Needed for a lot of Garry's Mod addons.

Insane FPS Co-op

4 Player FPS Co-op

Asymmetric Competitive FPS. Use of a re-balancing mod highly recommended.

Needed for The Specialists 2.1 (Competitive FPS) and Zombie Panic! (Competitive Survival FPS)

Co-op Semi-RPG Platformer

4 Player FPS Co-op

Competitive FPS

FPS Building and Gamemode Sandbox