Dungeon Master's Guide

Finally, a creature can use an action to make an
Intelligence check to stabilize a spherical area centered
on the creature. The DC depends on the radius of the
sphere. The base DC is 5 for a 10-foot-radius sphere;
each additional 10 feet added to the radius increases the
DC by 5. On a successful check, the creature prevents
the area from being altered by the plane for 24 hours, or
until the creature uses this ability again.
PANDEMONIUM
Pandemonium is a plane of madness, a great mass of
rock riddled with tunnels carved by howling winds. It is
cold, noisy, and dark, with no natural light. Wind quickly
extinguishes nonmagical open flames such as torches
and campfires. It also makes conversation possible only
by yelling, and even then only to a maximum distance
of 10 feet. Creatures have disadvantage on any ability
check that relies on hearing.
Most of the plane's inhabitants are creatures that were
banished to the plane with no hope of escape, and many
of them have been driven mad by the incessant winds
or forced to take shelter in places where the winds die
down until they sound like distant cries of torment.
OPTIONAL RULE: MAD WINDS
A visitor must make a DC 10 Wisdom saving throw
after each hour spent among the howling winds. On a
failed save, the creature gains one level of exhaustion.
A creature that reaches six levels of exhaustion while
on this plane doesn't die. Instead, the creature gains
a random form of indefinite madness, as described in
chapter 8, "Running the Game." Finishing a long rest
doesn't reduce a creature's exhaustion level unless the
creature can somehow escape the maddening winds.
THE ABYSS
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The Abyss embodies all that is perverse, gruesome, and
chaotic. Its virtually endless layers spiral downward into
ever more appalling forms.
Each layer of the Abyss boasts its own horrific
environment. Although no two layers are alike, they are
all harsh and inhospitable. Each layer also reflects the
en tropic nature of the Abyss. In fact, much of what one
sees or touches on the plane seems to be in a decaying,
crumbling, or corroded state.
OPTIONAL RULE: ABYSSAL CORRUPTION
A non-evil visitor that finishes a long rest in the Abyss
must make a DC 10 Charisma saving throw. On a
failure, the creature becomes corrupted. Refer to the
Abyssal Corruption table to determine the effects of
this corruption. You can substitute different corruption
effects of your own creation.
After finishing a long rest, a corrupted creature can
make a DC 15 Charisma saving throw. On a successful
save, the corruption effect ends. A dispel evil and good
spell or any magic that removes a curse also ends
the effect.
If a corrupted creature doesn't leave the plane within
ld4 + 2 days, its alignment changes to chaotic evil.
Casting the dispel evil and good spell on the creature
restores its original alignment.
ABYSSAL CoRRUPTION
dlO
Result
1-4 Treachery. The character gains the following flaw:
5-7
8-9
10
"I can only achieve my goals by making sure that
my companions don't achieve theirs."
Bloodlust. The character gains the following flaw:
" I enjoy killin g for its own sake, and once I start,
it's hard to stop."
Mad Ambition. The character gains the following
flaw: " I am destined to rule the Abyss, and my
companions are tools to that end."
Demonic Possession. The character is possessed
by a demonic entity until freed by dispel evil and
good or similar magic. Whenever the possessed
character rolls a 1 on an attack roll, ability check,
or saving throw, the demon takes control of the
character and determines the character's behavior.
At the end of each of the possessed character's
turns, he or she can make a DC 15 Charisma saving
throw. On a success, the character regains control
until he or she rolls another 1.
IMPORTANT LAYERS
The layers of the Abyss are defined by the demon lords
who rule them, as the following examples illustrate.
More information about the demon lords can be found in
the Monster Manual.
The Gaping Maw. Demogorgon's layer in the Abyss
is a vast wilderness of savagery and madness known
as the Gaping Maw, where even powerful demons
go insane with fear. Reflecting Demogorgon's dual
nature, the Gaping Maw consists of a massive primeval
continent covered in dense jungle, surrounded by a
seemingly endless expanse of ocean and brine fiats. The
Prince of Demons rules his layer from two serpentine
towers, which emerge from a turbid sea. Each tower
is topped with an enormous fanged skull. The spires
constitute the fortress of Abysm, where few creatures
can venture without descending into madness.
Thanatos. If Orcus had his way, all planes would
resemble his dead realm of Thanatos, and all creatures
would become undead under his control. Under its
black sky, Thanatos is a land of bleak mountains, barren
moors, ruined cities, and forests of twisted black trees.
Tombs, mausoleums, gravestones, and sarcophagi
litter the landscape. Undead swarm across the plane,
bursting from their tombs and graves to tear apart any
creatures foolish enough to journey here. Orcus rules
Thanatos from a vast palace known as Everlost, crafted
of obsidian and bone. Set within a howling wasteland
called Oblivion's End, the palace is surrounded by tombs
and burial sites dug into the sheer slopes of narrow
valleys, creating a tiered necropolis.
The Demonweb. Lolth's layer is an immense network
of thick, magical webbing that forms passageways and
cocoon-like chambers. Throughout the web, buildings,
structures, ships, and other objects hang as if caught
in a spider's snare. The nature of Lolth's web creates
random portals throughout the plane, drawing such
objects in from demiplanes and Material Plane worlds
CHAPTER 2 I CREATING A MULTIVERSE