Ravenstone Sanitarium, written by John Gary Pettit, is an adventure module for the Call of Cthulhu role-playing game by Chaosium. It was released in 2008.
It provides game mechanics for dissociative identity disorder (multiple personality disorder) characters, and allows a player to create and play characters which are fragments of a mentally ill person's mind. It also adds a new rule and game mechanic, the Personality Check, modifying the standard and ubiquitous Sanity Check.
Synopsis[]
There are two adventures provided.
In the first, the player is playing a character who has already failed one too many Sanity checks and is in an asylum for the insane. The player generates characters that are fragments of their own mind.
In the second, set ten years later than the first sequence, the player characters are investigating the same asylum to find out what nightmarish secret it has hidden all along.
The adventure features the first appearance of the Great Old One Xchthol.
Behind the Mythos[]
This adventure module, containing two adventures, was part of the Miskatonic University Library Association monograph series. These works featured rules, situations or other content that was either not standard to the published Call of Cthulhu RPG rules, much more adult in content, or both. Ravenstone Sanitarium was Monograph #0350. To quote Chaosium:
"MISKATONIC UNIVERSITY LIBRARY ASSOCIATION monographs are longer works by one or more authors on a subject of import to Call of Cthulhu roleplayers. On these products the author has also fulfilled the functions of editor and layout artist; we at Chaosium have done little in the way of editorial. We found these works compelling and thought that you would enjoy them. Through the publication of monographs we can offer our most loyal fans more information more easily, and evaluate the potential of these works for eventual release to the wholesale market."