Counter-Strike: Condition Zero (CS:CZ or CZ) is a multiplayer first-person-shooter and the follow-up to the original Counter-Strike. The game was released in 2004 using the GoldSrc Half-Life engine.

CS:CZ features updated character models, textures, maps and other small graphical tweaks. As well as a multiplayer component, Condition Zero also introduces a short single-player mission pack against computer controlled player 'bots'. You play the game from the perspective of a Counter-Terrorist agent, and to complete each map you must pass certain requirements, including targets such as "kill 3 enemies with a glock" or "kill all enemies in 45 seconds".