Airsoft?

Here is the extensive wiki on airsoft.

Airsoft is a term for a sport, as well as for a type of air gun. It can be similar to paintball, but is much more realistic. Airsoft can be a sport, and a game, but it can also be a tactical simulation for training purposes.

Airsoft is as safe as paintball. The majority of the injuries are more often in relation to intense physical activity than they are the projectile being the cause of injury. Some official fields require full masks, but most players just use face sealing goggles that are ballistically rated. As of yet, the only known fatality related to airsoft is of an elderly lady in Japan.

The replica weapons fire a plastic BB. They can be powered by springs, electric motors, or gas.

While generally viewed as somewhere between toy and air gun (in the classic BB’s and pellets style), some regions have specific laws concerning them. Some cities in New Jersey have banned them. Check your local laws.

If you are new to airsoft, this is not the place for you. I recommend reading the wiki if you want to know how to get started.