Cthulhu-Rollenspiel

Cthulhu-Rollenspiel is a 5-book series with 5 released primary works first released in 1981 with contributions by Sandy Petersen, Lynn Willis, Kevin Ross, Mike Mason, Yurek Chodak, Tadashi Ehara, Harry Henderson, Charlie Krank, Steve Perrin, Greg Stafford, Anders Swenson, and Inc Staff Chaosium.