Masque of the Red Death

Masque of the Red Death was originally (in RPG terms) a campaign setting by TSR and Wizards of the Coast for the Dungeons and Dragons system. Named after Edgar Allan Poe's story of the same name, it was an add-on to the Ravenloft campaign setting. Masque of the Red Death had several facets in common with Ravenloft—it was a gothic horror setting, with mysterious powers, and it had restrictions on magic and planar travel similar to Ravenloft's. On the other hand, it was set in a more modern era, an 1890s version of Earth called Gothic Earth.

In this setting, character classes were re-tooled to more modern ones like "Athlete", "Criminal", and "Cowboy", and characters received salaries depending on their career. There were magic-using classes (the Adept) and priest-like ones (the Dilettante), along with some others that were rough parallels of the traditional D&D classes.

The Red Death in this setting was, as were the mists in Ravenloft, a mysterious force that was not strictly defined in the campaign materials. Several theories were floated in the materials to give DMs something to play with. The Red Death was known to raise undead, make people insane or change them into monsters, and move locations around. The Red Death is the source of all magic in the realm.

In 2004, White Wolf published a sourcebook for Masque of the Red Death, using the D20 System, under the Swords and Sorcery imprint. In addition, some of the qabals, and even the Red Death itself, got Cameo mentions in D20 Modern's Urban Fantasy settings.