Mansions of Madness: Vol. 1 – Behind Closed Doors is a collection of five scenarios for the tabletop RPG Call of Cthulhu, published by Chaosium. The book is designed for use with the Call of Cthulhu 7th Edition rules or the Starter Set and includes two updated classic adventures alongside three completely new stories. All of the scenarios can be played as standalone adventures, used as side quests in an ongoing campaign, or linked together into a mini-campaign set during the 1920s.
The supplement focuses on one of the most beloved themes in the world of Call of Cthulhu: the secrets hidden behind the doors of seemingly ordinary houses, mansions, and estates. Investigators encounter strange events, disappearances, curses, and terrifying mysteries that gradually reveal connections to the Cthulhu Mythos.
The book contains five scenarios:
- Mister Corbitt challenges investigators to determine whether a friendly and reserved businessman is hiding a dark secret.
- The Crack'd and Crook'd Manse takes place in the infamous Fitzgerald Manse, which locals have long believed to be cursed.
- The Code brings investigators to Wellington Manor after receiving a mysterious telegram, where a series of bizarre events awaits them.
- The House of Memphis revolves around the disappearance of the famous magician Memphis the Great and the secrets hidden within his residence.
- The Nineteenth Hole explores strange occurrences at a golf course in Scotland, where illnesses, apparitions, and disappearances have begun to plague the area.
The scenarios are designed for up to six players and a Keeper, with each adventure typically taking between one and three game sessions to complete.
Horror fans will enjoy the tense exploration of old houses, forgotten secrets, and peculiar residents. The supplement delivers a strong sense of mystery and suspense, allowing players to gradually uncover the hidden truths lurking behind closed doors.
