The Underdark

Tavern tales across Faerûn’s sunlit lands whisper of
the Underdark, a lightless, subterranean realm that
is home to fabled races and ancient, unspeakable evil.
It is a domain of primeval mysteries and unending war, a hidden
world of cruel masters and hopeless slaves, filled with monstrous
races that were old before humans were born. It is a dank, dismal
place of fungus, rot, and slime. It is a land where a few lucky merchants
have found a lucrative trade, but where many more have
been slain (or worse) for their effrontery. So dire is the reputation
of the Underdark and its denizens that mothers caution their
children to behave, lest the dark elves steal them away.

A proper account of the Underdark must include the cold
machinations of the hateful illithids, the unwholesome cities of
the drow elves who pay homage to the bitter Spider Queen, and the
unending servitude of the lesser creatures that fall into the
clutches of these two races. Unlike the upper world, where civilization
and the light of day protect travelers from horrors, the
Underdark holds the promise of deadly peril. Illithids, drow, phaerimms,
and aboleths vie for supremacy in its dark tunnels and sunless
seas. They fight one another with armies of slaves, terrible and
ancient magic, and mind-shattering psionics for control of the
encompassing tunnel systems and the extended caverns, vaults,
cavities, gaps, and nodes that riddle the earth beneath Faerûn. The
Underdark is literally an entire world, most of which is inhabited
by monstrous and evil creatures that shun the daylight. Hundreds
of independent cities, towns, and strongholds are scattered
throughout the caves and caverns that make up this realm.

Tunnels in the Underdark extend for miles, some ballooning
into caverns thousands of feet across, only to shrink to spaces too
narrow for a halfling to squeeze through. The largest cavern
halls are often representations of the surface in miniature, with
hills, valleys, underground rivers, and lakes. Most races native to
this realm make use of the walls and ceilings of their caverns,
accessing the higher levels via natural or magical flight or levitation,
or even wall-crawling mounts such as giant spiders and
certain breeds of lizards.

The Underdark is divided into three levels. The upper Underdark
(Upperdark) is close to the surface, and its residents have
considerable interaction with surface races. The inhabitants of
the middle Underdark (Middledark) tend to see surface races as
potential slaves. The lower Underdark (Lowerdark) is an incredibly
strange place filled with alien societies and bizarre cultures
hostile to those unlike them

Several races commonly found in other parts of
Faerûn—dwarves, elves, gnomes, and orcs—can be
found in the Underdark as well. However, the Underdark
versions of these races vary wildly from their surface-world
cousins—few would mistake a drow for a sun elf, a duergar for a
shield dwarf, or an orog for an orc.
The Underdark is also home to several races isolated by the
depths of rock that shield them from others or by the earthen
vaults in which they live. Their unique environments enable
them to thrive, or at least to eke out an existence not possible on
the surface.
Of the cousins to the common races, drow are the most
numerous in the Underdark. Several distinct ethnicities are represented
among the drow, though upperworlders and members of
most other races have a hard time telling one from another.
Surface-world dwarves sometimes impinge on the Underdark
in their excavations, but their deep cousins, the derro and the
duergar, are the true dwarvenkind inheritors of the Realms
Below. Encampments and communities of these two races are
found in almost every type of cave system or tunnel complex of
the deep earth.
Surface gnomes are rare in the Underdark, but their cousins,
the svirfneblin, dwell in great cities deep underground. The
svirfneblin do their best to keep the locations of their homes
secret from their enemies (the drow, the kuo-toas, and most especially
the mind flayers).
Planetouched also exist here and there in the Underdark.
Earth genasi in particular often ally with other humanoid races
against the monstrous mind flayers and aboleths.
Half-elves, halflings, humans, and surface elves are hardly
represented at all in the Underdark. However, rumors persist of
an Underdark human race, and those rumors have their basis in
truth: the ancient Imaskar empire has flourished in secret deep
below the earth for centuries.
Many even stranger Underdark races, including the chitines,
the grimlocks, the kuo-toas, the gloamings, and the slyths, are
also suitable as player characters for Underdark campaigns

What squelches through unlighted corridors
miles below the daylit surface
world? What secrets of ancient vintage
rest behind long-cooled barriers of solidified magma? What perils
and terrors await those foolhardy enough to venture into such a
dismal and dangerous environment? Adventurers from all over
Faerûn dare the depths of the Underdark in search of fame, fortune,
and power, but all too often they find only death—or fates
even worse than death.

Geology and
Environments
A cave is a natural opening in rock that is large enough for creatures
to enter. The Underdark, simply put, consists of a linked
network of several titanic cave systems. Large portions of it do
fit the definition of “a natural opening in rock,” but the Underdark
also encompasses areas of deep water that hide coral caves,
hollowed-out sections of ice in which creatures live, and places
where fungus, bone, or even pure force form “caves.”
Underdark terrain is dynamic and changeable. A map drawn
a few decades ago may show tunnels that have long since collapsed,
or lakes that are now dry. Terrain can change gradually
over the course of decades, centuries, and millennia, or swiftly as
a result of an earthquake or volcanic eruption.

Topography
The surface world is marked by mighty mountains, high
plateaus, and vast plains. The Underdark possesses none of these
features, but it does have physical features all its own. Unlike the
surface world, the Underdark is uniquely three-dimensional.
Knowing the direction of true north is not enough to navigate
the Realms Below; a traveler must also know the depth underground
of her destination. It is possible to find the correct coordinates
but still be several miles too deep or too shallow.
Many of the Underdark’s features can be explained as nothing
more than the results of purely physical forces, albeit sometimes
on a grand scale. Other features would be unlikely or even
impossible in worlds where magic, elementals, planar interstices,
and divine caprice did not help to shape the deep places.

ABYSSES
Vast, empty voids of awesome scope, Faerûn’s abysses are rare
features that can form insuperable barriers to travel. An abyss
is simply a great open space, sometimes many dozens of miles
in breadth and virtually bottomless. Some Underdark abysses
are scores of miles deep. The difference between an abyss and a
vault is difficult to define, but as a general rule, a vast space
approachable from its higher reaches is an abyss, while the same
space approachable from the floor might be better described as
a vault. Abysses tend to be larger and deeper than areas that are
considered vaults, but this is not always the case.
Like the starkest mountains of the Lands Above, abysses are
often completely impassable to anything without wings. Underdark
civilizations near such features sometimes carve out harrowing
ledge-paths to circle the tremendous void of the
neighboring abyss, or endless stairs to descend its walls.

CAVES
Perhaps the most common topographical feature of the Underdark,
a cave system consists of a series of caverns and passages
that may stretch for miles. Caves can be formed by several
different methods, but the most common is the action of flowing
water. Cave systems often twist, turn, climb, and drop in a
maddening fashion, forming three-dimensional mazes that
dishearten even the most determined mapmakers.
Caves vary widely in terms of their habitability. Living caves
that include streams or rivers are full of life (by Underdark standards)
and can often support surprisingly large populations, especially
of improbably large and ferocious monsters. Other caves
may be barren wastelands, without food or water.

DUNGEONS
Over the course of a hundred or more centuries, Faerûn’s deep
caverns and vaults have been expanded tremendously by the
delving of various Underdark races. Thus, the term dungeon
when applied to the Underdark means a structure excavated
from the surrounding rock by intelligent creatures. For example,
a great duergar city delved into the wall of a vault might be considered
a large dungeon, with halls and passageways extending
for miles from its entranceways. Dungeon complexes often serve
to link two natural features (such as two or more vaults close to
each other) with a system of artificial caves that vastly extends
the scope of a natural cave system.
Dungeons come in two varieties—abandoned and occupied.
Since they are not sources of food or water in and of themselves,
empty dungeons do not necessarily attract Underdark settlers.
However, dungeons are often supremely well suited for defense,
and a dungeon that happens to be near a rich area such as a
living cave is almost certain to be occupied by something, even
if the original builders are long gone.

GORGES
Just as on the surface, water can carve deep canyons and gorges
in the Underdark. An Underdark gorge is nothing more than a
cave that runs vertically instead of horizontally. Gorges often
feature streams (and therefore life and food), although the difficulty
of the terrain makes a gorge less desirable as a residence
than a living cave with less extreme topography.
Since gorges can run for many miles, they often serve as the
highways of the Underdark. Travel along the floor of a gorge
can be very difficult, but many Underdark races take steps to
improve these natural roads for the use of their own merchants
and hunters. Gorges also offer good opportunities to
change depth and perhaps access another level quickly, through
a little climbing.

LAKES
Water is common in the Upperdark, since runoff from the surface
frequently drains into cave systems belowground. In many
areas, the water table is close enough to the surface that only the
most shallow cave systems can form. However, due to the
unusual factors involved in the creation of Faerûn’s Underdark,
a water table 20 feet belowground does not necessarily mean that
air-filled caves don’t exist at greater depths. Planar connections,
particularly to the planes of Earth and Water, make very
unlikely hydrology possible.

Any body of fresh water is called a lake. Underdark lakes
range in size from small pools to inland seas hundreds of miles
in extent. Large lakes typically occupy either tremendous vaults
or connected networks of partially submerged caves. The Lake
of Shadows and the Giant’s Chalice are examples the former
type, and the Darklake is an example of the latter. If a lake has
both an inlet and an outlet, its water is usually drinkable, but
lakes that are not refreshed from time to time may stagnate.
Most lakes are found in the Upperdark or Middledark. Bodies
of water that collect in the Lowerdark simply can’t drain to any
lower elevations, so they tend to be seas (brackish water) instead.
However, planar connections to the Elemental Plane of Water
mean that at least a few of the bodies of water in the Lowerdark
hold fresh water.
Large lakes can form the best and most accessible highways
of the Underdark. In many places, however, the cavern ceiling
descends to meet the water, making the lake impassable to all but
aquatic creatures.

RIFTS
Unlike gorges, rifts are not formed by erosion. Rather, they are
the scars of tremendous upheavals deep in the earth. Rifts are
places where vast blocks of stone rose, sunk, or slid past one
another in long-ago cataclysms, leaving tremendous chasms.
Rifts may be dozens or even hundreds of miles in length, and
sometimes miles deep, but they are rarely very wide—most are
less than a bowshot across.
Rifts sometimes break apart preexisting features such as cave
systems, presenting formidable obstacles to creatures traveling
through caves. In order to continue when faced with a rift, the
traveler must climb or descend to the appropriate level on the
far side. Like gorges, rifts often serve as vertical highways in the
Underdark, offering travelers the opportunity to change depth
with little fuss.

RIVERS
Underdark rivers tend to be swift, violent, and tortuous in their
windings. It is a rare river indeed that flows level and smooth for
more than a few miles at a time before disappearing into a deep
gorge or sinkhole in a fuming waterfall. Rivers are the great
builders of the Underdark, the natural force that sculpts great
caverns and brings lifegiving energy and food to sustain the
Underdark ecology. Most rivers are surrounded by a halo of
living caves, which can be valuable real estate indeed.

SEAS
Perhaps the most wondrous of the Underdark’s features are the
vast, nighted seas of the deep earth. Seas are saltwater bodies, not
fresh, and most of them are found in the Lowerdark, though
Underdark seas also occur at higher spots beneath Faerûn’s surface
oceans. While air-filled cave systems may extend for dozens
or even hundreds of miles beneath the oceans above, or form airlocked
siphons of extraordinary size, these features are exceptional.
Most caves beneath large bodies of saltwater are simply
subterranean extensions of surface oceans.
Seas tend to form in the largest of vaults, occupying caverns
large enough to be miniature worlds in their own right. Like the
lakes, seas offer some of the best roads in the Underdark, and
many are heavily traveled.

SHAFTS
Sometimes natural processes form deep pits or wells in the earth.
The shaft of such a structure may be carved out by water flowing
straight downward in a subterranean waterfall, or created by
volcanic activity. Unlike a gorge or a rift, a shaft tends to be a
relatively small feature (usually less than a bowshot in diameter),
but it may plummet for miles straight down.
Because of their relatively small cross-sections, shafts often
serve to channel air movement between disparate portions of the
Underdark. In places where the conditions are extreme (for
example, a shaft near a superheated magma chamber), the air
movement can also be extreme. Screaming winds might roar up
or down a shaft in a scouring blast that would put a hurricane to
shame. Sometimes, cave systems “breathe” in conjunction with
changes in the surface world above, resulting in tremendous
rushes of wind in and out through shafts every day.

TUNNELS
A tunnel is simply a passage that connects one place with
another. Most are cut by creatures, though some are the results
of natural movements of the earth and other forces. Underdark
races often cut very ambitious tunnels to link multiple cave systems.
Though such dreary passageways may be dozens of miles in
length, most are only 10 or 20 feet across. Other tunnels are the
work of burrowing monsters such as delvers, purple worms, and
umber hulks. These “natural” tunnels may be twisting, turning
mazes of intersecting passages.

Tunnels are some of the Underdark’s most useful roads, but
they severely restrict a traveler’s options. If you don’t like where
a tunnel leads, you really have no choice but to go back the way
you came. Tunnels also offer few hiding places for those who
cannot blend in with stone, so often the only way to get away
from a predator is to run—and hope you’re faster.

VAULTS

The higher reaches of the Underdark consist of immense networks
of relatively small caves, but as a traveler descends, the
number of caves decreases while the size of the individual caves
increases. A large cave near the surface may consist of a few
dozen linked chambers, each perhaps a few hundred feet long
and a few dozen feet wide. But deeper down are openings in the
earth that dwarf any surface dweller’s conception of a cave.
A typical vault may be 2 to 4 miles across and as much as 1
mile high. Some, however, sprawl for 50 miles or more and reach
heights of 5 or 6 miles from the floor. Larger vaults often feature
immense columns—huge piers of natural rock that help to
buttress the soaring ceiling. Some were formed by unthinkably
massive pieces of the world grinding past each other in the very
dawn of time, others by the influence of the Underdark’s native
magic, and still others by the confluence of planar characteristics
in buried planar connections. However it was formed, a vault
is a world in miniature, with its own streams, lakes, hills, and
plateaus all contained in a single vast cavern.

Vaults are almost always highly desirable territories, since
they usually offer enough space and resources to support huge
forests of fungus, moss, and other strange growths. By Underdark
standards, most vaults teem with life, so it comes as no
surprise that they support the most powerful and numerous
of Underdark settlements. Some stories even tell of illuminated
vaults, places where sun-bright crystals in the ceilings blaze
with the intensity of true daylight and support green plants and
surfacelike fauna in abundance.

VOLCANOES
It is not universally true in Faerûn that descending 40 or 50
miles straight down in any spot brings a traveler to magma. Volcanic
activity is extremely variable in the Underdark. Isolated
pools of magma seep up almost to the surface in all sorts of
places without any other volcanic activity, and in other places
deep tunnels and vaults support humanoid settlements at depths
where magma should be all that’s present. Again, planar anomalies,
deific intervention, and the powerful magic of the earth
itself are likely to blame. Whatever the cause of these surprising
conditions, racing rivers of molten rock, caverns full of brimstone
and sulfurous reek, and scalding geysers and hot springs
can be found at almost any depth in the Underdark. Underdark
volcanoes aren’t really mountains—they are usually tremendous
fissures or magma chambers that can vomit deadly rivers of lava
into nearby caverns with little or no warning.

Faerzress and the Underdark

Many parts of the Underdark of Faerûn are suffused with a
magical radiation that the drow call faerzress. A remnant of
the mighty forces that originally shaped the terrain of the
Underdark, faerzress distorts and interferes with certain types
of magic.

The effects of faerzress on spells are not widely known
among surface-dwelling characters. Before a spellcaster attempts
a spell that would be affected by the Underdark’s magical conditions,
a DM may allow the character a DC 20 Knowledge
(arcana) or Knowledge (local) check to determine
whether he or she happens to know about the hazards.

Areas of faerzress can be found here and there throughout
the Underdark. The drow have long sought out places of powerful
faerzress in which to raise their cities, since the magical radiation
helps to frustrate spying and protect against enemy
assaults. The magical energy can also be used in the construction
of various powerful magic items.

Faerzress has the following effects:

Divinations: Every creature in an area affected by faerzress
receives a +4 bonus on Will saves against all divination spells,
including scrying and greater scrying spells.

Teleportation: Spells of the conjuration (teleportation) subschool
do not work reliably over distances greater than 1 mile
when either the origin or the destination is within an area
affected by faerzress.

A character who casts a teleport spell or uses an ability or
item that duplicates that effect must make a Spellcraft
check (DC= 25+1 for each mile traveled). Success indicates that the spell works properly; failure
means that the teleporting character automatically suffers a
mishap, just as if he or she had rolled 100 on the table in the teleport
spell description, followed by an “off-target” result.

A character using a normally infallible form of teleportation
magic (such as word of recall or greater teleport) must also make
a Spellcraft check(DC= 25+1 per 10 miles traveled). Again, success indicates that the spell
works properly, and failure means the character suffers a mishap
and an off-target result, as described above.

Portals

Portals are a primary means of transportation into, out of, and
through the Underdark. Individual portals, pairs of portals, and entire
portal networks make nonlinear travel possible in many portions of
the Realms Below. To reach a cavern 100 miles away, a traveler
might make use of a portal that leads to a distant rift thousands of
miles away, travel a dozen miles to reach a different portal network,
and then take a different portal to the desired destination.
Sometimes portals provide handy shortcuts past blocked or
dangerous tunnel systems, but portal routes aren’t always safer
than the mundane routes they replace. Some portals lead to different
planes or horribly dangerous places, for reasons known
only to their creators.

Along major travel or trade routes in the Underdark, portals
are clearly marked by archways, columns, or piles of stones.
Carved or painted graffiti often adorns the area around a portal,
frequently providing cryptic information about either the portal
itself or the inhabitants and environs on either side.

ADDITIONAL PORTAL QUALITIES

Portals with different qualities fulfill different species’ needs.
Some portals constructed in the Underdark were made specifically
to address the requirements of nearby inhabitants.
Light-loving races in the Underdark favor transparent,
impassable portals that open out to normally sunny vistas in the
Lands Above. Such a portal allows sunlight to filter through
without the oppressive heat.

In arid areas of the Underdark, a small, limited use, nonliving-
only portal to the Elemental Plane of Water may provide
the only source of water for miles. Such a portal could supply a
thriving humanoid settlement, complete with herds of rothé
and fungus fields. Destroying it would endanger many lives, and
creatures that rely so heavily on a portal for their sustenance
typically guard it heavily.

Other, stranger portals defy explanation. For example, a nonliving-
only portal in one cavern near Fingerhome frequently lets
in snow from an area high in the Spine of the World.
Impassable: A portal with this feature acts as a window to
another place but does not allow passage. Impassable portals can
be created at no extra cost.

Nonliving-Only: The opposite of creature-only portals, nonliving-
only portals transport only inanimate matter. This feature
supersedes the general rule of portals stating that unattended
objects cannot pass through a portal. Making a portal nonlivingonly
quadruples its cost.

Transparent: A transparent portal looks much like a regular
doorway opening. Such a portal can be transparent only in the
direction of travel, so a single portal that affords only unidirectional
travel is transparent from its origin to its destination, but
there is no visible effect at all at the destination point. Making
a portal transparent adds 50,000 gp to its cost.

PORTAL SEEPAGE
A newly created portal functions well and sustains a solid barrier
between its origin and destination points. As centuries or millennia
pass, however, a portal can decay or malfunction (see FORGOTTEN
REALMS Campaign Setting for information on malfunctioning
portals). In addition to malfunctions, portal seepage may occur in
older portals. When this phenomenon occurs, qualities of the
portal’s destination side start to soak into its origin side.
When a portal seeps, the planar traits described in Chapter 5
in the Dungeon Master’s Guide begin to affect the surrounding
area. The rate can vary, but the area covered by the seepage
averages a 5-foot radius around the portal per 100 years of age.

An Underdark
Primer
While many surface dwellers regard the Underdark as all the
same (one big cave, infested with hungry monsters), the wise
adventurer prepares by studying what surface dwellers know
about the Realms Below before venturing underground. Knowing
what sorts of creatures and dangers lurk at what depths
might mean the difference between life and death.
The Underdark is divided into three general levels: The
Upperdark, the Middledark, and the Lowerdark.

The Upperdark
The Upperdark extends from the surface to a depth of about 3
miles. Varied races inhabit this region, including chitines, drow,
dwarves, giants, all manner of goblinoids, orcs, svirfneblin, and wererats.
Scouts from deeper races often venture into the Upperdark
in order to trade with (or prey on) the races native to this area.
The Upperdark’s main import from the surface is slaves.
Slavers from evil-aligned cities in the Upperdark make frequent
forays into the light to capture new slaves for use as either labor
or food. They also trade for textiles, grains, fruit, and weapons.
Their exports include raw ore, refined metals, gems, and native
Underdark plants.

Travel in the Upperdark is relatively easy. Multiple paths to a
single point usually exist, thanks to millennia of natural processes,
volcanic activity, burrowing creatures, and various races cutting
trails through the rock. In most places the surrounding earth is
composed of rock, but near the surface, tunnels can be hewn out
of tightly packed dirt, allowing creatures with burrow speeds that
can’t cut through rock to blaze their own trails in a pinch.

SURVIVING IN THE UPPERDARK
Survival checks made to hunt, forage, and avoid natural hazards in
the Upperdark use the same DCs as normal surface conditions. Basic
amenities such as light, air, food, and water are less available in the
Upperdark than on the surface, but they are common enough.
Luminescent flora and faerzress provide occasional light,
though not consistently enough to allow a creature without darkvision
to travel without an independent light source. Vents from
the surface keep air fresh and moving in the passages, so air quality
is rarely an issue. Enormous underground lakes spread across
hundreds of miles in some regions, and water trickles down from
the surface in many others. Many water sources are guarded or
fouled, but quite a few are both clean and open for anyone to use.
Many different types of wild fungi are edible, and the Underdark
equivalent of small game (rats, dire rats, lizards, and giant
vermin) can easily be found in the tunnels. Domesticated
animals, such as deep rothé, can also be found near most major
population centers.

DENIZENS OF THE UPPERDARK
Most Upperdark inhabitants traffic with the surface world in
some way, either trading with or raiding their upstairs neighbors
for things they can’t get in their native habitat. They also trade
with (and raid) each other. No Underdark community is ever
really friendly with another, but Upperdark settlements often
observe wary truces with their neighbors.

Chitines: Though they are sometimes considered too small,
weak, or fearful to matter, chitines are quite capable of killing
those who underestimate them. They are far more clever and
malicious than they seem to be—clever enough to avoid fights
they’re not sure they can win, at the very least. Chitine nests can
be found in web-filled caverns throughout the Upperdark, but
the largest concentration of these spiderfolk is the realm of
Yathchol in the northern Underdark.

Dwarves: For thousands of years, the great dwarven realms
of the surface world have expanded downward instead of outward.
Neither gold dwarves nor shield dwarves harbor any fear
of the Underdark, and their cities are often buried in the upper
reaches of the Realms Below. The kingdom of Iltkazar is the
strongest shield dwarf realm remaining in the Underdark, and
the gold dwarves there retain extensive Underdark holdings in
the vicinity of the Great Rift.
Unlike the duergar, who prefer the deeper portions of the
Underdark, gold and shield dwarves keep fields and livestock on
the surface and trade extensively with surface folk. These
dwarves are gifted engineers and industrious workers, and they
have built many roads and bridges in the Underdark.

Goblins: Bugbears, goblins, and hobgoblins often establish outposts
and settlements in the Upperdark, from which they can
easily raid nearby surface lands. Goblinoids may in fact be the
most numerous of the Underdark’s races, but they have raised no
great cities and delved no great caverns. Most goblinoid tribes
exist in a state of barbaric squalor.

Goblins in particular are commonly found as slaves in the
cities of crueler and more sophisticated races, such as the drow
and the duergar.

Quaggoths: These so-called deepbears frequently band
together to raid and forage throughout the Underdark. They
once had a kingdom, Ursadunthar, deep beneath the Spine of the
World, but it fell to the duergar of Gracklstugh in –1350 DR.
Most quaggoth bands now survive by roaming the deeps as
nomadic hunter-gatherers and supplementing their diets with
anything (or anyone) that falls into their bloody claws.
Like goblins, quaggoths are frequently encountered as slaves
in the cities of more civilized Underdark denizens, such as drow.

Minotaurs: Hulking and fierce minotaurs dwell in the Upperdark,
usually favoring the most confusing and complex cave systems
for their lairs. Minotaurs generally live by raiding and
plunder, although more than a few sell their services to other
folk who offer gold and food in exchange for a chance to fight.
Minotaurs are kept as slaves by Upperdark dwellers such as drow
and mind flayers, but such slaves are not numerous.
The vast delve known as the Labyrinth was once a minotaur
empire of sorts. While no signs of the former minotaur civilization
remain, thousands of the creatures still infest the area.

Orcs: Like goblins, orcs often settle in the upper caverns of
the Underdark. Caverns close to the surface offer shelter from
the hated sun and easy defensibility with a minimum of work,
and most orcs are only too happy to take advantage of that
combination. Orcs are often enslaved by deeper-dwelling races,
so they can be found almost anywhere in the Underdark.

Svirfneblin: The deep gnomes live in hidden caves and secretive
strongholds throughout all three layers of the Underdark,
but most of them dwell in the Upperdark and Middledark. Deep
gnomes avoid trouble by simply staying well clear of it, and few
strangers ever blunder across svirfneblin towns.
The svirfneblin city of Blingdenstone fell recently to a
demon-spawned drow assault.

Stone Giants: Powerful and ponderous in action and thought,
stone giants are strong enough to keep all but the most magically
powerful of foes at bay. These creatures delve enormous
quarries for their homes, and they can work wonders with their
chosen medium.
Few in number, stone giants leave other folk alone and
expect the same courtesy from anyone passing through their
lands. The most powerful stone giant realm is the kingdom of
Cairnheim, beneath the Giant’s Run Mountains.

Troglodytes: Perhaps no other race is as universally detested
as the troglodytes. These bloodthirsty savages descend on the
realms of other Underdark folk like a plague of locusts and
immediately set about raiding, pillaging, and killing anyone
unfortunate enough to be nearby. They occasionally serve as
slaves to more powerful races, but only in those places where
more tractable (and less vile) slaves aren’t widely available.
Troglodytes were once much more widespread in the Underdark
than they are now, but they have been rooted out and exterminated
in many places. Most troglodytes now live in the
southern portions of the Underdark, particularly beneath the
Mhair and Black Jungles.

The Middledark lies between 3 and 10 miles beneath the surface
of Faerûn. Most larger cities of drow and duergar are in the Middledark.
Other inhabitants include lone aboleths, cloakers, derro,
grimlocks, and kuo-toas. A few mind flayer outposts are scattered
throughout this level as well.

Settled communities in the Middledark commonly send trade
caravans and raiding parties to the surface, or at least up to
Upperdark trading centers such as Menzoberranzan and Ooltul.
Visitors from the surface are rare and tend to be viewed as
potential slaves or food. Caravan travel brings mostly luxuries;
staples must be grown locally.

Travel in the Middledark can be difficult. In many cases, it’s
simply not possible to go from one place to another because no
caves or tunnels lead in the right direction. To overcome this
drawback, many of the races that dwell at this depth are prolific
portal builders and tunnelers.

SURVIVING IN THE MIDDLEDARK
The Middledark is, at its best, worse than the harshest surface
deserts. The DC for any Survival check made in the Middledark
automatically increases by 5, even for natives. Wild resources are
hard to find, and most of those that do exist have already been
placed under guard by someone else.

Glowing fungi and lichens are less common at this depth than
they are in the Upperdark. They can be easily cultivated, but
most concentrations of them appear in cities, not in the wild. Air
tends to be stale, but breathable, though poisonous fumes choke
out normal air in a few areas. In many places, water is scarce, and
any large supply is well guarded. Creatures living at this depth
get most or all of their water from the fluids in other creatures
they eat. Food is the most plentiful of the necessities at this
depth, but even that becomes an issue at the lower end of the
depth range.

DENIZENS OF THE MIDDLEDARK

No alliance is permanent in the Middledark. Some communities
maintain wary trading partnerships with others, but it is understood
that if one party ever grows stronger than the other, the
terms of the partnership will change—perhaps drastically. Even
in the most open of Middledark cities, newcomers can expect to
be challenged (physically or otherwise) unless they make a
pointed display of power upon entry.

Drow: Most drow cities occupy large vaults or caverns in the
Middledark. At these depths, faerzress is common and powerful,
and the dark elves have developed many potent spells and
defenses that harness the Underdark’s magical radiation for
their own purposes. The Middledark also offers the defense of
distance—a drow outpost near the surface is vulnerable to the
attacks of adventurers and surface elves, but moving a large
army into the Middledark can’t be done with ease.

Taken as a whole, drow probably have the most significant
presence in the Middledark. Their cities and strongholds are
numerous, wealthy, and well situated for defense, and the drow
themselves are cruel and strong. Only the endless feuding of the
great Houses constrains drow power. Menzoberranzan is the
most famous of drow cities.

Duergar: The Middledark is also home to the largest and
The duergar have no particular
use for faerzress and do not worry about ages-old vendettas
against the surface world; they came down to the Middledark
because the lower one descends into the earth, the more rare
and wondrous the minerals that one can find. If the Lowerdark
were not so completely inhospitable, the gray dwarves would
pursue their veins of ore and gemstones all the way to the roots
of the world, but lower reaches of the Middledark represent the
deepest depth at which large cities can be easily sustained.
Duergar cities are less numerous than those of the drow, but
any given gray dwarf city is likely to be a strong, wealthy, and
martially inclined realm quite powerful enough to deter the
attacks of its hostile neighbors. The cities of Dunspeirrin and
Gracklstugh are good examples of duergar realms.

Fomorians: The most hideous and wicked of giantkind, the
terrible fomorians dwell throughout the Underdark, but mostly
in the middle section. They are thankfully scarce, and no one
knows of any true fomorian cities of holdings in the Realms
Below. However, a few dozen fomorians gathered in a keep or
clanhold represent a formidable threat to their neighbors.

Grells: Monstrous and alien, grells are usually thought of as
solitary predators, but in the Underdark they have been known
to gather in nests or hives numbering dozens of individuals. In
settlements of this size, grells divide themselves into distinct
castes, including a philosopher caste whose members boast potent
abilities as psions or sorcerers. Grells make poor neighbors, since
they regard all other creatures only as potential prey.

Grimlocks: Well suited for a life in the lightless depths, grimlocks
gather in large, savage tribes that are fully capable of overwhelming
the cities and strongholds of more sophisticated races.
Grimlocks are tireless hunters and raiders, and they often range
dozens of miles from their lairs in search of food and plunder.
Like the goblins and orcs of the higher levels, grimlocks are frequently
enslaved by other races (particularly mind flayers) and
can be found almost anywhere.
The grimlocks long ago laid claim to the cavern complex
called Fingerhome. Within it, the village of Reeshov is a good
example of a community of free grimlocks, as is the Cavern of
Cloven Heads, which is home to the twisted descendants of the
Golden Eagle and Red Pony Uthgardt tribes.

Hook Horrors: These vile abominations plague many of the
Middledark’s lonely and deserted passages, waylaying any travelers
who come along. Hook horrors seem barely sentient, but they have
been known to gather in large and dangerous bands to stake out a
good source of water or a cavern of edible fungus as their own.

Kuo-Toas: Kuo-toas are found throughout the seas of the
Middledark. This once great race has dwindled over time, and
many of kuo-toan cities lie in ruins. The worship of the Sea
Mother is all-important in kuo-toan society, and kuo-toa clerics
and monks wield virtually unchallenged power over the rest of
the race. Kuo-toas get along reasonably well with most other
Underdark races (except aboleths), and they travel widely as
traders, pilgrims, and guides.
The strongest kuo-toan city remaining in Faerûn’s Underdark
is Sloopdilmonpolop, which lies in Old Shanatar. Kuo-toas
generally keep to the saltwater seas of the Underdark, leaving
the freshwater lakes to the aboleths.

Maurs: Like the stone giants or fomorians, maurs are not
common, but where they walk, lesser folk get out of the way.
Descendents of storm giants that were imprisoned deep in the
earth long ago for some forgotten crime, maurs are unusual
among Middledark races in that they are not malicious, predatory
slaveholders. Some maurs are as wicked as any fomorian, of
course, but for the most part, these ruined giants want nothing
more than to be left alone by their neighbors.

Mind Flayers: After the drow, the mind flayers are probably
the most powerful, notorious, and sinister of the Underdark’s
peoples. Illithid cities tend to be quite small by the standards of
other races—few of them number more than 500 mind flayers.
However, since illithids are uniquely well suited to hold great
numbers of slaves and thralls, mind flayer cities may have ten
times as many slaves as illithids. Unlike the slaves of the drow or
duergar, illithid thralls are compelled to absolute loyalty and
zeal in the service of their horrid masters. The mind flayers can
field entire armies of thralls whenever they wish and hurl them
into battle without concern for their loyalty or fighting spirit.
The mind flayers prefer the lower reaches of the Middledark,
but they also have numerous communities in the Lowerdark.
The mighty city of Oryndoll is the most famous of their realms.

Orogs: Stronger, smarter, and more advanced than their surface
kin, the deep orcs are well suited for the fierce competition of the
Underdark. Orog cities are not numerous, but they can be found
throughout the northerly reaches of the Underdark, from the
Spine of the World all the way to the Icerim Mountains. Orogs
favor volcanic regions, so they tend to found their cities in torrid
caverns too hostile for creatures without fire resistance to endure.

Umber Hulks: Although umber hulks are sentient, they are
nomadic hunters that build no cities and manufacture no tools.
Their claws and mandibles are more than sufficient for their purposes.
Among the most common of the Underdark’s monsters,
umber hulks fearlessly attack almost anything they meet, relying
on their confusing gaze to scatter or paralyze most of their foes.

No place on Toril is as strange and dangerous as the Lowerdark.
This level of the Underdark extends from 10 miles below the surface
to unfathomable depths and features a degree of strangeness
that would drive some surface dwellers insane. Few upperworlders
ever descend to the Lowerdark, and few of the Lowerdark’s
denizens want anything to do with the surface world.
Some of the creatures in the Lowerdark—intelligent or otherwise—
aren’t even aware of a surface world; others have heard of
it but consider it a mythical place.

Interspecies and intraspecies strife is the rule in the Underdark.
Resources are minimal, and weakness invites extermination.
Most of the Lowerdark’s denizens are chaotic, evil, or both.
Even the vermin and animals encountered in this area are rarely
ordinary—many have been transfigured by crossbreeding or
magical interference. Nothing here is normal or simple.
Travel in the Lowerdark is arduous at best. The term Lower
Underdark actually refers to many places, since the great domains
of Faerûn’s Underdark possess fewer and fewer interconnections
the deeper one delves. Only about a third of the lowest sections of
the Underdark actually connect to each other. The rest of the
Lowerdark consists of isolated pockets of space reachable only
from the Middledark, by water, or by transportation magic.

Typically only one route exists to any given point, and that
is what must be used unless the traveler plans to dig one. Though
time consuming and cumbersome, many adventurers find it expedient
to do just that, so they keep the necessary magic items and
spells handy to make their own tunnels as needed. Fortunately,
faerzress is rare at this depth, so teleportation can be used to
travel the Lowerdark with a reasonable hope of success, assuming
that the traveler has a good sense of the destination.

SURVIVING IN THE LOWERDARK

The Lowerdark is a strange realm warped by severe environmental
and magical forces. The problems that pervade the rest
of the Underdark intensify here. Resources are scarce, and control
of them is continually contested. Air does filter down this
far, but it is frequently stale and occasionally toxic because of
geothermal fumes. Water is virtually nonexistent, and the little
that is present is well guarded. Food cannot be found in the wild,
unless the hunter has no aversion to cannibalism. (Many creatures
at this depth survive by this means.) The Survival check
DCs for most tasks increase by 10.

Exacerbating these problems still further are numerous areas
of wild magic and dead magic. Though faerzress is rare here, the
Weave in the Lowerdark is a snarled, tangled mess. Yet another
magic-complicating feature is a high degree of portal seepage (see
Chapter 4).

The darkness at this depth is so deep that it seems to actively
dislike light. Natural light sources fail with unnerving frequency,
and magical light sources draw attackers like flies to rotten fruit.
In some places, the shadows cast in areas of light are unnatural—
too large or too small for the light source, or cast in contradictory
angles. Even beings with darkvision see a flickering of dark
around the edges of their vision, as if the darkness were trying to
drown out any sight at all.

DENIZENS OF THE LOWERDARK

Why would any creature with intelligence or common sense live in
such a terrible environment? Some races have lived here for generation
upon generation, and the Lowerdark is simply their home.
Other creatures settle here to take advantage of the Lowerdark’s
unique magical properties, rare ores, or shelter from the hated sun.
Still others view a sojourn in the Lowerdark as a temporary solution,
since the dead magic areas and hostile territory may be a
wanted criminal’s most expedient means of avoiding capture.
Of course, not everyone is in the Lowerdark by choice. Some
unfortunates are here because they neglected to research the
destinations of the portals through which they ventured.

Others have been exiled here from communities in the Middledark, the
Upperdark, or even the surface world. Some drow matrons get
rid of potentially problematic subordinates by sending them on
exploratory or expansionistic raiding parties into the Lowerdark.
A triumphant scout returning from the mission into the depths
might find her unexpected survival fatally inconvenient to the
matron who dispatched her.

Several Middledark races make frequent forays into the Lowerdark.
Some do so because of expansionistic desires, others
because they need the resources, and a scant few because they
have something to prove. Grimlocks and orogs often set a
coming-of-age trial for their young warriors to mark the passage
between adolescence and adulthood. In a typical version of such a
trial, the youth is sent into the Lowerdark, sometimes armed only
with a dagger, and told to return with a trophy demonstrating his
competence and ability to contribute to the community.
Aboleths: These horrible aberrations lurk in the deepest,
blackest waters of the Underdark, surrounded by legions of
thralls. Gifted with extraordinary intelligence and powerful
magical abilities, the aboleths are the unquestioned masters of
most Lowerdark lakes and seas. While some aboleth cities are
quite large, small outposts (or “broodholds”) of a dozen or so outposts
are much more common.

Avolakias: Thankfully few in number, the avolokias are master
necromancers and shapechangers. In its true form, an avolakia is
a 10-foot monstrosity combining insectile, octopoid, and wormlike
features. Devoted to the elevation of deities of decay and undeath
(including Ghaunadaur and Velsharoon, among others), an
avolokia nest is surrounded by a shambling army of undead under
the monsters’ control. Avolakias occasionally ally with aboleths or
mind flayers, but they regard humanoids of any sort as nothing
more than fodder for creating more undead.

Beholders: The Lowerdark is home to numerous beholder
hives. Each of these bizarre cities can house hundreds of eye
tyrants and thousands of slaves. Like mind flayers, beholders can
magically compel loyalty from their thralls, and they believe
that their natural role in the scheme of things is tyranny over
lesser beings. Some beholder hives experiment with breeding
strange servitor beholders to fill specific roles, but all eye tyrants
believe that the beholder form is perfect, and that any deviation
from it is monstrous. This attitude means that beholder hives
make implacable enemies when they decide to go to war.
The city of Xonox, beneath the Lake of Steam, is an excellent
example of a beholder realm.

Cloakers: Often encountered as small bands in higher portions
of the Underdark, cloakers gather into great convocations in a
few places in the Middle and Lower Underdark. These strange
and sinister creatures seem universally hostile to all other beings,
and their teeming cities are no place for travelers to visit.

Deepspawn: These horrible creatures give birth to monstrosities
of all sorts, surrounding themselves with armies of their
spawned minions. Deepspawn are found in all portions of the
Underdark, but the largest, most wicked, and most fecund of the
species seem to hail from the Lowerdark.

Derro: Murderous and cruel, the derro are found at all
depths of the Underdark. At the upper levels, they tend to live
in small bands within the cities of other races, such as the duergar,
fomorians, or kuo-toas. The true cities and strongholds of
the derro are buried deep in the Lowerdark. From time to time,
the derro muster their strength to fight great wars against all
other creatures in the Underdark, swarming up from their
hidden realms to plunder any realm unfortunate enough to lie
in their path.

Desmodus: The desmodus are perhaps the only denizens of
the Lowerdark that are actually good in alignment. The desmodus
do not gather in great cities or strongholds; instead they
live in small families and clans scattered throughout the Lowerdark.
Even with their generally benevolent outlook, however,
the desmodus do not take kindly to strangers raiding their food
stores or water supplies.

Destrachans: These eyeless terrors roam the Lowerdark in
hungry packs. Destrachans are the perfect Underdark predators.
With their phenomenal sense of hearing and their sonic attacks,
they are more than capable of stalking and slaying even well-armed
parties of drow or surface adventurers.

Elementals: Elemental creatures and creatures with elemental
heritage (such as genasi) generally do well in the Lowerdark.
In particular, earth elementals and dust, earth, and salt mephitis
find the deep underground to be an ideal environment. Fire elementals,
thoqqua, azer, salamanders and fire, magma, and steam
mephitis love Lowerdark regions with active volcanoes. Water
elementals and water mephitis occupy some of the sunless lakes
and seas, while ooze mephits lurk at their fringes. Air elementals
and air mephits are scarcer than the other varieties, but some
can be found near portals to the Elemental Plane of Air.

Extraplanar Creatures: Portals in the Lowerdark open into
almost every plane of existence. Often these portals are not
marked or maintained, but just because the Faerûn side of the
portal has fallen out of use does not mean that these doorways
go unremarked at their destinations. Lone fiends such as
bebiliths or hellcats often find the hunting better on the Material
Plane than in their home realms, and some wind up staying.
Others outsiders sometimes use these portals to raid Toril.
Demons, devils, and other types of outsiders use Lowerdark portals
of varying ages to facilitate their travels.

Psurlons: Wormlike monsters with powerful psionic abilities,
psurlons in the deep Underdark gather into communities known
as clusters. Like beholders and mind flayers, they often dominate
hundreds of useful thralls and set these unfortunate slaves to
whatever tasks the psurlons deem needful at the time.
Tomb Tappers: Also known as thaalud, tomb tappers are huge
constructs forged as weapons of war long ago. Intelligent and
free-willed, these creatures hunger for magic and pursue magic
items (and those who carry them) tirelessly.

Undead: Because undead creatures need no water, food, or air
to survive, many of them find the Lowerdark almost hospitable.
Liches are particularly common here, since they have no need to
prey on the living and find that the Underdark offers blessed
solitude for their sinister studies. Some of the mightiest liches
eventually found small realms or kingdoms here. Such a kingdom
could consist of hundreds or even thousands of mindless
undead laborers and soldiers, led by creatures such as mummies,
vampires, and wraiths.