Dungeons of the Underdark

The Underdark is home to countless monster lairs, sinister cities, forgotten ruins, and planar discontinuities. Regardless of whether the heroes are surface folk boldly venturing into uncharted depths or Underdark natives who are simply looking to defend their homes and discomfit their enemies, the Underdark provides plenty of opportunities for adventure.

Dungeons in the Underdark

A "dungeon" is traditionally located underground, and no part of the Underdark fails to qualify for the term in that respect. For the purpose of adventuring in the Underdark, a dungeon is any locale or extended area that offers the possibility of adventure, danger, and treasure. By this definition, the Underdark contains literally hundreds of dungeons. A few of the most infamous or dangerous are described below.

Fortress of Gurzz'oth: Originally an outpost of the drow city of Sshamath built to defend against the mighty duergar kingdoms located in the Darklands, this fortress and all who lived within it were overcome by a fell necromantic disease. In 1279 DR, the abandoned fortress was claimed by an upperworld wizard named Mamprusi (LE male tiefling Wizard 9) and his cohorts, including two half-orc brothers named Dag and Omba (both CE male half-orc Fighter 7). Mamprusi seeks to open the lowest treasuries of Gurzz'oth, which supposedly contain arcane weapons of war that have never been used in battle. In the meantime, Mamprusi has reinstated magical and mundane security about the fortress.

Irean Bridge: Built over a 1/2-mile wide fissure to connect two sections of an old duergar trade route, the Irean Bridge fell into disuse when molten rock welled up from below. The bridge cracked, and its center span fell into the lava below. Now the remaining sections of the bridge, on either side of the chasm, point toward each other like a pair of arms. Each bridge section was hollowed to form rooms for travelers, barracks for dwarves, storehouses, and prisons. After the molten rock cut off the trade route, the Irean Bridge was slowly forgotten, though lesser creatures of the Underdark may now claim one or both of its remaining spans.

Raval Spire: A mind flayer ruin sealed a thousand years past, Raval Spire is a deep mystery. Supposedly the mind flayers themselves sealed the spire after a secret breeding experiment produced a terrible and voracious result. Unused to such spectacular failure, illithids on the outside sealed in their compatriots along with the spawn that the latter had produced from the blood of demons, drow, illithids, and some unnamed fourth source. The mental screams of the trapped illithids still echo telepathically in the nearby tunnels and caves. No one travels to Raval Spire for fear of the nightmares engendered by mere sight of the towering rock.

Sorath-Nu-Sum: Once a center of kuo-toan politics, Sorath-Nu-Sum was well supplied with pools for recreation and breeding, and it contained many shrines and temples to Blipdoolpoolp, the Sea Mother. One drow-hating kuo-toan faction, led by the cleric Lu, overthrew the ruling council and then massacred every drow trader in the street. Retribution was quick and lethal. Drow mercenaries and terrible aquatic spiders descended on Sorath-Nu-Sum in full force. Now the shrines are empty, and the faithful of Sorath-Nu-Sum sing no more hymns to the Sea Mother. The aquatic spiders and their handlers remain, inhabiting a small corner of the city, but they have orders to kill any returning kuo-toas on sight.

Vaticos: A great library of stolen lore was named Vaticos by its keeper, a derro half-dragon wizard named Barytes. Upon ascending to lichdom, he pulled the whole of his library into a side dimension that would not easily be found from the Material Plane. The only approach to the Vaticos is now a long tunnel in which monstrous guardians and lethal traps keep intruders at bay. Those who reach the Vaticos discover that Barytes is less than happy about would-be browsers in his collection, which houses both mundane and arcane tomes.

Rootstalk: In a cavern of Great Bhacrynden about 1 mile in diameter lurks a colossal fungus that fills every nook and cranny, and its rhizomes and floating spores extend miles farther down connecting side passages. Rootstalk is a single, living, fungal organism, from whose body many passages and chambers have been hollowed out to provide housing for humanoids. At present, humans share this space with mushroom people and other fungal parasites. At the center of Rootstalk's body lie its heart and mind, a jumbled mass of rhizomes where its residents can come to commune with it. Rootstalk communicates with such supplicants via wafts of specially synthesized spores.

Unlike the Araumycos of the Northdark, Rbotstalk seems self-aware and malevolent. All drow and illithid exploration and exploitation parties that have attempted entry have either been turned back or accepted and then consumed. It is possible that Gduar (see below) is allied with Rootstalk.

Citadel of the Fiendish Slayer: This old duergar fortress lies on an island in the lower reaches of the Glimmersea. The citadel is named for the extraplanar parasite that descended upon the gray dwarves in 1312 DR, slaying some and turning others to its service. The outer layers of the fortress are patrolled by duergar brigands, led by a baphitaur warrior-mage called Rumin (CE male baphitaur Fighter 5/Sorcerer 6). His marauders harry both those who sail on the sunless sea and those who travel along nearby tunnels. Rumin knows that his position is secure only so long as he brings suitable sacrifices to the inner chambers of the citadel, where the Fiendish Slayer encysts itself in the flesh of its past victims.

Vault of Conjured Madness: This vault is located in the Middledark, below Chondath. Once a college of sorts, it previously hosted wizards and sorcerers interested in learning and improving the craft of conjuration. But a pod of aboleths located a few miles below the vault eventually grew tired of the occasional slipped or misplaced conjuration appearing in their midst. Though most assume that some conjuration went out of control and destroyed the vault, in fact it was the aboleths who brought the school's cavern down in a great seismic shake. The vault now consists of disconnected ruins linked by half-buried corridors, and it is inhabited only by the restless undead who rose from its former inhabitants. Deep conjuring chambers lie beneath the vault, still haunted by beings summoned almost twenty centuries ago.

Vault of Conjured Madness: This vault is located in the Middledark, below Chondath. Once a college of sorts, it previously hosted wizards and sorcerers interested in learning and improving the craft of conjuration. But a pod of aboleths located a few miles below the vault eventually grew tired of the occasional slipped or misplaced conjuration appearing in their midst. Though most assume that some conjuration went out of control and destroyed the vault, in fact it was the aboleths who brought the school's cavern down in a great seismic shake. The vault now consists of disconnected ruins linked by half-buried corridors, and it is inhabited only by the restless undead who rose from its former inhabitants. Deep conjuring chambers lie beneath the vault, still haunted by beings summoned almost twenty centuries ago.

The Tumulus: In a cavern about 100 hundred miles east of and 10 miles down from Waterdeep lies a mysterious half- buried object called the Tumulus. This solid stone egg measures some 2,000 feet in length, but only one curving tip of it protrudes from the earth. On its surface are inscribed symbols of death in many known and unknown languages, as well as sigils, glyphs, and signs that connote the same. Some of these symbols were charged with lethal magic capable of slaying those who looked upon them, but most such sigils that are not covered in earth have already been discharged. The Tumulus is said to predate ancient Illefarn, and rumor has it that the object is some sort of cemetery. Despite a few half-hearted attempts, however, no entrance into this tomb - if tomb it is - has yet been discovered.

House of Dark Consumption: This sinister area of the lower Deep Wastes is avoided by all sensible creatures, be they living, constructs, or undead. Most unwary individuals and groups that wander into it die there, and those that don't die leave in such a weakened state that they're easy prey for any Underdark denizen that happens upon them. The house was once sacred to an old and bitter aspect of Shar, and a small number of exceedingly powerful undead creatures still stalk its corridors. A tremendous treasure is said to be hidden within, although few have been bold enough to try to seek it out.

The house seems innocuous enough at first. A door leads into an icy corridor of dark, unremarkable stone, and a little wandering makes it apparent to any visitor that the space is extradimensional. Illogically, however, the house is also a dead magic area. Its inner space is mazelike, featuring many corridors, rooms, twists, and turns. The following factors all contribute to the deadliness of this place.

• The walls rearrange themselves periodically (every 1d4 hours), making it extremely easy to get lost.
• Light sources dim, shedding a glow only half as strong as usual. Thus, a bullseye lantern illuminates only a cone 30 feet long and 10 feet wide, while a torch lights no more than a 10-foot radius.
• Unattended items rot away at a rate of 1 point of hardness per hour. When an item reaches 0 hardness, it continues to decompose at the rate of 1 hit point per hour. Thus, any signs or paint left behind to mark a route quickly disappear, and maintaining a base camp from which a group can leave periodically to make forays becomes problematic.
• Attended items rot away at a rate of 1 point of hardness per day. When an item reaches 0 hardness, it continues to decompose at a rate of 1 hit point per day.
• After a full day spent in the House of Dark Consumption, a creature must make a DC 20 Will save or be affected as though with the insanity spell.

Philock: The ruins of this ancient Netherese city lie in the Upperdark, in a region known as the Netherese Caverns. Like Anauria and Blondath, Philock was a successor state of Netheril, founded in the years after the great empire's fall. The city is built in a large rift in the heart of the cavern system. Its buildings stretch through the floor of the canyon and also scale its lower reaches.

Old cave-ins or landslides have buried most of Philock under tons of rock. Intrepid adventurers have tried to excavate parts of the ruins, but with little result. Only a recent drow expedition well-equipped with slave labor has met with any success, but after uncovering an intact stairwell, the slaves doing the excavation fell ill from a deadly inhalation poison (lungrot). This fact has cooled the drow's ardor for continuing the process.

Adventure sites

The following locales expand on the previous section. Each describes a dungeon or adventure site and provides a map and a few keyed encounters for each.

Drowned Multum

In the upper Deep Wastes lie the half-submerged ruins of the city of Multum. The residents of this multicultural trade city were drowned in 1304 by evil outsiders that conjured a deluge of water from the Elemental Plane of Water. Now blind cave fish swim through Multum's wide avenues, and dark shapes float behind the drowned silhouettes of once-mighty buildings. The vaults of dead traders promise riches to any who dare to face the unquiet spirits of the former owners.

The vault that houses Drowned Multum is most readily accessible via a steep vent shaft that leads down into the center of what was once the armory.

Ink Blot (EL 7)

Flowing freely through this chamber and out into the greater vault (unkeyed beyond the armory complex) is a black pudding. At first, this creature appears as nothing more than an inky stain in the already dark water.

If avoided in this chamber, the black pudding pursues intruders into area 2 or 3.

Black Pudding (1): hp 115.

2. Insignia (EL 9)

A successful search of the dank chamber (Search DC 21) brings to light a corroded iron chest beneath the collapsed remains of a wooden table. A second successful DC 34 Search check reveals a vaguely humanoid shape beneath the thick fungus.

The locked chest (Open Lock DC 23) holds six zircon crystals (worth 10 gp each), three leaky (ruined) potion vials, a potion of heroism, a dose of antitoxin, and a gold brooch engraved with the symbol of a sword crossed with an axe (worth 300 gp).

This last item belongs to Thadrack, the mummy fighter lying on the floor. He has lain here so long that his body is now overgrown with fungus. He animates if attacked or if his brooch (see above) is disturbed, fighting the intruders with an unholy glee.

Thadrack: Male mummy fighter 4; CR 9; Medium undead; HD 8d12+3 plus 4d10; hp 77; Init +4; Spd 20 ft.; AC 26, touch 10, flat-footed .26; Base Atk +8; Grp +15; Atk +16 melee (1d6+12, slam); Full Atk +16 melee (1d6+12, slam); SA despair, mummy rot; SQ: Damage reduction 5/- , darkvision 60 ft., undead traits, vulnerability to fire; AL LE; SV Fort +8, Ref +5, Will +9; Str 24, Dex 10, Con -, Int 6, Wis 14, Cha 16.

Skills and Feats. Hide +7, Listen +8, Move Silently +7, Spot +8; Alertness, Improved Initiative, Great Fortitude, Lightning Reflexes, Toughness, Weapon Focus (slam), Weapon Specialization (slam).

Despair (Su): At the mere sight of a Thadrack, the viewer must succeed on a DC 17 Will save or be paralyzed with fear for 1d4 rounds. Whether or not the save is successful, that creature cannot be affected again by Thadrack's despair ability for 24 hours. The save DC is Charisma-based.

Mummy Rot (Su): Supernatural disease slam, Fortitude DC 17, incubation period 1 minute; damage 1d6 Con and 1d6 Cha. The save DC is Charisma-based.

Unlike normal diseases, mummy rot continues until the victim reaches Constitution 0 (and dies) or is cured as described below.

Mummy rot is a powerful curse, not a natural disease. A character attempting to cast any conjuration (healing) spell on a creature afflicted with mummy rot must succeed on DC 20 caster level check, or the spell has no effect on the afflicted character.

To eliminate mummy rot, the curse must first be broken with break enchantment or remove curse (requiring a DC 20 caster level check for either spell), after which a caster level check is no longer necessary to cast healing spells on the victim. The, mummy rot can then be magically cured as any normal disease.

An afflicted creature who dies of mummy rot shrivels away into sand and dust that blow away into nothing at the first wind.

Possessions. +2 chain shirt.

3. Weapon Cache (EL 5)

Both entrances to this waterlogged chamber are secured by heavy, corroded iron doors some 4 inches thick. The doors are locked (Open Lock DC 28) and trapped.

Phantasmal Killer Trap: CR 5 magic device; proximity trigger (10 feet in front of each door); automatic reset; spell effect (phantasmal killer, 7th-level wizard, DC 16 Will save for disbelief and DC 16 Fortitude save partial); Search DC 29; Disable Device DC 29.

Room 3 is flooded to a depth of 3 feet.

All the items that are easily visible are ruined. A DC 28 Search check made while sifting through the detritus below the water level reveals a metal cabinet, still closed and locked (Open Lock DC 30). Inside are 2 +2 longswords, 1 +2 crossbow, and a +3 flaming burst greatsword.

4. The Sentinel (EL 14)

Before the city's inhabitants were drowned, the guardian of this armor kept watch over the approach to the weapon cache. Now, those entering Drowned Multum from the outside must pass through the armory before encountering its guardian. Still, anyone seeking to enter the much larger vault of ruins that is Drowned Multum must pass by this doughty armored sentinel who cares not about the passage of time.

Advanced Clay Golem: CR 14; Large construct; HD 15d10+30; hp 113; Init -1; Spd 20 ft; AC 31, touch 8, flat-footed 31; Base Atk: +11; Grp +22; Atk +18 melee (2d10+8 plus cursed wound, slam); Full Atk +18 melee (2d10+8 plus cursed wound, 2 slams); Space/Reach 10 ft./10 ft.; SA berserk, cursed wound; SQ: construct traits, damage reduction 10/adamantine and bludgeoning, darkvision 60 ft., haste, immunity to magic, low-light vision; AL N; SV Fort +5, Ref +4, Will +5; Str 26, Dex 9, Con -, Int -, Wis 11, Cha 1.

Skills and Feats: none.

Berserk (Ex): When a clay golem enters combat, there is a cumulative 1% chance each round that its elemental spirit breaks free and goes berserk. The uncontrolled golem goes on a rampage, attacking the nearest living creature or smashing some object smaller than itself if no creature is within reach, then moving on to spread more destruction. Once a clay golem goes berserk, no known method can reestablish control.

Cursed Wound (Ex): The damage a clay golem deals doesn't heal naturally and resists healing spells. A character attempting to cast a conjuration (healing) spell on a creature damaged by a clay golem must succeed on a DC 26 caster level check, or the spell has no effect on the injured character.

Construct Traits: A clay golem has immunity to poison, sleep effects, paralysis, stunning, disease, death effects, necromancy effects, mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects), and any effect that requires a Fortitude save unless it also works on objects or is harmless. It is not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, or energy drain. It cannot heal damage, but can be repaired.

Haste (Su): After it has engaged in at least 1 round of combat, a clay golem can haste itself once per day as a free action. The effect lasts 3 rounds and is otherwise the same as the spell.

Immunity to Magic (Ex): A clay golem is immune to any spell or spell-like ability that allows spell resistance. In addition, certain spells and effects function differently against it, as noted below. A move earth spell drives the clay golem back 120 feet and deals 3d12 points of damage to it. A disintegrate spell slows the clay golem (as the slow spell) for 1d6 rounds and deals 1d12 points of damage.

An earthquake spell cast directly at a clay golem stops it from moving on its next turn and deals 5d10 points of damage. The golem gets no saving throw against any of these effects. Any magical attack against a clay golem that deals acid damage heals 1 point of damage for every 3 points of damage it would otherwise deal. If the amount of healing would cause the golem to exceed its full normal hit points, it gains any excess as temporary hit points. A clay golem gets no saving throw against magical attacks that deal acid damage.

Possessions: +1 full plate armor.

Greater Multum

Beyond the armory and its guardians lies a waterscape from which the damp, crumbling ruins of greater Multum jut upward haphazardly.

Gduar's Garden

In the upper reaches of the Darklands, below the Chondalwood, lie vast tracts of wild caves in which the fungus growth has completely choked off all animal life. Here, life of a slow, vegetable sort reigns supreme. The beautiful mushrooms in these areas are part of the cycle of life, subsisting on the decaying forms of animals and plants. Sometimes, however, fungi don't wait for their meals to die - and in Gduar's Garden, this is always the case.

Because fungi digest food outside their bodies by releasing enzymes into the surrounding environment, the inner core of the garden slowly kills most non-fungal creatures that enter it, as if it were one vast, slow-digesting stomach. When a particularly large meal is available, the garden releases spores from its thousands of fruiting bodies (mushroom-like growths) into the air. Gduar's breath weapon (see below) then carries spores farther into the Underdark, continuing the colonization that Gduar sees as its destiny.

1. Gelatinous Floor (EL 3)

A layer of mundane ooze coats the floor and some of the walls of this cavern. Sprouting up through this slimy layer are small, bright yellow mounds. Though they are as wide and thick as fingers, these are just simple fruiting bodies. More insidiously, the mundane ooze covering the floor hides a gelatinous cube that is currently residing in a recess in the floor (Search DC 27). The creature is generally kept complacent and unmoving through steady feeding, but any creature that walks over the area marked G on the map is automatically engulfed. The cube currently contains a +2 mace, a set of +1 banded mail, and 360 gp.

Gelatinous Cube (1): hp 58.

2. Garden Guardian (EL 12)

Like room 1, this chamber is host to a variety of fungal populations, which grow even thicker here than in the previous chamber

No hidden threat lurks here; the room's only guardian is an advanced shambling mound infused with violet fungus, granting it the poison ability of the violet fungus. It stands ready to deflect any creatures not under Gduar's protection who would enter area 3.

Wound up in the mass of the creature's flesh are several trophies of its past victories: a wand of knock (16 charges), a ring of climbing, and 436 gp.

Advanced Violet Fungus-Infused Shambling Mound: CR 12; Huge plant; HD 24d8+120; hp 228; Init +3; Spd 20 ft.; AC 22, touch 7, flat-footed 22; Base Atk +18; Grp +3Y; Atk +26 melee (3d8+9 plus poison, slam); Full Atk +26 melee (3d8+9 plus poison, 2 slams); Space/Reach 15 ft./15 ft.; SA constrict 2d8+13, improved grab, poison; SQ: Darkvision 60 ft., immunity to electricity, low-light vision, plant traits, resistance to fire 10; AL N; SV Fort +19, Ref +9, Will +10; Str 29, Dex 8, Con 21, Int 7, Wis 10, Cha 9.

Skills and Feats. Hide +15, Listen +18, Move Silently +18; Awesome Blow, Cleave, Improved Bull Rush, Improved Initiative, Improved Natural Attack, Iron Will, Lightning Reflexes, Power Attack, Weapon Focus (slam).

Constrict (Ex): The shambling mound deals 2d8+13 points of damage with a successful grapple check.

Improved arab (Ex): To use this ability, the shambling mound must hit with both slam attacks. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can constrict.

Poison (Ex): Injury, Fortitude DC 27, initial and secondary damage 1d4 Str and 1d4 Con. The save DC is Constitution-based.

Immunity to Electricity (Ex): The shambling mound takes no damage from electricity. Instead, any electricity attack (such as shocking grasp or lightning bolt) used against the creature grants it 1d4 points of Constitution. It loses these points at the rate of 1 per hour.

Plant Traits: The shambling mound is immune to poison, sleep effects, paralysis, stunning, polymorphing, and mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects). It is not subject to critical hits. Lowlight vision.

3. Garden of Digestion (EL 9)

This immense cavern boasts phosphorescent fungus on every surface. So crowded are the fungi here that they have formed a symbiotic mass that communally digests prey.

These rare and beautiful fungi are all tended by Gduar (see area 4), and together they form a whole greater than their parts. The smelly, glowing mist that pervades this chamber is actually a digestive haze. Each round, every creature in the chamber takes 1d4 points of damage from the settling digestive spores (no saving throw). Elementals and plants are immune to this effect. Every 10 rounds, a breeze blows from the northeast toward the southwest, sending a puff of the glowing mist down the hallway toward area 2.

A few ambulatory fungoids also inhabit this area. At the periphery of the room hide two normal shambling mounds and a tendriculos (Spot DC 26). They are the hunter-gatherers for this fungal colony. Once every 24 hours, Gduar sends them out with instructions to forage for prey to bring back into this chamber, so that the digestive haze can feed the other fungi. Since prey has been good enough to come to the garden today, these creatures do not move from their positions unless the intruders begin a fight with Gduar in area 4.

Shambling Mounds (2): 60 hp each.

Tendriculos (1): hp 94.

4. Gduar's Lair (EL 14)

This chamber is actually the outermost layer of a Class 3 node.

This creature is Gduar. It resembles a treant whose body is wholly fungal instead of woody. Gdaur's own self-directed unique evolution allows it to slowly grow those traits it most treasures - a translucent, gelatinous body mass overgrown and partly occluded here and there with ropy growths of mold. Like a gelatinous cube, his body is fully capable of digesting most anything trapped within it.

The digestive haze of the adjoining chamber also persists here, dealing 1d4 hit points of damage per round of exposure to each creature (see area 3).

Gduar keeps a vault of treasure, coated in a black ooze, buried in the chamber (Search DC 29). In addition to "mundane" magic items it has collected from its many victims (2d4 random +1 weapons, 2d4 random +1 armors, 2d4 random minor magical items, and 3,342 gp) are a drow mission blade and the Third Imaskarcana. Many have died seeking that ancient relic here.

Gduar: CR 14; Huge aberration; HD 16d10+112; hp 200; Init +3; Spd 20 ft.; AC 25 (touch 7, flat-footed 25); Base +12; Grp +29; Atk +20 melee (3d6+9 plus 1d8 acid and paralysis, slam); Full Atk +20 melee (3d6+9 plus 1d8 acid and paralysis, 2 slams); Space/Reach 15 ft./15 ft.; SA acid, animate fungus, breath weapon (spores), double damage against objects, engulf, improved grab, paralysis; SQ: blindsight, resilient, immunity to electricity, fire vulnerability, damage reduction 10/slashing, plant traits; AL N; SV Fort +12, Ref +4, Will +13; Str 29, Dex 8, Con 24, Int 12, Wis 16, Cha 12.

Skills and Feats. Diplomacy +3, Hide -9*, Intimidate +11, Knowledge (nature) +11, Listen +14, Sense Motive +12, Spot +14, Survival +12; Alertness, Cleave, Improved Initiative, Improved Natural Weapon% Power Attack, Weapon Focus (slam).

Acid (Ex): Gduar's acid does not harm metal or stone. The acid deals 1d8 damage per round to those engulfed.

Animate Fungus (Ex): Gduar can animate fungus within 180 feet at will, controlling up to two fungal masses at a time. It takes 1 full round for a normal mass of fungus to animate. Thereafter it move's and fights as a shambling mound in all respects. Animated fungi lose their ability to move if Gduar is incapacitated or moves out of range. The ability is otherwise similar to liveoak (caster level 12th).

Breath Weapon (Su): Spores, 60-foot line, damage 8d10, Reflex DC 25 half. Gduar is immune to its own breath weapon. The save DC is Constitution-based.

Double Damage Against Objects (Ex): When Gduar makes a full attack against an object or structure it deals double damage.

Engulf (Ex): On a successful grapple check in the round subsequent to being grabbed, Gduar can engulf foes it has grabbed into its gelatinous body. Engulfed creatures are subject to Gduar's paralysis and acid, and are considered to be grappled and trapped within its body.

Improved Grab (Ex): To use this ability, Gduar must hit with its slam attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it can engulf.

Paralysis (Ex): Gduar's gelatinous interior secretes an anesthetizing slime. A target hit by Gduar's melee attack or who is engulfed must make a DC 25 Fortitude save or be paralyzed for 3d6 rounds. Gduar can automatically engulf a paralyzed opponent. The save DC is Constitution based.

Blindsight (Ex): The fungus substance of Gduar's body acts as a primitive sensory organ that can ascertain prey within 60 feet.

Resilient (Ex): Gduar has a less defined shape than normal creatures. As a result, Gduar can not be flanked.

Plant Traits: Even though it is now an aberration, Gdimar still has its plant traits. It is immune to poison, sleep effects, paralysis, stunning, polymorphing, and mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects). It is not subject to critical hits. Low-light vision.

Skills: *Gduar has a +16 racial bonus on Hide checks made in fungal areas.

Shape of Water

The Lowerdark is rife with hidden aquifers and umbral oceans where conditions are inimical to all, where strange creatures unknown to other parts of the Underdark wander, amid where the aboleths have their enclaves. One of the most spectacular of these areas is the aboleth fortress known as the Shape of Water, which lies in a cavern outpost of the Glimmersea.

The Shape of Water is the first of several outposts charged with defending the perimeter of a larger aboleth territory. Those protected by the Shape of Water have faith that it will not fail in its duty to the greater nation beyond.

Umbra, the aboleth who captains the Shape of Water, is the latest in an unbroken familial line of aboleths that has been stationed in the Shape of Water. Because an aboleth inherits its parent's knowledge at birth and assimilates the memories of all it consumes, Umbra is wise to any and all tricks that would-be intruders have used throughout the centuries to attempt to circumvent the fortress.

In Umbra's service in the lake below are several slaves of various kinds. As a sign of time slaves' service to it, they have translucent skin but are otherwise like other creatures of their kinds.

1. Doorstep (EL 10)

A pool of water fills this 60-foot-diameter cavern to a depth of 30 feet at its deepest. A pair of skums (misbegotten humanoids created by aboleths as a slave race) inhabit the west edge of the pool, keeping watch on the tunnel approach. They are trained to speak Undercommon as well as Aquan. They warn any creature that deigns to speak to them that beyond this chamber lies a region forbidden to all races, and that the PCs must turn back or be destroyed.

Besides the two skums, the water conceals five scrags. These creatures and the skums attack any characters who press toward the door to area 2.

Skums (2): hp 11.

Scrags (5): hp 63.

2. Antepool (EL 8 and 13)

The west entrance to this roughly 80-foot-diameter cavern is sealed by a stone door, relief-carved with what appear to be multiple snakes or tendrils. The door is locked (Open Lock DC 28) and trapped.

Whirling Poison Blades Trap: CR 8; mechanical; proximity trigger; automatic reset; hidden lock bypass (Search DC 25, Open Lock DC 30); Atk +10 melee (1d4+4/19 - 20 dagger plus poison), poison (purple worm poison, Fortitude DC 24 resists, 1d6 Str/1d6 Str); multiple targets (attacks all targets in 20-ft. area west of door); Search DC 20; Disable Device DC 20.

Underneath the placid water lurk more skums as well as the real threat to those who would attempt entry - a beholder. When the beholder attacks, the skums attempt to hide and observe.

Skums (2): hp 11.

Beholder (1): 60 hp.

3. Vault of Water (EL 15)

The west entrance to this immense cavern is sealed by stone doors, relief-carved with what appear to be multiple snakes or tendrils. The door is locked (Open Lock DC 30) and trapped.

Acid Fog Trap: CR 7; mechanical; proximity trigger; automatic reset; hidden lock bypass (Search DC 25, Open Lock DC 30); spell effect (acid fog, 11th-level wizard, 2d6 acid/round for 11 rounds); Search DC 31; Disable Device DC 31.

This massive chamber is lit by a blue phosphorescent fungus that coats all its walls. This vault houses a deep lake of water, with only a single 10-foot-diameter island visible in the middle. The most astounding feature of the room, however, is the 65-foot-diameter suspended globe of water that floats serenely in the air. Whizzing around the main globe at a rate of one revolution pe six seconds is a smaller, 20-foot-diameter globe of water. Within the larger globe swims a 20-foot-long, fishlike monstrosity.

The creature within the globe is Umbra. Its troops in this area include four cloakers that nest in the upper reaches, a couatl that nests on the island at the center of the lake, and three gibbering mouthers. These thralls have translucent flesh and are ready to defend the aboleth from intruders whenever it gives them the sign.

Umbra can direct the globe, which is actually the Shape of Water, as a free action. The Shape of Water moves at a fly speed of 50. Each round, the rapidly whizzing minor globe orbiting the main sphere can attack any one creature within 40 feet of the main globe that Umbra designates with a slam (+33 melee, 4d10+14 plus slime). See the aboleth for details on the slime attack. The main globe is AC 23, hardness 2, and 500 hp. If it is brought to 0 hit points, both the globe and its orbiting sphere collapse. While within the Shape of Water, Umbra can attack using its psionics or its enslave ability from a distance.

Floating at the center of the Shape of Water is a hoard of treasure taken from those who have previously attempted passage. The treasure includes 4,325 gp, 1d3+2 weapons, 1d3+2 armors, and 1d3 medium-potency magic items.

Cloakers (4): hp 45.

Couatl (1): hp 58.

Gibbering Mouthers (3): hp 22.

Umbra-Aboleth (1): hp 76.

4. Inlet

This water-filled tunnel is not visible from above the surface of the lake in area 3. It leads through greater and greater concentrations of aboleth defenses, until it finally ends in a large aboleth enclave whose existence is so secret that its name (Xxiphu) is revealed only in the rarest texts.

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The Underdark