Abyss

The Infinite Layers of the Abyss

The Infinite Layers of the Abyss (pronounced: /ɑːˈbɪs/ a-BIS) is the birth place of the demons, a chaotic evil universe unto itself with uncountable layers of infinite variety connected haphazardly. The Abyss's place in the cosmology of the Forgotten Realms has shifted over time, but the nature of the plane remains fairly constant: a violent, malevolent place where the strong survive on the backs of the weak, the weak conspire to overthrow the strong, alliances last only while convenient, and the landscape itself tortures the mind and body of all who dare to pass.

Cosmology

In the Great Wheel cosmology model, the Abyss was an Outer plane on the Great Wheel connected to the Astral plane, Pandemonium, Carceri, and the Outlands. Some estimated that the Abyss had 666 layers, while the Fraternity of Order claimed to have catalogued 679 layers. It was possible that the number of layers was infinite, but no one could be certain. The first layer, named Pazunia after the demon lord Pazuzu, was described as a barren, dusty place baking under a red sun, broken only by great iron fortresses, huge holes in the ground, and the river Styx. Some branches of the Styx flowed down the holes (which were conduits to the various layers) and some of these holes supplied water to the Styx in reverse waterfalls.
When the Great Wheel model was replaced by the World Tree cosmology model, the river Styx was renamed the River of Blood and it flowed through all the fiendish planes (except for the Supreme Throne and the Demonweb Pits) originating in the Abyss, passing through the Blood Rift—an unusual plane that connected the Abyss with the Nine Hells - bringing the demons even closer to their arch-enemies the devils, resulting in the Blood War. Cosmologists have found evidence of portals between the Abyss and the Barrens of Doom and Despair, Clangor, the Demonweb Pits, and Hammergrim, with intermittent portals to Deep Caverns and Fated Depths. The Astral Plane connects all of the fiendish planes to the Prime Material Plane, but not directly to each other.
After the Spellplague, Asmodeus consumed the essence of the fallen Azuth and ended the Blood War by casting the Abyss to the furthest depths of the Elemental Chaos. The World Axis cosmology described the ruined Abyss as a domain with ever-changing features and realms, where the demons waged futile wars over meaningless empires. Once again the river Styx flowed through the Nine Hells and the Abyss, but then emptied its pollution into the Astral Sea. Other than the Styx or braving the Elemental Chaos, the only known passages to the Abyss are found in the Demonweb Pits, the Dismal Caverns, and Nishrek.

Layers

The number of layers in the Abyss is unknown and perhaps unknowable, but this article attempts to list them regardless of which cosmology model was in favor at the time of discovery. Each layer has its own characteristics, which are as varied as the demons themselves. All types of terrain, atmosphere, weather, gravity, and material composition are represented in the myriad layers. Some examples are:

• Air-dominant - Zero gravity, no matter except air
• Ash - Blowing dunes of ashes
• Battleground - Blood War or other
• City - Warrens and slums to citadels and palaces, teeming with demons
• Earth-dominant - Solid rock tunneled by the inhabitants
• Fire-dominant - Everburning flames with salamanders, etc.
• Delusion - Appears to be Normal but the flowers are poisonous or the trees attack
• Desert - Endless tracts of black, white, or red sand with no water
• Glacier - Infinite black, white, or orange ice with few rocky peaks breaking the surface
• Hellscape - A burning mix of magma, rock, and belching brimstone
• Maelstrom - Swirling, bubbling chaos like Limbo
• Mountainous - Rocky crags, precipitous cliffs, soaring peaks
• Negative-dominant - Major or minor
• Normal - Similar to a Prime plane with various flora and fauna
• Ocean - A trackless ocean, with a surface
• Salt - Crystalline badlands or desert
• Sea - Of acid, blood, garbage, insects, oil, worms, etc.
• Swamp - Noisome bog inhabited by predators
• Undead - Specters, spooks, and ghosts
• Volcanic - Lava flows, earthquakes, volcanoes, and smoke
• Water-dominant - Nightmarish creatures in the murk

Inhabitants

There are myriad types of demons, too numerous to catalog here. Non-demonic life can be found in the Abyss, but is most likely imported from other planes.

Afterlife

Beliefs about the journey of souls to the afterlife changes with the shifting cosmologies and the crystal sphere in which one resided. In some worlds, chaotic evil souls travel directly to the Abyss and become manes, the lowest form of sub-demon. Manes are treated as slaves, cannon fodder, and food by the demon lords. For mortals of Realmspace, however, all souls will first go to the Fugue Plane and await transport to their final resting place. Greedy demon lords can open a portal to the Fugue Plane and conduct raids to steal souls and bring them back to the Abyss to become manes. After the Spellplague, Shar reshaped the Plane of Shadow and folded in what death energy did not get absorbed into the Elemental Chaos and created the Shadowfell. Since then, souls on their way to the afterlife start their journey in the Shadowfell. Most make it to the Fugue Plane to await judgment, but a few remain behind or are lost.

Realms

Relatively few greater powers carve out a realm in the Abyss because dealing with the ubiquitous hordes of demons and ambitious demon lords requires too much of their attention. Those deities for whom the chaotic evil nature of the Abyss is attractive, along with the demon "royalty" whose names are not spoken openly in civil society, are:

• Ahazu the Seizer
• Baphomet - Created an Endless Maze that changes form as it passes between layers. It is populated by a variety of minotaurs said to have breath weapons or magical abilities
• Beshaba - the Goddess of Mischief and Maid of Misfortune once made her home in the Abyss
• Dagon - Controls a watery layer filled with hezrou and aquatic dretch
• Demogorgon - Controls several layers, each filled with dinosaurs, wild apes, and flying monsters as well as the usual demonkind
• Diinkarazan - Crazed twin brother of derro deity Diirinka, was held by a curse in the Prison of the Mad God, the 586th layer
• Eltab - Lurked on this plane in the "Hidden Layer"
• Fraz-Urb'luu - Has a realm that reportedly rivals the beauty of the Twin Paradises or Arvandor, but it is actually an illusion covering decay and rotting flesh
• Garyx the All-Destroyer - Dragon god of fire who makes his lair somewhere in the Abyss
• Gorellik - The abandoned god of the gnolls, spends much of his time wandering the Abyss
• Grankhul - The hunter god of the bugbears, has the 241st layer, Palpitatia, as his divine realm
• Graz'zt - Has a great palace that covers an entire layer where he marshals his armies to fight Orcus and Demogorgon
• The Great Mother - Tyrannical chief deity of the beholders, holds her Realm of a Million Eyes on the 6th Layer
• Grolantor - God of the hill giants, stays in the Abyss when not in his realm in Tarterus
• Juiblex - Lives in a layer full of fungus and rot, where slimes and molds feed off the decaying matter of the plane, and each other
• Kali - The feared Black Earth Mother of the Vedic pantheon, holds sway over both the 500th layer, and the Caverns of the Skull, the 663rd layer
• Kostchtchie - Controls only part of a layer, but his ice palace is filled with creatures of cold
• Laogzed - God of troglodytes, has a realm called the Rotting Plain here
• Lolth- Spun her webs on the 65th layer in the midst of a maelstrom that was the portal to her abode on the 66th layer before she became a greater god and removed her Demonweb Pits from the Abyss to join the fiendish planes. After the Spellplague, her realm survived to float in the Astral Sea
• Merrshaulk - The ancient yuan-ti deity, resides on the 74th layer called Smaragd
• Moander - The Rotting God, has a realm called Offalmound on the 223rd layer, also known as Rarandreth, before his demise
• Obox-ob - Once had a realm here
• Orcus - Has an enormous palace made of bones, rising out of a field of bone dust. He employs many undead as his guards and servants
• The Pack - A group of powerful entities worshiped by the leucrotta, they roam the Abyss in search of prey (usually tanar'ri)
• Pale Night - The Mother of Demons, lives in a bone castle in the maze of Baphomet and controls her own layer called Androlynne
• Pazuzu - Has no real home but controls the skies above every layer of the Abyss. He, like Charon on the Styx, controls a primary mode of travel in the Abyss and is respected if not feared
• The Queen of Chaos  - Rules the fourteenth layer called the Steaming Fen
• Ramenos - The deity of the bullywugs, slumbers on the 74th layer most of the time, sharing Merrshaulk's realm of Smaragd
• Skiggaret - The bugbear god of fear, shared the realm of Palpitatia with his fellow power Grankhul
• Sseth - The god of the yuan-ti, calls his realm on the 74th layer the Viper Pit 
• Tharizdun - The god of destruction who created the Abyss, he was imprisoned in a remote layer of the Abyss during the Dawn War
• Umberlee - The Bitch Queen once hailed from the Abyss 
• Urdlen - The evil gnome deity carved his realm out of a layer of solid rock, crisscrossing it with tunnels filled with hate for beautiful things 
• Vaprak - Deity of trolls and father of ogres, has a realm here on a layer called Shatterstone 
• Yeenoghu - Has a mansion the size of a city that rolls across barren salt flats, pulled by slaves driven by gnolls 
• Zuggtmoy - Has several realms scattered throughout the layers, all echos of normal environments, but bathed in a purplish light and overtaken by fungus and fungoid creatures

Type

Dimensional plane