A pioneering team-based tactical shooter that defined the attack-versus-defend multiplayer meta with tight economy management and round-based intensity.
- Developer: Valve (with Minh Le and Jess Cliffe; evolved from Half-Life mod)
- Year/Platforms: 1999 mod; 2000 retail (Windows; later multiple platforms)
- Genre: Tactical FPS
- Core mechanics: Terrorists vs Counter-Terrorists, bomb defusal/hostage rescue, money economy across rounds, recoil/spray control
- Reception: Massive competitive and LAN popularity; foundational to modern esports and FPS design