The Call of Cthulhu intellectual property originates from the 1926 short story “The Call of Cthulhu” by American author H. P. Lovecraft, first published in the pulp magazine Weird Tales in 1928. This story introduced the now-iconic cosmic entity Cthulhu, a vast, ancient being that slumbers beneath the Pacific Ocean in the sunken city of R’lyeh, awaiting the time when it will rise again. Lovecraft’s work blended horror, science fiction, and philosophical pessimism, establishing what became known as the Cthulhu Mythos—a shared fictional universe populated by incomprehensible deities and forbidden knowledge. Over the decades, the Mythos inspired a vast range of derivative works, including literature, films, video games, and the Call of Cthulhu tabletop role-playing game (first published by Chaosium in 1981), which helped transform Lovecraft’s creation into a lasting and globally recognized horror franchise.

A tabletop role-playing game (TRPG) is a form of collaborative, narrative-driven gameplay in which participants assume the roles of fictional characters and collectively create a story within a shared setting. Guided by a game master (GM)—who describes the environment, plays supporting characters, and adjudicates rules—players declare their characters’ actions, which are resolved through a combination of storytelling, rule systems, and often random elements such as dice rolls. Unlike board games or video games, TRPGs emphasize open-ended interaction and player agency, allowing for improvisation, character development, and emergent plotlines. Originating with Dungeons & Dragons in 1974, the TRPG hobby has since expanded into a wide variety of genres, systems, and styles, ranging from high fantasy and science fiction to mystery, horror, and historical simulation.