Ravenloft

Ravenloft is a gothic horror campaign setting for the Dungeons & Dragons role-playing game. Originally designed by Tracy & Laura Hickman, it was licensed by Wizards of the Coast to Arthaus, who published a new edition compatible with the d20 3.5 rules along with various supplements. Rights to Ravenloft reverted to Wizards on August 15, 2005, though Arthaus were allowed to continue selling their back stock until June 2006.

Summary
Ravenloft is an alternate time-space existence called a "pocket dimension" with the name "the Demiplane of Dread", which consists of a collection of land pieces called "domains" and the lands are brought together by a mysterious force known only as "The Dark Powers". Each domain is mystically ruled by a being called a "darklord", which is a person or monster who has committed an act or acts of evil so foul as to attract special attention from the Dark Powers. The darklords are imprisoned within the borders of their domains and cannot escape by any means, although most can seal their domain borders with a thought. Within their domains, the darklords are forever tormented by the objects of their desire (often the objects they committed their crimes to achieve), which the Dark Powers dangle before them like the fruits of Tantalus. Each darklord's desires and motivations differ; some desire love, others hunger for glorious victory, or one might envy the defeat and humiliation of their enemies like another rival darklord.