Call of Cthulhu is a roleplaying game of secrets, mysteries, and horror based upon the worlds of H. P. Lovecraft. Playing the role of steadfast investigators, you travel to strange and dangerous places, uncover foul plots, and stand against the terrors of the Cthulhu Mythos. This 7th Edition of the Keeper's Rulebook contains the core rules, background, guidance, spells, and monsters of Call of Cthulhu, and is backwards-compatible with all other available Call of Cthulhu titles.