Arkham Horror is a cooperative adventure board game designed by Richard Launius, originally published in 1987 by Chaosium. The game is based on Chaosium's roleplaying game Call of Cthulhu, which is set in the Cthulhu mythos of H.P. Lovecraft and other horror writers. The game's second edition was released by Fantasy Flight Games in 2005, with a third edition in 2018.

Cooperative board games are board games in which players work together to achieve a common goal rather than competing against each other. Either the players win the game by reaching a pre-determined objective, or all players lose the game, often by not reaching the objective before a certain event ends the game.