Half-Life: Opposing Force is the official game expansion for Half-Life, the thrilling PC CD-ROM named "Game of the Year" by over 50 publications. In Opposing Force (a.k.a. "Op For"), players return to the Black Mesa Research Facility to experience an entirely new episode of single player action. In addition, Op For also contains a massive collection of new multiplayer content.

Minimum Specifications: Pentium 233 32 MB RAM SVGA Voodoo

Recommended Specifications: Pentium II 266 32 MB RAM SVGA 4MB OpenGL