Airsoft is a team game in which participants eliminate opposing players by tagging them out of play with spherical plastic projectiles shot with mock air weapons called airsoft guns. Although similar to paintball in concept and gameplay, airsoft pellets do not leave visible markings on their target and hits are not always apparent. Though the pellets may leave small bruises or welts on exposed skin (protective gear recommended), the game relies heavily on an honor system in which players who have been hit are expected to call themselves out by shouting "HIT".
The airsoft guns used are mostly magazine-fed, with some having manual/battery-powered spring-piston pump power plants similar to Nerf Blasters, or pneumatically powered by compressed green gas or CO2 canisters. Many airsoft guns also have mounting platforms compatible with genuine firearm accessories, and cosmetically more resembling real firearms. This makes them popular for military simulation and historical reenactments. There are also professional gun safety and weapon manipulation training conducted with airsoft in some fields, such as law enforcement training, due to better safety and lower cost.
Airsoft gameplay varies in style and composition, but often ranges from action shooting to short organized live action role-playing (LARP) scenarios, close quarters battle skirmishes (what you'll experience at Advanced Action Sports), military simulations (MilSim) or historical reenactments. It is played in indoor courses or outdoor fields. Combat situations on the field may involve the use of genuine military tactics to achieve objectives set in each game. Participants may attempt to emulate the tactical equipment and accessories used by modern military and police organizations. Games are kept safe by trained professionals acting as supervisors and referees. Before gameplay, an airsoft gun's muzzle velocity is checked through a chronograph and measured in feet per second (FPS) and Joules, a measurement of kinetic energy.