Return to Castle Wolfenstein is a first person shooter game made by Gray Matter Studios and id Software and published by Activision in 2001. The multi-player part was developed by Nerve Software.
It is powered by a heavily-modified version of the Quake III Arena engine.
Return to Castle Wolfenstein is remake of sorts of the early, seminal first-person shooter, Wolfenstein 3D. However, with the advances in graphics technology and gameplay design since the original, without the name and the occasional in-game references it would be unrecognisable as a remake.
It features a story-based single-player campaign (taking up many of the themes, such as they were, in the original game), as well as a team-based networked multiplayer version which features different character classes which must work together to win.
A multiplayer spinoff of the series, Enemy Territory, was originally planned as a full-fledged expansion covering both the SP and MP bases, however, iD Software decided to abandon the SP portion due to a supposed lack of interest.