The Metamorphic Cistern (and Pb dungeon rules)

After the Phrydian empire fell to the Conquest, its citizens began to transmogrify into Birdfolk. In this hidden laboratory, Dr. Xyn tried and failed to find a way to reverse that transmogrification. WARNING: I designed this dungeon so that almost every room has the potential to cause permanent bodily change to the heroes, so if that's not your jam, this dungeon won't be your vibe.

AVIOMORPHOSIS. The transformation into Birdfolk has three stages. In stage 1, feathers grow intermittently across the body, though a painful plucking can mitigate the effect. In stage 2, feathers irreversibly cover the entire body, and a beak structure begins to form. In stage 3, the transformation is total, and the new Birdfolk loses all memory of their past life.

PHRYDIAN CAIRN. A vertical shaft is hidden by the ritualistically-stacked ruins of an old Phrydian academy building.

• The shaft opens right above the pool in the middle of the CISTERN CHAMBER.
• Three Birdfolk (Hangnail, Need-To-Piss) patrol the area; their leader (Stubbed-Toe) carries a whip that animates when covered in blood.

CISTERN CHAMBER.* A deep pool sits in the middle of this domed, pillared atrium, lined with doors.

• Every round spent in the contaminated water, roll TNCT against aviomorphosis. At the bottom, resting atop a wad of sloughed-off feathers, is the key to the RESCALE CHAMBER.
• Two of the six doors are locked, the rest are variously open and stuck: the GRAFTING LATTICE (key on Deuce’s belt) and the RESCALE CHAMBER (key at the bottom of the pool). Each door is labeled in Phrydian.

MOSAIC PANOPTICON. Three humanoid silhouettes swim within this room’s tiled walls. A quivering lump with too many wings and eyes sits in the room’s center.

• The biblically-accurate loaf (Please Don’t Kill Me) comes from the second dimension, unwittingly serving as a living gateway between planes and turning the walls into connection points between the 2 and 3d. If anyone gets close to it, it lets out a concussive scream.
• The tile silhouettes (Airita, Zettul, Thomicron) are Phrydian prisoners. They try to pull anyone in reach into the 2d, out of the hopes that the allies of someone pulled in knows how to reverse the process.

MIRROR HALL. Against the walls are three mirrors.

• One mirror reflects what happened 10 minutes in the past.
• One mirror contains inverted versions of the heroes, trying to convince them to break the glass so they can escape and replace their counterparts.
• One mirror is normal, but on its back is carved a map of the surrounding area, complete with other Phrydian now-ruins not marked elsewhere.

INVERSION MATRIX.* Two glass tubes, covered in runes, are connected to a lever in the middle of the room. A small monkey sits, chewing on the rotting corpse of a Birdfolk.

• Pulling the lever swaps souls between the glass tubes.
• The monkey (Jericho) has the Birdfolk’s soul; she killed her monkey-souled body for food after she was subject to the first successful use of the matrix.

SERVITOR STATUARY. Three lifelike statues of human-hawk hybrids stand, one of which holds an amethyst orb.

• Anyone that nakedly touches the Orb of Calcification turns to marble. If more than 3 creatures would be simultaneously petrified, the first to be petrified reverts.
• Each statue is a petrified Hawkfolk, one of Dr. Xyn’s old servants (Prime, Deuce, Bronze). They each have one vial of aviomorphosis suppressant that works for [WEIRD] hours, the last of their kind. Deuce holds the GRAFTING LATTICE key.

GRAFTING LATTICE. A wicked-looking steel chair, complete with restraints, is haphazardly strapped to an empty cage.

• If you put an animal in the cage and sit in the chair, there’s an agonizing flash; you beneficially mutate into a hybrid, but the animal is killed.

RESCALE CHAMBER.* A runic circle on the middle of the floor mirrors a dial on the wall. Resized bric-a-brac litters the available floor.

• Turning the dial proportionally changes the size of whatever’s put in the circle.
• Among the resized paraphernalia is a dollhouse-sized castle and a ribcage-sized cut ruby.

*If table rhythm dictates, roll for random encounter as part of room stocking, ignoring a result of 1.

RANDOM ENCOUNTERS.

1 A SOUR, OLD WORLD WIND BLOWS. Roll TNCT against aviomorphosis.

2 BIRDFOLK PATROL. See the PHRYDIAN CAIRN.

3 VINCENZO HAUPASKETTI. This chauvinistic Saccharinian falsely fancies himself a hypercompotent, famous tomb robber.

4 ESCAPED MOSAIC. Having found the INVERSION MATRIX, this prisoner (Veducius) is trying to get back to the MOSAIC PANOPTICON in order to share his discovery.

5 FAILED EXPERIMENT. What even is that thing? Hungry, that’s for damn sure.

6 WHAT REMAINS OF DR. XYN. Once, Dr. Xyn was a genius arcanoengineer. Now, the madness of failure to stop the aviomorphosis of his civilization and repeated exposure to mutagens have turned him into a lumbering, weeping amalgam of animal parts.

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The Cistern is my excuse to post what really matters, which is these two glorified bullets that are just a rephrasing and cleaning-up of my thoughts in the Reactive Random Encounters post linked above:

UNDERTAKING. Anything that takes more than a couple of minutes is an UNDERTAKING. In the middle of an UNDERTAKING, roll for a RANDOM ENCOUNTER (a d12 if the UNDERTAKING will take less than an hour, otherwise a d6, guaranteeing interruption). At the end of an UNDERTAKING, disposable light (like torches) extinguish, and replenishing light (like lanterns) check USAGE.

LICKING WOUNDS. Spend a half hour's UNDERTAKING performing basic first aid to replenish [WEIRD] SOMA. (This is your short rest analogue; a good night's sleep in a warm bed replenishes all SOMA.)

Thanks for reading, and happy gaming.