Mansions of Madness Vol. 1 contains five scenarios for use with the Call of Cthulhu Starter Set or the 7th Edition Call of Cthulhu: Keeper Rulebook.

It includes two fully updated and revised classics, along with three brand new adventures, and all can be played as standalone adventures, used as sidetracks for ongoing campaigns, or strung together to form a mini-campaign spanning the 1920s. Suitable for up to six players and their Keeper, each scenario should take between one and three sessions to play through, and are an ideal next step for those who have already experienced the horrors contained within the scenario collections Doors to Darkness and Gateways to Terror.