowed to brace yourself on it, open doors with it, hold your gun with it, etc. It must hag limp or be tucked against your body. You can see why this rule can only really be used with friends that you trust because it's very difficult to enforce.

No head hits:
Some groups play that head hits don't count in order to discourage players from shooting at each others faces. This is mostly for safety reasons.

Game Variants
Last man standing (Ultimos homo statans)
All against all in a game often with limited time and area

Terminate (Team mot team)
Two teams that fight against each other until time has run out or one team has been annihilated

Capture the Flag
Two teams play against each other and try to take the other team's flag back to their on base (flag). The flag has to be carried clearly visible. This game can be played in two variants, 'Live Flag' or 'Dead Flag'. In Live Flag the flag is dropped if the Flag carrier is shot, and another player can pick the flag up. In 'Dead Flag' the Flag carrier has to return the Flag to the enemy's base, if the Flag carrier gets eliminated, before the Flag can be taken again.

Two bases one flag
In this game there are two bases, but only one flag and that flag is placed in the middle of the field between the two bases. One team begins in each base. To goal of this game is to take the Flag to the enemies' base. When the flag reaches the enemies base, the enemy loses. If the flag carrier is eliminated anyone can pick up the flag.

Grab the flag
Two teams, or more, that tries to be the first to reach the flag. The team that has the first player to reach the flag, alive, wins. This game should be played in fairly open terrain.

Traitors
Again two teams and this is a version of Capture the Flag. But the judges discreetly choose one player from each team that is given both teams' team-markers. Try to choose a player that hasn't had much luck during the day. Inform the teams that each team has a traitor. The game is played as Capture the Flag, but after the game has lasted for 5 minutes the traitors can change team anytime they chooses. Don't trust your team mates.

Manhunt
A voluntary player is the prey and the rest of the players are the hunters. The prey is given a pistol and some ammo, and the hunters can have whatever they want. The hunters should be between 4-10. The prey wins if he can reach a specific place within the timeframe. The hunter that shoots the prey wins otherwise. The hunters can't shoot each other.

Bounty Hunters
An everyman for himself game, where each player is issued a team-marker. Then the start signal is given all players runs out in the field. When the next signal is given the game starts. When someone is eliminated, the shooter gets the eliminated team marker. The shooter chooses if the eliminated should go to the shooter or if the shooter should collect the team marker himself. Team-forming is not allowed and the formers are disqualified. Game time should be at least one hour and the winner is the player with the most markers.

Wanted, Preferred Dead
A small team, 20% of the players (Prisoners) shall travel thru an area that is guarded by 80% of the players. The prisoners can't have any big weapons or support weapons. The guards can have whatever they choose. Each prisoner that reaches the goal is considered a winner. Time limit is somewhere between 30 minutes to many hours.

Commando Raid
A small group is the commandos. The rest off the players is divided to guard the objectives. The defender goes out to the field and begins to guard the objectives. Each objective should be guarded by the same amount of guards as the commandos are. The commandos are taken to a small zone outside the game area. This is their Insertion and Extraction. Point. When the commandos have finished with the mission, at least 1/3 has to return to this zone or they can't win. Inform the commandos that they have to reach a point in the game area, the 'Drop zone', where they will find information about what target they should attack and find the Flag. When they have taken the Flag from the objective they should leave the 'Flag' at the 'Drop Zone' and then return to the Extraction Point. There should be a time limit. The guards can barricade themselves and send out patrols, but not leave the objectives unprotected.

Paratroopers
Two teams are divided. 1/4 of the players are the Paratroopers and they're blindfolded and taken out to their 'Drop Zone'. At the drop zone they're given a simple map over the area. The other players are split to defend 3 objects in the area. The goal for the paratroopers is to 'take out' an objective by stealing its Flag and return with the Flag to the 'Pickup Zone'. When the judge at the 'Pickup Zone' has the Flag the paratroopers has won. The map should have faults and one of the objectives should be marked at the wrong place, or an extra flag could be marked.

Hostage rescue
Two teams are again divided. One team is divided into 'Hostage' and 'Rescue', while the other team is Guards. The hostage has to be divided to different locations. The rescue team can carry extra weaponry to the hostage. The hostage can attempt to flee but they can then be eliminated (Shot trying to escape). 50% of the Hostage has to be rescued

SWAT terrorist elimination
Classic. A SWAT Team (25% of the players) shall clear an area of terrorists. Buildings are preferred for this variant.

King of the Hill
1/3 of the players barricade themselves on a hill or relatively open area and the rest of the players are the attackers. On the top of the hill is a Flag, and the team that is closest to the flag when the time is out, wins. The hill should offer quite a bit of cover on its slopes.

Zombies
This is another Team vs. Team game, but all the eliminated players go to a third start point. When three eliminated players have reached that point, they form a zombie team and can play again. The new zombie team fights against all other teams, including other zombie teams. The game ends when there is only one player left from anyone of the original teams.

Trenches
A rectangular area about 50x125 m is divided into 10 sectors, 2x5. The two teams should be big, 15-40 players, and they start on the opposite short sides of the field. The team that controls most sectors when the game ends, wins. It takes at least 2 men and no enemies in a sector to control it. The flesh wound rule is used.

CQB (Close Quarter Battle)
Indoor versions of many games. Often played in a big house or in many houses.