Counter-Strike is a team-based multiplayer tactical first-person shooter in which players join either the Terrorist or Counter-Terrorist side and compete in objective-based rounds. The primary game modes involve bomb defusal and hostage rescue, played across designated maps. Players purchase weapons and equipment between rounds using money earned from eliminations and completed objectives, and eliminated players must wait until the next round to respawn. Originally a fan-made modification for Half-Life created by Minh Le and Jess Cliffe in 1999, it was acquired by Valve and released as a standalone retail product in 2000, becoming one of the most influential first-person shooters and spawning multiple sequels including Counter-Strike: Source, Global Offensive, and Counter-Strike 2.