Call of Cthulhu 7th Edition: Keeper Rulebook

The Keeper Rulebook, contains the core rules, background, guidance, spells, and monsters of the game. It is everything you need for Call of Cthulhu at your fingertips, and will enhance all of your games. The Keeper Rulebook is intended for use by the Keeper of Arcane Lore—the Game Master who will present the scenario to the other players.