In the Dungeons & Dragons fantasy role-playing game, Carceri (more fully, the Tarterian Depths of Carceri; also, Tarterus or The Red Prison) is a neutral (chaotic) evil-aligned plane of existence. It is one of a number of alignment-based Outer Planes that form part of the standard Dungeons & Dragons (D&D) cosmology, used in the Planescape, Greyhawk and some editions of the Forgotten Realms campaign settings.
The plane known as Tarterus was mentioned for the first time by name in the article "Planes: The Concepts of Spatial, Temporal and Physical Relationships in D&D", in The Dragon #8, released July 1977. The plane was mentioned again in an appendix of the known planes of existence in the original (1st edition) AD&D Players Handbook, published in June 1978, where it was described as "The planes of Tarterus of evil chaotic neutrals".
Carceri has six layers, contained inside each other not unlike the shells of a matryoshka doll. Each layer consists of a series of orbs floating in an infinite black void. Light is provided by the orbs only; as one progresses through the layer, the light diminishes, and the orbs are separated by larger and larger distances.
Skullrot, an asylum run on behalf of the Demon Lord Graz'zt by his lich-fiend lieutenant, Dark Myrakul, may also be found on Carceri. The fallen Celestial Adimarchus is currently imprisoned here, exiled from his role as Demon Lord of the 507th Layer of the Abyss, Occipitus.
The first layer, Othrys, consists of a war-ravaged landscape of swamps and stagnant rivers crossed only by spotted ranges of mountains. Several Greek Titans live on Othrys in the realm of Mount Othrys. Furthermore, Raiden maintains his Palace of Thunder on Othrys.
The second layer, Cathrys (also called The Crimson Jungle), is a layer of thick jungles and open plains of razored grass. Talona's realm, the Palace of Poison Tears, can be found on Cathrys, as can The Steading, the realm of hill giant deity Grolantor.
The third layer, Minethys, is a parched layer of crimson glowing sand and biting, desiccating sandstorms. Notable locations on Minethys include Coeus' Temple, dedicated to the Titan of the same name; The Mausoleum of Pain of the dragon god Faluzure; Karontor's Rack of Injustice; and Trickster's Delight, the realm of the naga deity Parrafaire.
The fourth layer, Colothys, consists of jagged, unforgiving mountains and sudden chasms with little flat ground to find refuge. Crius' Temple, dedicated to the Titan of the same name, can be found here. Ellaniath, the realm of the drow deity Vhaeraun, and The Land of the Hunt, realm of the god Malar, are located on Colothys.
The fifth layer, Porphatys, is a cold layer dominated by a shallow, acidic ocean, cut only by sand bars and drifts of semi-solid acid snow. Oceanus' Temple, dedicated to the Titan of the same name, is located on Porphatys.
The last layer, Agathys, consists of a single orb of black ice alone in the void, almost completely devoid of light and sound, with only the shifting and breaking of ice and the slow, crushing agony of petitioners frozen in it being heard. Apomps' Three-Sided Palace, realm of the demodand (gehreleth) lord Apomps, can be found on Agathys. The god Nerull from the World of Greyhawk setting also makes his home on Agathys.
- Carceri is based on Tartarus in Greek mythology. Its name is the Italian word for prison.
- Othrys is named after Mount Othrys in Greece, which according to legend was a base for the Titans.
- Cook, Monte: The Planewalker's Handbook, p. 20, TSR 2620
- Gygax, Gary (July 1977). "Planes: The Concepts of Spatial, Temporal and Physical Relationships in D&D". The Dragon #8 (TSR) I (8): 4.
- Gygax, Gary (1978). Players Handbook. TSR. ISBN 0-935696-01-6.
- Decker, Jesse, et al.: Shackled City Wizards of the Coast ©2007
- Zero Pseudonym. "The Shackled City | Obsidian Portal" obsidianportal.com. AisleTen, LLC., n.d. Web. 22 Aug. 2012.