Baator

The Nine Hells of Baator, sometimes called just the Nine Hells or Baator, are an evil aligned realm in the Astral Sea and the home of the devils and their master, Asmodeus, god of tyranny, domination and sin.

History
Legend says that is was once home to the god known as He Who Was. Asmodeus served him as exarch and archangel, then betrayed him, killing him and erasing his name form history and creation. As a result, Asmodeous and those that followed him were transformed into the devils, with the realm becoming the Nine Hells of Baator, their prison.

Organization
The Nine Hells are organized like a feudal society, each lead by a Duke of Hell, and all ruled by the iron fist of Asmodeus. Each one commands legions of devils, under the command of the pit fiend, the feudal lords and generals of Hell's army. Hell is administered by the Dark Eight, eight pit fiends that serve as administration and leaders of the Blood War against the demons of the Abyss. Each member of the Dark Eight takes the name of his or her predecessor upon ascension, creating the illusion of immortality and continuity, despite the assassinations and overthrow that caused the opening.

Avernus
The first Hell, Avernus, is a wasteland where iron fortresses rise between rivers of magma, under a sunless sky raining embers upon it, and legions of devils serving in the Blood War march. The pit fiend Bel, a military genius, rules this plane. Astral vessels have been known to be pulled into this level of Hell where survivors are slaughtered by devils. The River Styx, a waterway that runs through the planes, and the Nine Hells is one of the only safe routes to take.

Dis
Through a great iron gate in the mountains of Avernus is Dis, the second Hell. Dis is a massive walled city within a vast cavern, sprawling unevenly amid a jagged, mountainous floor. Dispater, famous as the most calculating and cautious archdevil, rules this Hell.

Minauros
Dis gradualy descends into Minauros, the third Hell. A constant oily rain falls from the ceiling on to the black soil of the third Hell, which is filled with mud flats, swamps and mires, some of which are heated by stinking, bubbling mud volcanos. Minauros is ruled by Mammon, a serpentine and supremely boastful archdevil.

Phlegethos
The fourth Hell, Phlegethos, lies far below the third. Dank steps lead to a fiery cavern where lava pours from the ceiling and the air ripples with heat distortion. Fierna rules this Hell alongside her father, Belial, who is the real power behind the throne.

Stygia
As deep as Phlegethos, but miles away, under Dis, is the fifth Hell, Stygia. It is the opposite of Phlegethos, a place of cold and darkness, a vast frozen sea of towering icebergs, where auroras of blue-green frostfire dance above the sea, casting long and dark shadows. The Duke of the Fifth, Levistus, is trapped in an iceberg for some past betrayal against Asmodeus, but was too good at his job to replace. His servants try to free him, but the ice keeps reforming.

Malbolge
Long icey canals lead miles from Stygia to a great cavern, illuminated by thousands of sinister yellow-green lanterns, acting line tiny suns, this is Malbolge, the sixth Hell. Once, it was the garden of the god who ruled before Asmodeus, but now, it is twisted with tall trees with grasping roots and impaled corpses on their limbs, shimmering ponds of poison water and such. The beautiful archdevil, Glasya, daughter of Asmodeus and Princess of Hell, rules Malbolge as Duke of the Sixth.

Maladomini
A tremendous maze of long, winding tunnels filled with crumbling cities, sludge-filled rivers and land stripped of every resource, comprises the seventh Hell, Maladomini. It is an endless maze with passages to nowhere, or to other places in Hell. Black ichor erupts from the ground and swarms of flies attack all who enter. The ruler of this place is a compassionless, sluglike monstrosity known as Baalzebul.

Cania
The eighth Hell, Cania, makes Stygia seem a paradise. It is a vast gulf within the world where mile high glaciers grind across the forbidding frozen landscape so cold that few creatures are able to bear its icy temperatures. Mephistopheles, a wickedly handsome archdevil, rules Cania in a tower of ice, illuminated by hellfire.

Nessus
Down the deepest and darkest rift of Cania lies Nessus, the ninth and deepest Hell. It a vast vertical maze of chasms so deep, it is rooted in the fiery core of Baator itself. Great cities and vast armies lay hidden in the chasm. Nessus is ruled by the tyrant god Asmodeus himself, Duke of the Ninth, King of Hell, father of all devils.