The Ice and Ruin Dungeon Maker

This is built on a modified DnDw/PornStars Instadungeon chassis. It works like this:

1. Roll the dungeon's purpose (d20).
2. Roll one or more factions to inhabit the dungeon (d20).
3. Drop dice (d4-d10) onto paper for the rooms. Draw the map.
4. Drop more dice (d4-d20) onto the map to give rooms complications. This is a stacking table, so lower results will appear more often. Roll oddities (d100).

Skip the steps you don't need for your purpose, or just use one if you need a little sprinkle of something on another project. My aesthetic goals were creepy, sad, darkly funny, and mostly setting-neutral.

How to make this good:

• Don't make it your main source for dungeons, otherwise they could get same-y. Make it one of the tools you turn to when short on time or inspiration.
• Replace the oddities with new ones as you roll them.
• Make sure the factions interact. Give them competing or mutually beneficial goals. 
• Probably replace factions as you roll them unless you want them to be recurring in the campaign.

I've been feeling down on myself lately for focusing on the "wrong" things: tools instead of ideas. I spent lord knows how long on this thing, and in that time I could just have written one solid, unique dungeon that could occupy my players for weeks. I look at someone like Patrick Stuart who seems to mutter incredible D&Disms in his sleep and think to myself, "Why not me?"

Which is pointless. I should be happy that I'm able to come up with anything original at all.  A lot of creativity is just tricking yourself into coming up with something, and artificial structure can help. That's one reason the entire OSR is built on random tables. So if I have to make a "dungeon generator" instead of just a dungeon to force my brain to work, so be it.

Anyway, the tables:

1. d20 Purpose

1. Sewer
2. Palace
3. Prison
4. Fortress
5. Maze
6. Ruin
7. Hideout
8. Pleasure dome
9. Archive
10. Garden
11. Museum
12. Workshop
13. Tomb
14. Cave
15. Temple
16. Monastery/cloister
17. Observatory
18. Market
19. Zoo
20. Roll twice: was this, now that.

2. d20 Factions

1. Tribe of trained comb jellies standing guard long after their trainers have vanished.
2. Serpent cult. Hates limbs of all kinds. Will remove with prejudice.
3. Den of thieves, too fearful to have stolen a thing in their lives, eager to goad others into the act.
4. Hiddenmen, who would die of shame if seen by anyone. They live in darkness and solitude. Desire word from their families.
5. Missingmen, who are never where they should be.
6. Minutemen, who exist one minute ahead of everyone else.
7. Corvid librarians-errant hunting for stolen books.
8. Hunger artists staging an installation. Hunger pangs, food spoils around them.
9. Ennui-mancer and her apathetic thrall.
10. King in exile disguised as fool, fool disguised as king, and other members of his entourage disguised as their opposites.
11. A sect of hedonists, against repression of all kinds.
12. The wedding party of a manticore (willing) and sphinx (coerced).
13. Mirrormen, who are what they meet. They hate this, and take it out on their "reflections".
14. Old Miser, a dragon who believes she owns all she sees, including the players. All gold serves her.
15. The corpses of a noble hunting party who do not realize they are dead. Will hunt nearly anything for sport.
16. Anthracite coalems, mining mindlessly. They will mine forever and destroy everything without further programming.
17. Twin sister succubi who believe one in the party is the perfect mate for producing powerful children.
18. Entities of combusting gas in brilliant colors, brave explorers from a kingdom of pressurized cracks and fissures deep in the earth.
19. Moth dryads spinning silver snares to snatch servants of the sun.
20. A very old man with enormous wings and attendant philosophers. He wants to be rid of them, because every new theory of his origins weakens him.

3. Rooms

d4-d10	Basics	Common	Danger	Uncommon
1	Empty	Bedroom	Cell, likely guarded	Altar
2	Entryway	Kitchen	Chained animal/monster	Armory
3	Hallway	Library	Faction leader's quarters	Crypt
4	Stairs	Meeting room	Guardian construct	Fountain
5		Storage/Pantry	Faction camp with guards	Gallery
6		Workshop/Lab	Neutral NPC, possibly hiding	Garden/Greenhouse
7			Weird monster's lair	Pool
8			Faction member, possibly lost/trapped	Secret room, possibly treasure
9				Shrine
10				Statue(s)

4a. d4-d20 Complications

1. Locked
2. Secret door
3. Oil, acid, or other hazard
4. Oddity (roll on next table)
5. Dropped key, 50%
6. Alarm
7. Pit with: 1. spikes 2. monster 3. sludge 4. tunnel to random room
8. Web or net
9. Flying axe
10. Shooting darts
11. Walls close in
12. Portcullis collapses behind you
13. Spy/Thief/Assassin
14. Device controls doors in other rooms
15. Device controls nearby trap
16. All doors lock, ambush from above
17. Floor in disrepair, may collapse
18. Sleeping gas
19. One-way chute/portal to random room
20. Antimagic field

4b. d100 Oddities

1. 15’ cube room full of 9 5’ stone cubes that begin in random positions. Every 30 seconds, they shift 5 feet in a random cardinal direction.
2. 3d12 crows sit perched around the room, silently judging. If anyone says anything negative about the crows, they attack. If they aren’t bribed with food, they will inform on the party.
3. Aborted attempt at creating a homunculus servant lies strapped to an operating table. Will beg for death.
4. All chairs were once magicians. Know one extra random spell while sitting. Chairs can’t be moved.
5. All doors lock until one person pays another a genuine compliment. Partially worn motto on the wall reads, “...don't say anything at all.”
6. All set up for a black mass and human sacrifice which will begin in d4 minutes.
7. All six surfaces of this room have doors leading in. Which door you enter determines which way is down for your personal gravity.
8. All surface thoughts can be read by everyone else in this room.
9. Alloy golem ponders the moon from a perch high above the floor. Its seven limbs can reach anywhere in the room and will seek to steal any precious metals to increase itself.
10. Always bathed in eerie light. No shadows.
11. Always in magical darkness.
12. Always raining. The impossibly high ceiling is lost in clouds. Everything is slippery.
13. Anvil. Items hammered on it may only be lifted by the maker.
14. Armory of ornate weapons for the royal guard. Anyone local would know who they belong to.
15. Aviary with birds of every hue. Can be instructed to flock into portraits of everyone who has been through this room in the last day.
16. Bureaucrats collecting the blood of a recent execution to read the coagulation for portents of the coming months.
17. Big hole up or down to the next level of the dungeon, created by a corrosive but hyperintelligent slime mold.
18. Bloody Throne. Skulls placed at its feet will explain the sitter's greatest recent mistake.
19. Body farm of criminals cut from the gallows. Used for a variety of magical components and research. Extremely cold.
20. Book on a pedestal contains the consciousness of a great magician. It will contain the answers to questions written in it the next time PCs return.
21. Bridge over chasm allows only single-file movement. Gravity flips halfway across, and the door out is located on the underside.
22. Children become old, wizened versions of themselves and adults become children.
23. Corpses arranged in a ritually symbolic way.
24. Door leads back into the same room you just left.
25. Door leads to a room in another part of the dungeon.
26. Dusty alchemy laboratory houses a homunculus that will serve the PCs if brought to life with enough magic energy.
27. Everything in this room carved from fluorescent geodes.
28. Everything in this room decorated with fine spidersilk. Quite flammable.
29. Fight frozen in time from d6 hundred years ago.
30. Food rots in this room, 1 ration per turn.
31. Forge with three white-hot swords still in the fire. They will never cool.
32. Forget everything that happens in this room upon leaving unless you first sleep in it.
33. Fountain of Forgiveness. Drinking the water will cause the drinker to forget any offenses against them from the previous 24 hours.
34. Friction in this room is drastically reduced.
35. Full moon simulator. Werecreatures change upon entry.
36. Funnel-shaped floor made of sand with a pit at the bottom. Any vibration on the sand will summon the giant antlion at the bottom of the pit.
37. Gate to hell.
38. Gender-swapped versions of the PCs challenge them to a duel.
39. Ghost with a fortune buried outside the dungeon. Will give the location away for what it wants. It wants to feel the warmth of human skin one last time.
40. Gravity pulls in the direction of a random wall or ceiling.
41. Greenhouse full of sentient, carnivorous plants. They communicate only by emitting mood-affecting volatile compounds.
42. Grisly remains of a serial killer’s victims.
43. Hand mirror on a pedestal, through which can be seen one more door than the room previously possessed on a random wall. Works once per room in this dungeon only.
44. Hiding goblin promises reward if it can be smuggled from the dungeon without being seen.
45. Houses model of the solar system with the planets on tracks orbiting the sun in the center of the room, all in the correct current position. Notes on plaques for each celestial body, written as though the author had been there.
46. Inlaid trail of gold winds along a wall to the nest of scorpions adapted to prey on the avaricious.
47. Insects wage war in this room, and both sides will attempt to win PCs’ support. If captured, they will be tried for war crimes.
48. Internally-lit skulls haunt the room and get in everyone’s business.
49. Intersects with another party searching for treasure.
50. Liquor cabinet has been left open. One bottle is labeled “POISON DO NOT DRINK.” It really is poison.
51. Maze, much bigger on the inside than it appears from the outside. At its center lies a void snail shell. Smashing it creates an instantaneous miniature black hole.
52. Menagerie with only presumed extinct species.
53. Misty swamp with mangroves supporting the high ceiling. A boat will take the party to a small island where a witch will teach them voodoo in exchange for swapping an eye with one of the party.
54. Music plays, masking nearby sounds.
55. No gravity.
56. No noise of any kind in this room.
57. Noises in this room are amplified ten times in volume.
58. Nursery of toxic slugs, trained from birth in the ways of the Slow Assassin and Slime Spy.
59. Observatory recording which stars and planets influence the appearance of which demons or gods.
60. One PC leaves this room with a twin he or she didn’t have going in. Everyone now has false memories of the twin. The twin knows nearly everything about the PC except any relative’s name. If this is discovered, the twin is revealed to be a changeling.
61. Oracular fumes billow from a natural vent. Anyone breathing them in will know the result of a friend's next d20 roll, but cannot directly reveal the information. Works once.
62. Other living things in this room cannot be seen.
63. Oven. A pastry baked with malice for its intended recipient will look delicious, but will poison them. A pastry baked with love will look revolting to its intended, but will taste delicious and cause them to fall in love with the baker.
64. PCs fall in love with the first person they see in this room. Lasts until the PC leaves.
65. PCs switch bodies in this room only.
66. Pipe organ fills the room. 
67. Reflecting pool shows only the reflections of those invisible or otherwise unnoticed.
68. Reverse Midas touch. Everything in the room is made of gold, but when touched will revert to its normal material.
69. Room built sideways.
70. Room entirely different every time PCs return.
71. Room has a laugh track like a sitcom. Laughter comes from demon children trapped in the mirror who will escape if it is broken. Sometimes they may be glimpsed. They can’t wait to eat your fingers.
72. Room only exists during a full moon.
73. Schools of fish regularly swim through this room. Sometimes sharks.
74. Secret entrance into and out of dungeon.
75. Seemingly endless pillared hall, echoes of footsteps resounding. In the shadows changelings hide, hoping to split up tresspassers and take their stuff.
76. Set of curved ritual dissecting blades, gleaming gold.
77. Shadows become unpinned from their bodies in this room. The longer PCs are in the room, the less the shadows remember belonging to anyone and the more murderous they become. They know inversions of every spell their bodies knew. It takes a week to regrow a shadow, during which time PCs can’t refresh spells.
78. Site of a horrible demon-summoning ritual.
79. As above but the demon still inhabits an innocuous-looking object in the room useful to one of the PCs.
80. Site of a recent fight.
81. Site of an ancient murder. Blood is still fresh and may take the form of the murdered.
82. Solitary magician searching for the hands of a murderer.
83. Stage. Ghosts ask you to reenact important scenes from your life.
84. Staring into the mirrors of this room, anyone plotting harm against you will appear behind you in the reflection.
85. Table set with lavish feast. Harmless.
86. Talking with the portraits will reveal one dungeon secret.
87. The darkness is carnivorous. Anyone unlit will take 1 HP damage per round, and items in darkness will disappear.
88. The furniture is made of living snakes and sometimes moves of its own volition.
89. The ghosts in this room like to play practical jokes.
90. The longer the PCs stay in this room, the more angry they will get with each other.
91. The mice in this room put on moving renditions of Shakespeare’s tragedies.
92. The more you walk towards something in this room, the farther away it gets. You can only get around by walking backwards.
93. The wine cellar of a long-dead magician. The wine is marked with spell names in dead languages. Drinking an entire bottle functions as casting from a scroll.
94. Time in this room passes at half or twice the rate of the outside world.
95. To reach the other doors in this room, PCs must traverse the walls and ceiling on impossible Escher-style stairs. If they don't believe the stairs will work, they need to climb, but if they do believe they have no problem.
96. To-scale cutaway model of this dungeon. Moving things in the model will move them in real life.
97. Trapped giant unable to remember how it got itself into this tiny room. Will allow PCs free use of its castle in the clouds if they help it escape.
98. Walking through a half-sized door in this room, you will emerge mouse-sized out of a hole in the wall elsewhere in the school. Returning through the same hole is the only way to regain your size.
99. Walkways lead from the twelve doors into this circular room to a central platform. Flesh-eating maggots clean the bones of unfortunate adventurers below.
100. Within sight of this rust-weeping statue, metal armor makes it easier to be hit. Subtract armor from base AC instead, or whatever is appropriate.