Counter-Strike (commonly abbreviated to CS) is a tactical first-person shooter video game which originated from a Half-Life modification by Minh “Gooseman” Le and Jess “Cliffe” Cliffe, and features real-world weapons. The game has been expanded into a series since its original release, which currently includes Counter-Strike: Condition Zero, Counter-Strike: Source, Counter-Strike: Anthology and Counter-Strike on Xbox.