Call of the Cthulhu: Guardian Rulebook The calling of Cthulhu is H.P. It is a table-role-playing game that covers the world of Lovecraft. The call of Cthulhu is full of secrets, riddles, and horror. Be a courageous explorer, go to strange and dangerous places, uncover the evil plot, and face the horrors of Cthulhu myth. It also meets with beings, monsters, and mad scholars who disrupt the ideals. In the strange books that contain forgotten knowledge, they acquire knowledge that humans should not be aware of. Your actions may determine the fate of the world. This book is a guidebook of the key rules, background information, instructions, spells, and monsters. Can be used by defenders of confidential knowledge to present adventures to other players. You must have at least one book to play the call of Cthulhu. Other players, explorers, recommend that you have at least one explorer handbook. The explorer handbook contains additional resources on character making, functions, jobs, equipment, and so on.