Free video and computer games where the player controls a single character, usually a person, exploring an environment, usually three dimensional, and shooting enemies as they appear. The enemies may shoot back or simply rush to close and destroy the character in melee. Often different weapons can be found or earned. Often it takes several hits to destroy a character or the more powerful enemies.
"First person shooter" games, started by Castle Wolfenstein 3D, simulate the player seeing through the character's eyes. "Third person shooter" games present a side or top view of the character and environment.