Call of Cthulhu (role-playing game)
Call of Cthulhu is a horror fiction role-playing game based on H. P. Lovecraft's story of the same name and the associated Cthulhu Mythos. The game, often abbreviated as CoC, is published by Chaosium; it was first released in 1981 and is in its seventh edition, with licensed foreign language editions available as well. Its game system is based on Chaosium's Basic Role-Playing (BRP) with additions for the horror genre. These include special rules for sanity and luck.
1st edition box cover by Gene Day, 1981.
7th edition cover by Sam Lamont, 2014
"The King in Yellow", illustration by Earl Geier for the Fatal Experiments adventure book. The Yellow Sign adorning the back of the throne was designed by Kevin A. Ross for the Call of Cthulhu scenario Tell Me, Have You Seen the Yellow Sign?
A gamemaster is a person who acts as an organizer, officiant for regarding rules, arbitrator, and moderator for a multiplayer role-playing game. They are more common in co-operative games in which players work together than in competitive games in which players oppose each other. The act performed by a gamemaster is sometimes referred to as "Gamemastering" or simply "GM-ing".
A gamemaster (center) and players in a tabletop role-playing game