INFINITE LAYERS
OF THE ABYSS

It is an infinity of clutching horror.

It is home to demons.
It is where morality crumbles and ethics perish.
The Abyss is all that is ugly, all that is evil, and all that is chaotic reflected
in infinite variety through layers beyond count. Its virtually endless layers
spiral downward into ever more atrocious forms. Conventional wisdom places the
number of layers of the Abyss at 666, though there may be far more. The whole
point of the Abyss, after all, is that it’s far more terrible than conventional
wisdom could ever encompass.
Each layer of the Abyss has its own unique, horrific environment. No theme unifies
the multifarious layers other than their harsh, inhospitable nature. Lakes of
caustic acid, clouds of noxious fumes, caverns of razorsharp spikes, and landscapes
of magma are all possibilities. So are less immediately
deadly terrains such as parched salt deserts, subtly poisonous winds, and plains
of biting insects. The Abyss is home to demons, creatures devoted to death and
destruction. A demon in the Abyss looks upon visitors as food or a source of
amusement. Some see powerful visitors as potential recruits (willing or not)
in the never-ending war that pits demons against devils: the Blood War.
Demon lords and deities inhabit the Abyss, including Demogorgon, Graz’zt, Pazuzu,
Blibdoolpoolp (deity of kuotoa), Diirinka (deity of the derro), the Great Mother
(deity of beholders), Gruumsh (deity of orcs), Hruggek (deity of bugbears), and many
others, including the well-known deity Lolth (draw deity and queen of the demonweb
pits).
Other demon princes include Yeenoghu, Alzrius, Baphomet, Eldanoth, Fraz Urblu,
Juiblex, Kostchtchie, Lissa’aera, Lupercio, Lynkhab, Pale Night, Verin, and
Vucarik.

As noted before, the Abyss has layers beyond count, though the top layer is
well-known: the Plain of Infinite Portals.

ABYSSAL TRAITS

The Abyss has the following traits.

* Normal Gravity: The top layer of the Abyss, the Plain of Infinite Portals,
and many other layers have the normal gravity trait, but other layers of the
Abyss can contain wildly different gravity traits that run the gamut of possibilities.
* Normal Time: Time flows at the same rate in the Abyss as on the Material Plane.
However, rumors persist of a layer where time flows backward with regard to
aging. The reverse flow is erratic, however, and a visitor could be reverse-aged
to childhood or out of existence altogether.
* Infinite Size: The Abyss goes on forever in the form of an infinite number
of layers, although its well-known realms are bounded.
* Divinely Morphic: Entities at least as powerful as lesser deities can alter
the Abyss. Less powerful creatures find the Abyss indistinguishable from a normal
Material Plane (alterable morphic trait) in that the plane can be changed by
spells and physical effort.
* Mixed Elemental and Energy Traits: This trait varies widely from layer to
layer. In the Abyss as a whole, no one element or energy constantly dominates,
though certain layers have a dominant element or energy, or a mixture of two
or more.
* Mildly Chaos-Aligned and Mildly Evil-Aligned: Lawful characters in the Abyss
suffer a –2 penalty on all Charisma-based checks, and good characters suffer
the same penalty. Lawful good characters suffer a –4 penalty on all Charisma-based
checks.
* Normal Magic.

ABYSSAL LINKS

The two most well-known access points to the Abyss are a gate
in the Outlands from the town of Plague-Mort, and the River Styx. Both of these
links provide access to the top layer of the Abyss, the plain of Infinite Portals.

ABYSSAL INHABITANTS

Called Demonholme by some, the Abyss harbors demons and is likely
their ultimate source. Demons rule most known layers of the Abyss. Other evil
creatures reside among the layers as well, including bebiliths, bodaks, retrievers,
undead of every sort, renegade devils, twisted mortals, and worse. A class of demons called tanar’ri are the unchallenged masters
of the Abyss, although the nigh-infinite variety of the plane means some areas
exist beyond their reach.

Abyssal Petitioners

Those souls from the Material Plane that are not simply absorbed
into the structure of the Abyss become petitioners called manes. Manes have
pale white skin, cruel claws, sharp teeth, sparse hair, and white eyes. Often,
maggots visibly squirm through a mane’s bloated flesh. Manes that survive many
years are sometimes “promoted” to lesser demon types, though they retain no
memory of their former lives. Manes have the following special petitioner qualities:
Additional Immunities: Electricity, poison.
Resistances: Fire 20, acid 20.
Other Special Qualities: Acidic vapor, no planar commitment.
Acidic Vapor (Su): When a mane is slain, it discorporates into a cloud of noxious
vapor. Anyone within 10 feet of a slain mane who fails a Reflex save (DC 20)
takes 1d6 points of acid damage.
No Planar Commitment (Ex): Unlike most other petitioners, manes can leave the
plane they call home.

MOVEMENT AND COMBAT

In general, the Abyss functions like the Material plane with
regard to movement and combat. On layers where the environment is radically
strange, different rules apply. Individual layers of the Abyss could have the
firedominant trait, for example, or have subjective directional gravity. Unless
stated otherwise, those traits function the same in the Abyss as they do everywhere
else.

THE SHIPS OF CHAOS

Demons sometimes move from plane to plane in entropic vessels
formed of powdered bones, crushed spirits, and petitioners. Meant for use against
devils in the Blood War, these ships of chaos have wild powers specifically
designed to counter the effects of law. The tanar’ri have commissioned only
a very few ships of chaos, but the few demon-crewed ships that do sail the planes
are a terror to behold. For brave or foolhardy travelers, the tanar’ri sell
passage on a ship of chaos, if the price is right.

FEATURES
OF THE ABYSS

The Abyss has more layers than anyone knows, mortal or deity.
A few of the most well known are described below. Vision in the Abyss is normal
except on layers where environmental conditions inhibit it. Unless noted otherwise,
hellish suns, phantom glows, or similarly unpleasant radiances illuminate all
layers of the Abyss. Unless a particular layer somehow inhibits sound, hearing
is also normal in the Abyss.

Plain of Infinite Portals

This is the topmost of the uncountable Abyssal layers. It is
a barren, dusty place without life or greenery, baking beneath a hell-red sun.
The dusty plains are broken by three features: huge pits in the earth, great
iron strongholds, and the River Styx. The pits of this first layer are portals
to deeper layers. Dropping down a given pit soon deposits the traveler into
the associated layer, though jumping into random pits that lead to unknown planes
of the Abyss is insanely dangerous. Most of the pits are two-way portals, but
some are only one-way, leaving travelers stranded on the new layer.

RANDOM ABYSSAL LAYERS

What if your characters wind up being sent to the Abyss as a
result of an adventure gone wrong? Or what if they flee powerful demons on the
Plain of Infinite Portals by jumping down the nearest pit? Use the following table to randomly determine the general terrain
type of an unknown layer. If desired, roll twice (or more) and combine the results.
d% Type of Layer
01–05 Air-dominant
06–10 Blood War battleground (demons against devils)
11–15 Burning hellscape
16–20 Demonic city

21–25 Desert of sand, ice, salt, or ash
26–30 Earth-dominant
31–35 Fire-dominant
36–40 Grass plain (filled with predators)
41–45 Mixed elemental-dominant (as Limbo)
46–50 Mountainous

51–55 Negative-dominant (minor or major)
56–60 Normal (as the Material Plane)
61–65 Ocean of water
66–70 Realm of powerful Abyssal entity
71–75 Sea of acid
76–80 Sea of insects

81–85 Sea of magma
86–90 Subterranean
91–95 Undead realm
96–100 Water-dominant

Iron strongholds here most often house powerful demons and their
court. Such fortresses often serve as a rallying point for demonic armies on
their way to join the endless Blood War. Some of that war’s greatest battles
take plane in this layer, deeper layers, and nearby Outer Planes. The River
Styx flows a winding course on this layer. Some channels pour into the pits,
while other pits well up with foul water, serving as tributaries of the mighty
river. A character entering a new, unknown layer of the Abyss via a pit (or
another method) can wind up in almost any sort of terrain. Develop this layer
of the Abyss yourself, or use the Random Abyssal Layers sidebar to provide guidance.
Broken Reach: Red Shroud, a succubus sorcerer,
rules the town of Broken Reach, which serves as a gathering point for Blood
War mercenaries, a way spot for travelers insane enough to explore the Abyss,
and a place for trade. The town is a set of crumbling towers surrounded by outworks
of trenches, walls, and spiky barricades. Several important precincts are underground.
The portal to Plague-Mort, a town in the Outlands, is beneath the main hall,
for example. The food stores, the arsenal, the interrogation halls, and the
crypts are likewise underground, connected by narrow tunnels. Rooms for visiting
mercenaries and merchants are above ground, off the main towered hall. The inhabitants
are a mix of petitioner slaves, demons of all types, and mercenaries from the
Material Plane and beyond.

Ferrug: An abandoned iron stronghold is situated
near the Lakes of Molten Iron, a series of natural whitehot crucibles filled
with molten iron. Ferrug’s former demonic lord was slain as she lay senseless
while astrally traveling to the Material Plane to corrupt mortal hearts. Since
then, Ferrug has hosted countless armies of demons interested in gathering workable
iron to build other iron strongholds. Because the demons highly value iron,
devil strike forces often attack the Lakes of Molten Iron, so Ferrug currently
serves as a command center for a force of demons charged by Demogorgon to protect
the lakes.

Azzagrat

Azzagrat is the realm of Graz’zt, an Abyssal lord. Azzagrat stretches over
three layers, the 45th, 46th, and 47th. Because all three layers are ruled by
the same Abyssal lord, they share many traits and have many portals connecting
them. One of the common threads among the three layers is the River of Salt,
a sparkling crystalline mass of liquid salt crystal. Needless to say, submersion
in the river is deadly. Other features include portals between the three layers
that appear as groves of viper trees and ovens of green fire. But given Graz’zt’s
cruel sense of humor, some green-fire ovens are simply full of fire and don’t
contain portals at all. The environments of the three realms are not terribly
dangerous; each resembles a twisted version of the Material Plane. For instance,
the 45th layer is like a constantly gray, rainswept steppe. The 46th layer is
illuminated from the ground, so that shadows are strange and rise like columns
of darkness into the sky. The 47th layer (only reachable from the previous two
layers, never from the Plain of Infinite Portals) is lighted by a blue sun.
Here flames are purple instead of red, and they deal cold damage. Thus, creatures
normally immune to fire might be surprised when they approach the flames.

Zelatar: The largest city of Graz’zt’s realm,
Zelatar exists in all three layers. Doorways may allow exit onto a street or
into a building, but the building interior or the street could very well exist
on a different layer of the Abyss. The inhabitants of Zelatar (demons, half-fiends,
tieflings, and others who revere Graz’zt) soon learn the ways of the shifting
portals, but most visitors require a guide to get from place to place within
the city. The Argent Palace is visible from anywhere in Zelatar, regardless
of which layer the observer is looking from. The Argent Palace is Graz’zt’s
abode of sixtysix ivory towers and one hundred cold, mirrored halls. The palace
is a sterile, echoing space where those seeking Graz’zt’s audience room must
wend their way through the mirror and portal maze in which ravenous bodaks roam.

Thanatos

Thanatos is the 113th layer of the Abyss. It is a cold layer
of ice, thin air, and dreary moonlit sky. The layer belongs as much to the undead
as to the tanar’ri—in fact, the layer has the minor negative-dominant trait.
Still, fiendish mosses and fungi grow on the edges of crusty tundra. Tombstones of every imaginable and unimaginable type dot the frozen landscape,
sometimes standing alone and sometimes grouped haphazardly as if in a small
cemetery. Undead range everywhere.

Naratyr: Nararyr, called the City of the Dead,
is a cold realm carved into the surface of a frozen ocean. Naratyr’s icy architecture
is a frigid necropolis of tall mausoleums, towering funeral obelisks, crypt
parapets, and carpets woven of hair removed from the thousands of unquiet dead
that reside in Naratyr. The city’s warlike legions include retrievers, vampiric
giants, and liches of all varieties. The rank and file of the population is
mostly zombies, ghouls, wights, and other decaying corpses that move with a
dark purpose. Who rules Naratyr? A good question. For time out of mind, a powerful
demon lord named Orcus claimed the entire layer. However, Orcus was recently
declared dead. A drow deity of vengeance and undeath claimed the victor’s spoils
and assumed control of the layer and its crowning jewel, Naratyr. But now there
are strong clues that Orcus is not quite as dead as many had thought. The drow
deity has disappeared, and no one knows whether she fled or was slain. Could
it be that Orcus once again rules icy Thanatos, one bony hand clutching his
terrible rod?

Other Abyssal layers

No tome could hope to catalogue the innumerable Abyssal layers.
However, a few interesting layers are described below. Other realms controlled
by the many demon princes also abide in the Abyss. Intrepid explorers who care
little for their lives may discover them.
Realm of a Million Eyes: The 6th layer of the
Abyss is home to the Great Mother, whom beholders revere. The realm is a network
of countless twisting tunnels, and living eyes stud the tunnel walls like encrusted
gems. In fact, each eye on the wall is an eye of the Great Mother.
Beholders and beholderkin of particular piety roam the eye-studded tunnels,
preying on one another as well as any demons or other visitors who might accidentally
fall from the Plain of Infinite Portals.

Ice Wastes: The 23rd layer of the Abyss is a
bitterly cold plane of miles-deep ice, devoid of most life. A distant sun no
brighter than the Material Plane’s moon lights this plane. The Ice Wastes are
the province of frost giants who serve Kostchtchie, their demon prince. Frost
giant mages dwell with their prince in the Glacier Citadel, a fortress carved
into the creaking ice between two towering peaks. Spring never comes to the
Ice Wastes, and most of its inhabitants live in underground strongholds or caverns.

Demonweb Pits: The 66th layer of the Abyss is
home to Lolth, the Spider Queen. The plane folds in upon itself so that it resembles
a great web. A dizzying array of web tunnels interconnect with fractal complexity.
Each strand is strung with portals onto the planes where Lolth is worshiped.
Lolth’s palace is said to be a mobile iron stronghold shaped like a spider,
perpetually crawling across her planar web.

Smargard: The 74th layer is home to Merrshaulk,
the yuan-ti deity. It is a realm of ever-shifting colors, moist jungles, acid
rain, and fermenting poisons. There may be no jungle floor at all, just layer
after layer of darker and dimmer forest canopies.

Abysm: The 88th layer of the Abyss, called the
Brine Flats, is home to Demogorgon, one of the most powerful demon princes.
It is a realm of briny water and rocky prominences used as rookeries by flying
demons. Aboleths, kraken, and demonic manta rays war in the depths, but all
bow before Demogorgon’s might. Here, Demogorgon has his terrible palace, called
Abysm. The portion of Abysm above water takes the form of two serpentine towers,
each crowned by skull-like minarets. Here, Demogorgon wields his arcane might,
attempting to induce the very Abyss to vomit forth its secrets. The bulk of
his palace extends deep underwater, in chill and darkened caverns that have
never seen light. The demon prince hoards his strength, only rarely involving
himself directly in the Blood War. His designs go far deeper.

Slime Pits: The 222nd layer is home to both
Juiblex, the Slime Lord, and Zuggtmoy, the Lady of Fungi. The layer is a bubbling
morass of oozing, fetid sludge called the Amoebic Sea. Vast expanses of caustic
slime engender strange life forms, sometimes by the will of the demons who reside
here, but sometimes spontaneously.

Fortress of Indifference: The 348th layer is
a lonely, blasted plain of tumbled rocks, jagged pinnacles, and sinister gorges
devoid of natural life. Crimson clouds scrub scrub the sky, and freezing winds
lash a traveler’s eyes and skin. Here stands the Fortress of Indifference, a
single 200-foot-tall tower of black iron gridwork. Humanoids of every variety
are woven into the metal itself, used as a ghastly mortar. Most of the forms
are dead, but many are undead and constantly wail and claw at the air. The Fortress
houses outcast demons, half-fiends, and tieflings. Though these creatures are
evil through and through, they have turned their backs on the Blood War. A nalfeshnee
demon named Tapheon rules the Fortress. Tapheon’s form is horribly scarred,
and he constantly wears a body-brace of rusty iron that keeps his bloated form
upright with long hooks. Tapheon’s favorite toy is a magic rod called the Despoiler
of Flesh, fashioned from sewn-together tongues. With it, the nalfeshnee can
alter any creature’s shape to any other shape the imagination can provide. Of
course, the imagination of a demon is a foul thing, and the rod brings the ghastliest
things to life.

Noisome Vale: The 489th layer of the Abyss was
once ruled by a powerful balor called Tarnhem, though he has gone missing. The
layer’s atmosphere is a haze of acidic gas constantly regenerated by volcanic
vents that scar an utterly blasted landscape. A ravine cuts through the landscape
of the Noisome Vale, but it is not filled with water or even condensed acid.
Instead, it channels a flood of slick, writhing worms that vary in length between
1 inch and 10 feet. These worms inhale the sulfur fumes endemic to the layer
and exhale breathable air. The worms’ respiration affects both shores of the
river to a distance of 50 feet on either side, effectively scrubbing the air
free of sulfur gas. Tarnhem’s manor is built along the ravine. Thanks to the
worms, it possesses a breathable atmosphere, though the constant susurrus of
the writhing worms below is maddening. Tarnhem’s demonic staff still maintains
the manor despite the absence of Tarnhem himself (the staff believes he is imprisoned
offplane). Despite Tarnhem’s disappearance, the demons that guard the manor
still take a dim view of unannounced visitors.