Waterdeep: Dungeon of the Mad Mage

Huge Gray Ooze

The characters encounter six Ghaunadaur-worshiping duergar who were transformed by Halaster's magic into a single gray ooze with a challenge rating of 8 (3,900 XP) and these changes:

• The ooze is Huge, with 152 (16d12 + 48) hit points and a Strength score of 18.
• As an action, it can make two attacks with its pseudopods (+7 to hit). On a hit, a pseudopod deals 21 (6d6) acid damage, or 42 (12d6) acid damage while the ooze is enlarged.
• The ooze has the Enlarge and Invisibility traits below.

Intelligent Black Puddings

The characters encounter two Ghaunadaur-worshiping drow who were transformed by Halaster's magic into black puddings, with these changes:

• The black puddings understand Elvish and Undercommon, but can't speak.
• Each pudding has an Intelligence of 14 and the following Innate Spellcasting trait:

Space Orogs

The characters encounter 1d4 + 1 orogs hunting for easy prey. These orogs were raised in deep caverns on H'catha, a wheel-shaped planet ruled by beholders and the farthest world from Toril's sun. The orogs wear bucket helms resembling bulbous mind flayer heads, with large, glass-covered eye holes and tentacle-like breathing tubes.

In addition to its armor and weapons, each orog carries a tangler grenade. The orogs use these grenades to restrain foes before charging into melee.

1a. Shipwreck

This 50-foot-high cavern contains the wreck of a cog (a 54-foot-long cargo vessel with a single mast). The wreck's features are as follows:

Characters who search the wreck discover its name carved over the barnacle-encrusted rudder: the Blue Opal. A character who learns the ship's name and succeeds on a DC 20 Intelligence (History) check recalls that the Blue Opal sank in Waterdeep's harbor a few years ago under mysterious circumstances, and that the crew was rescued by merfolk who live in the harbor. Armed with this knowledge, a character can examine the hull for signs of foul play and, with a successful DC 15 Intelligence (Investigation) check, discover a square, smooth-cut hole in the aft section below what would have been the water line. A successful DC 16 Intelligence (Arcana) check confirms that a disintegrate spell made the square hole, but there's no way to know who cast the spell or why the ship was sunk.

If more than one character enters the aft section at the same time, the partial hull shifts under the added weight, topples to one side, and collapses in on itself with a thunderous racket. Any creature inside the aft section when it collapses must make a DC 15 Dexterity saving throw, taking 22 (4d10) bludgeoning damage from falling debris on a failed save, or half as much damage on a successful one. The watery curtains in x prevent the sound of the collapse from reaching x.

1b. Curtains of Water

This passage has a 20-foot-high, arched ceiling and contains three 1-foot-thick, magic curtains of translucent, shimmering green seawater. Each watery curtain stretches from floor to ceiling and wall to wall. Sound passing through a curtain is greatly reduced; only creatures within 5 feet of it can hear anything from the other side.

Any object thrown or shot through a watery curtain has a cost of 60 feet immediately applied to its distance traveled. If this added distance changes a ranged weapon attack from normal to long range, the attack roll is made with disadvantage. An object that enters the curtain and can travel no farther falls to the floor inside the curtain.

Spell effects that would not reasonably pass through the watery curtain are stopped by the barrier as though it were a solid wall. For example, a magic missile spell could pass through the curtain to hit creatures on the far side of it, but the explosion from a fireball spell would not get through the barrier.

A creature that passes through a watery curtain gets drenched but suffers no other ill effects. In addition, lit torches and other open flames of a nonmagical nature are doused as they pass through the water. Any creature that takes damage from water, such as a fire elemental, takes 11 (2d10) cold damage when it starts its turn in a watery curtain or enters it for the first time on a turn.

If a watery curtain takes 50 cold damage or more from a single source, it becomes a 1-foot-thick wall of ice (as if created by a wall of ice spell) for 10 minutes before reverting to its original form. A watery curtain targeted by a successful dispel magic spell (DC 17) is destroyed for good.

1c. Ichthyglug's Cavern

The marid, Ichthyglug, is swimming in his pool when the characters first arrive. He greets them with a song (see the "x" sidebar). As he sings, Ichthyglug uses his magic to cause fountains of water to erupt from the pool as quippers leap out of the water around him. Ichthyglug is neither good nor evil, but always unpredictable. His attitude toward the characters reflects their attitude toward him.

After concluding his song, Ichthyglug floats up to characters who seem receptive and gives them the opportunity to flatter his singing. After these pleasantries, he offers the characters a quest: destroy the lich Ezzat on level 20 and give the lich's phylactery to Ichthyglug. The marid promises fabulous treasure in exchange, even going so far as to mention that he is forced by Halaster's magic to make good on this promise (see "Treasure" below).

If the characters complete Ichthyglug's quest and give Ezzat's phylactery to the marid, the pool in this cavern turns into a vortex that draws Ichthyglug, the water, the quippers, and the lich's phylactery back to the Elemental Plane of Water. The characters find Ichthyglug's promised reward at the bottom of the drained pool. Characters who complete Ichthyglug's quest should receive XP as if they had defeated the marid and the swarms of quippers in combat.

If the characters destroy Ezzat but give the lich's phylactery to Jarûk the dao in x, Ichthyglug knows this. Furious, he attacks the characters the next time he sees them.

Ichthyglug can't leave his cave without Ezzat's phylactery. If the marid dies here, his body disintegrates into a burst of water and foam, only to re-form 24 hours later. (The characters don't receive XP for killing Ichthyglug more than once.)

The marid commands the quippers to attack anyone who dares to enter his pool. The swarms pose no danger to creatures on land.

Treasure

Rukha the orog has a sending stone tucked in one of her gauntlets. Rukha's mate, the former cook of the Scavenger, had the matching stone but lost it (see x).

3a. The Great Ooze March

The river of ooze flows north through this 15-foot-high cave (see "x"). When the characters first arrive, the ooze rises and takes the form of a conga line of modrons stretching as far as the characters can see. The modrons march against the sluggish flow and make little progress. After 1 minute, they sink back into the ooze. The ooze modrons aren't creatures or spell effects, and they can't be harmed or dispelled.

3b. Ooze Halaster

An artery of ooze flows down this tunnel and pools in a slight depression in the rocky floor. The first time anyone comes within 10 feet of the pool, the ooze rises up, takes the form of Halaster Blackcloak, and flails its arms in a way that suggests it might be trying to cast a spell. After 1 minute, the effigy of Halaster loses its form and becomes a pool of ooze once more. The ooze isn't a creature and can't be harmed, nor is it a magical effect that can be dispelled.

Orb of Ooze

The orb is immobile, though it can be moved with a telekinesis spell or similar magic. Casting a disintegrate spell on the orb destroys it and stops the flow of ooze into the cavern. Other spells have no effect on the orb.

Creatures and objects can pass through the orb, which is made of the same ooze found throughout this level of the dungeon. Any creature that enters the orb is restrained by it. A creature restrained by the orb can use an action to make a DC 15 Strength (Athletics) or Dexterity (Acrobatics) check, freeing itself on a success. Another creature outside the orb can use an action to attempt the check if its within reach of the restrained creature; on a successful check, the creature is freed from the orb.

5a. Pudding Pit

This naturally formed pit is 20 feet across and 20 feet deep. At the bottom of the pit are three intelligent black puddings (see "x") that used to be drow worshipers of Ghaunadaur. When they detect prey nearby, the puddings climb the sides of the pit and use faerie fire spells to outline their intended targets before attacking with their pseudopods. The puddings cast Melf's acid arrow spells at prey beyond their reach.

5b. Standing Gate to Level 12

At the north end of this 20-foot-high cave are two 15-foot-tall standing stones hewn from black basalt. Carved into the lintel spanning them is a large, blood-red X. The standing stones form one of Halaster's magic gates (see "x").

When a creature comes within 5 feet of the gate, rivulets of blood begin to seep from the rocky pores of the standing stones. The rules of this gate are as follows:

• The gate opens for 1 minute if a creature marked with a bloody X stands within 5 feet of it.
• Characters must be 12th level or higher to pass through this gate (see "x"). The first creature to pass through the gate triggers an elder rune (see "x").
• A creature that passes through the gate appears in x, in the closest unoccupied space next to the identical gate located there.

Beholder Memories

Nalfeshnees

The sleeping demons can't be targeted by spells or attacks while trapped inside the crystal menhirs. They remain asleep until awakened (see "Standing Gate" below). An awakened nalfeshnee teleports out of its menhir and attacks, then returns to slumber in its menhir when there are no more enemies in sight.

Standing Gate

The crystal menhirs are indestructible and form one of Halaster's magic gates (see "x"). Striking either menhir with a hard object or targeting it with a shatter spell deals no damage but causes the standing stone to ring loudly, awakening the demon inside. Nothing else causes these demons to awaken. While outside its menhir, a nalfeshnee can be magically compelled to divulge the command word that activates the gate. A legend lore spell or similar magic also reveals the command word. The current word is "Kelserath," but Halaster changes it every few days.

The rules of this gate are as follows:

• The gate opens for 1 minute if a creature speaks the proper command word within 10 feet of it.
• Characters must be 16th level or higher to pass through this gate (see "x"). The first creature to pass through the gate triggers an elder rune (see "x").
• A creature that passes through the gate appears in x, in the closest unoccupied space next to the identical gate located there.

Treasure

The dead beholder has a gold tongue stud set with a peridot (750 gp).

Treasure

A gargoyle that dies but isn't disintegrated outright falls to stony pieces, revealing a fist-sized, transparent red garnet (500 gp) where its heart used to be.

11a. Fortune Favors the Boulders

If the characters attack Jarûk in x, the galeb duhr attack the characters when they return to this cave. Otherwise, the creatures remain motionless and pose no danger. If provoked into attacking, the galeb duhr animate boulders. The galeb duhr and their boulders can pursue prey beyond the confines of this cavern.

11b. Jarûk's Cavern

The dao, Jarûk, rises out of the sand when the characters first arrive. He greets them with a song (see the "Jarûk's Song" sidebar). As he sings, the veiled medusas emerge from their alcove and begin to dance around him as the sand swirls and forms little dust devils. Jarûk is evil and cruel, but his current predicament motivates him to be a civil host.

Once his song has ended, Jarûk offers the characters a quest: destroy the lich Ezzat on level 20 and bring him the lich's phylactery. The dao promises treasure in exchange and is forced by Halaster's magic to make good on this promise (see "Treasure" below). If the characters complete Jarûk's quest and give Ezzat's phylactery to the dao, the sandy floor turns into a giant vortex that draws Jarûk, the medusas, the sand, and the lich's phylactery back to the Elemental Plane of Earth. The characters find Jarûk's promised reward on the floor of the emptied cave. Characters who complete Jarûk's quest should receive XP as if they had defeated the dao and the medusas in combat.

If the characters destroy Ezzat but give the lich's phylactery to Ichthyglug the marid in x, Jarûk knows this and attacks the characters the next time he sees them.

Jarûk can't leave his cave without Ezzat's phylactery. If the dao dies here, his body disintegrates into crystalline powder, only to re-form 24 hours later. (The characters don't receive XP for killing Jarûk more than once.)

The medusas defend the dao to the best of their ability. Jarûk is immune to their Petrifying Gaze.

Treasure

The altar's hidden cavity contains 2,000 cp.

13a. Upper Deck

Ballistae. Three ballistae are mounted on the forward deck, and a fourth on the aft deck. Four gray slaadi shapechanged into orogs operate the ballistae, one per weapon.

Hatch. Not visible from the floor of the cavern is an open hatch with a ladder that descends to x.

A ballista is a Large object with AC 15, 50 hit points, and immunity to poison and psychic damage. Before it can be fired, a ballista must be loaded and aimed. (The ballistae are loaded when the characters first arrive.) It takes one action to load the weapon, one action to aim it, and one action to fire it (+6 to hit, range 120/480 ft., one target). On a hit, a ballista bolt deals 16 (3d10) piercing damage.

Each ballista comes with ten bolts stored in a rack built into the weapon's stand. A swivel base gives each ballista a firing arc of 180 degrees.

The slaadi have been trained to load, aim, and fire the ballistae. They defend the deck against all boarders, relying on their darkvision to keep watch.

13b. Cargo Hold

The dead orog on the ladder hangs by one of its spiked boots. A character can use an action to dislodge the dangling fellow. Examination of all three orogs reveals that their skulls were cracked open and their brains sucked out—the hallmark of a mind flayer attack. The orog in the apron lies outside the door to x.

13c. Galley and Mess Hall

This room contains a dining table, six stools, and a small iron stove. Cupboards built into the walls have been thrown open, their contents (utensils and dishware) scattered across the floor.

Casting a detect magic spell in this cabin reveals an aura of evocation magic emanating from inside the wall that separates this room from x.

13d. Captain's Stateroom

N'ghathrod straps captives to this chair before devouring their brains. A creature shackled to the chair can use an action to try to escape, doing so with a successful DC 20 Strength (Athletics) or Dexterity (Acrobatics) check.

13e. Starboard Crew Cabin

This cabin contains two sets of bunks stacked three tiers high.

13f. Port Crew Quarters

This cabin is furnished like x and also contains a dead orog lying face down on the floor. Examination of the corpse reveals that the orog's skull was cracked open and its brain sucked out. Lying at the orog's feet is a greataxe.

13g. Bridge

The door to the bridge stands slightly ajar. N'ghathrod, the mind flayer captain, is here (see the "x" sidebar). The features of the bridge are as follows:

Characters who examine the grooves and succeed on an Intelligence (Investigation) check can ascertain that they're designed to secure a heavy chair or chair-shaped object to the floor. The grooves conform to the footprint of the ship's spelljamming helm, which can be found on level 23.

The chart on the ceiling has the sun at its center, with elongated rings showing the paths of the eight planets that orbit it: rocky Anadia; Coliar the gas giant; Toril and the small asteroid cluster orbiting it called the Tears of Selûne; the water worlds Karpri and Chandos; the noxious ringed planet Glyth; the asteroid cluster of Garden, which is held together by an enormous plant; and the wheel-shaped H'catha. Beyond the planets are the constellations of Realmspace, all visible in the night skies of Toril at various times of the year.

13h. Oh Captain, My Captain!

The floor here is covered with shattered glass and brine, the remains of jars that once held pickled humanoid brains. The curved walls bear empty shelves where Captain N'ghathrod stored its emergency food reserves. The mind flayer was forced to eat the pickled brains after its crew fled and now hungers for fresh food.