Call of Cthulhu: Keeper Rulebook

Call of Cthulhu is a tabletop role-playing game in the style of Dungeons & Dragons. The game is, as the name suggests, based on the universe H.P. Lovecraft created back in the 1920s. Players typically start by investigating mysteries and end up meeting several of the infamous creatures from Lovecraft's bizarre mind - Cthulhu, Yog-Sothoth, and Nyarlatothep, for example. This book is designed for the game's Keeper - what corresponds to the Dungeon Master in this system. All core rules, magical powers, monsters, etc. are in the book, and with a single Investigator Handbook for the players, you’re really ready to experience the Cthulhu universe. Call of Cthulhu, 7th edition, is backwards-compatible with all other available Chaosium titles and includes a guide for any conversion needed.