We are working on this long awaited mod for Return to Castle Wolfenstein (2001). You'll be able to play the whole campaign + new maps with your friends!
Return to Castle Wolfenstein™ cooperative missions pack - Devil's Manor, Devil's Manor 2 Edge of Darkness, Vendetta, Dark Matter's.
put coop_YoshikPack.pk3 in this place "C:\Users\YourComputerName\Documents\RTCWCoop\coopmain"
To work correctly, you must have a installed cooperative version Project 51