Counter-Strike: Condition Zero is a multiplayer video game and the follow-up to Counter-Strike. The game was released in 2004 using the GoldSrc engine. Condition Zero features a multiplayer mode, which features updated character models, textures, maps and other graphical tweaks. It also includes two single-player campaigns, including Condition Zero: Deleted Scenes. Alongside various other Valve titles, the game received versions for OS X and Linux in 2013.