(An Italian translation of this post is available on Dragons’ Lair)

The Dungeon d100s is a series of six tables that will appear here over the next six days. Each will provide 100 prompts for creating an interesting dungeon. The tables are not necessarily meant to be used in tandem. A dungeon forced to include one more more results from all six of them would likely be an overstimulating, unplayable mess. Better to pick one or two tables, or even roll a d6 to determine which of the tables you roll on, then employ your own creativity to build out from the result you get. If a result doesn’t spark your own creativity, reroll.

This first table is the most general. At various times it has been called d100 Dungeon Origins, d100 Dungeon Gimmicks, and at one point simply d100 Dungeons. At least two of the six tables in the series budded off from this one when I realized far too many entries revolved around the same shtick. At times I was tempted to split even a third table off from this one, but 600 prompts has proven to be the hard limit of my creativity. Thanks are due to my sister Veronica Whelan for proofreading this colossus.

Good dungeons are places in decline. Knowing their original purpose is useful both before and during play as a creative prompt, but it is essential in my view that the whole dungeon cannot be united in its purpose. Dungeons are wild places. Places where players can get into shenanigans, where they can do violence, and not be immediately rebuked from all sides by a united front of defenders. If a place is active; held in whole by a single faction, then the mode of play is dramatically different. The players are storming a fortress, not exploring a dungeon. Both activities have the potential to generate fun play situations, but are so different from one another that I don’t think they can be usefully discussed in the same breath.

The Dungeon d100s
1 – Themes
2 – Structures
3 – Rewards
4 – Doors, Floors, Walls, & Ceilings
5 – Factions
6 – Locks & Keys

Bonus – Auto-roller, at Liche’s Libram.

d100 Dungeon Themes:

1. A palace made entirely from sea foam, which comes into and out of existence with the tides. Inhabited by folk who are able to survive the transition.
2. The folly of a forgotten ancient civilization, jealous that none of their accomplishments were listed among the wonders of the world. They built this labyrinth in hopes that their architectural ambition would be recognized, but it never was.
3. A magical board game which the party has been drawn into. The game may have rules or random events which don’t conform the laws of normal reality. Leaving the game may be as simple as reaching the exit, or require completing arduous win conditions.
4. An alternate version of some familiar game space. Perhaps the tower of a friendly wizard, the party’s home city, or their own citadel. The place may have fallen into chaos while they were away, or may be mirrored in an extradimensianal space, or be fully recreated elsewhere for some mysterious purpose.
5. Alive, in the same sense that an intelligent magic item is alive. The dungeon has a consciousness, and a will. New corridors and rooms sometimes appear as it becomes stronger, and it seeks to better itself further by accumulating greater hordes of treasure within itself.
6. An in-game version of a real world location that some or all of the players would be personally familiar with. A local grocery store, church, school, or someone’s current or former home. It may need to be altered to function as a useful dungeon, but the players ought to be aware of its origin so they can use their real world knowledge in play.
7. A holy site built in ancient times by a religion which still exists today. It was ceremonially sealed to mark the end of some forgotten religious schism. What few pilgrims still visit must be content to make their prayers at the entrance.
8. Mobile, requiring that characters catch up to it, or anticipate its route when they wish to enter. It may have been built on (or in) a massive creature, it might move mechanically with understandable mechanisms, or by inscrutable magics. It might walk on legs, roll on wheels or treads, hover, swim, or burrow. Its movement might be destructive or not, intentionally or unintentionally. It might have an operator, or follow a per-designated program, or simply have gone rogue. It may be new or ancient: a familiar sight, or something unexpected and frightening. When the players leave, they could be quite far from anywhere they’ve ever been before.
9. Flying high in the air, requiring some effort for characters to reach it. Its flight may be slow and drifting, or swift. It may be stable in the air, or in the process of falling, or there may be something the players can do within the dungeon to cause it to come crashing down.
10. The colossal pleasure barge of some ancient ruler. The reach of its construction exceeded the grasp of ancient ship builders, and it sank. It may still be underwater, or it may be resting in a dry lake bed, or existing in some stage between the two extremes. After being here so long it may have been connected to tunnels, or to some greater dungeon beneath it.
11. A focal point for a time fracture. Within it, the characters can travel to different eras of the dungeon’s existence. Probably a fixed number of them. Travel through time can only occur at certain fixed locations, and the players can only exit the dungeon in their own era.
12. The elaborate hairpiece of a grand lady, who contracted a wizard to fill it with tiny treasure and tiny monsters, and to shrinkify any adventurers who want to brave the danger so she can show off during the grandest party of the season.
13. The death palace of an ancient conqueror queen who demanded that each of her subject people’s build a grand home for her. This particular one was filled with confusing corridors and traps, in the express hope that she might visit someday.
14. Permeated by extreme temperature: perhaps very hot, in which case armor is dangerous to wear, metal objects are dangerous to touch, and copious water rations are needed. Alternately it may be very cold, in which case layered clothing is necessary, floors will often be slippery, and important details may be obscured by ice or snow.
15. A defense built by a subterranean civilization. They dug ever upwards, not realizing until too late that eventually the solid earth would give way to a terrifying sky. Believing they had discovered hell, they built this place to prevent any horrible surface creatures from reaching the wholesome lands below.
16. A training ground for a creature which predates on humans. Their young must learn to hunt perfectly in controlled conditions, lest they make some mistake which reveals the creature’s existence to human kind. People are lured to this place with rumors of hidden riches.
17. A facility for the creation of new forms of life. It may be a naturally occurring spot where evolution is wild and rapid, it may be God’s own workshop, or it could be the magical or scientific laboratory of an ambitious mortal. In the latter case, there must have been some intent: to replace people with clones, to produce an army, to satisfy a god complex, etc.
18. An afterlife, which was once a paradise for the adherents of faith now long forgotten. The gods who made it are dead, asleep, or so weakened they can no longer justify the effort of maintaining the place. Many of its pleasures have turned to horrors, and much of its boundless space has collapsed into the ether between realities.
19. The former hive of an extinct colony of giant architect ants. The spaces are more complex and intricate than one would expect of a typical ant, but retain a naturalistic quality.
20. A small cog in the mechanism of reality. If the birth and death of the whole universe is a cycle that takes ten billion billion years, it is only because its cycle is powered by other cycles which turn more rapidly. This place is born, dies, and is reborn within a mere few hundred years, and is presently in a state of collapse. Even as the player characters plunder it, parts of it will cease to exist around them.
21. The extra-dimensional retreat of a long dead wizard. It is located on another world, and enjoys grand views of beautiful vistas. The exits all lead back to our world however, as this planet is entirely inhospitable to all familiar modes of life.
22. The habitat of a unique species of creature that lives nowhere else. They are not hostile, and may not even know how to respond to violence. Their presence alters the typical dungeoneering experience in a major way: perhaps they scream when they see light, or exhibit a natural anti-magic field, they may excrete a slippery or sticky substance on every surface, or be naturally inclined towards serving as mounts.
23. A mysterious structure which appeared overnight, and occupies a much-used space. It may be sitting in a farmer’s field, or in a town square, or perhaps its appearance has displaced other structures whose inhabitants are missing. (Did they go wherever their homes went, or are they in the dungeon?) Alternately, the dungeon might have formed itself around existing structures, such that their inhabitants are now trapped in their own homes.
24. A towering lighthouse, abandoned after an ancient catastrophe sundered the earth and caused the shore to move hundreds of miles away.
25. The studio of an eccentric artist who stumbled into being considered a “genius” by wealthy elites. This person dabbled in every medium, indulging every depraved and harmful instinct in the pursuit of novel modes of expression. When they passed, their multiple wills created such a tangle of confusion (another attempt at unusual artistic expression) that the descendants of the original beneficiaries are still arguing in the courts.
26. A snowy mountain resort for affluent guests. It may have been a ski or hunting lodge which has fallen out of fashion, and gone many years without proper maintenance to protect it from the bitter cold.
27. A secluded island or private stretch of beach which was once a popular destination for wealthy people on holiday. Nearby is a severely depopulated service village where the help was left to fend for themselves. They resent living in hovels and penury while all this wealth has sat abandoned for decades. They’d move in if they could, but the owners left many dangers behind to “protect their property.”
28. A great multi-level stable. The folly of an obscenely wealthy aristocrat who loved horses more than they loved people. Much more.
29. Someones unconscious mind, which has been temporarily manifested as a series of rooms and corridors. It may be the psyche of a king, a demigod, or a player who happens to be absent for this session. Within are creatures that represent the character’s hangups, insecurities, and defensiveness. The treasures may be their secrets, spells, or access to levers which control their feelings in some way. The players might want to help this person heal from trauma, recall vital information, or may simply be taking advantage of a person who has fallen into this peculiar and vulnerable position.
30. A slaughterhouse or fish gutting plant. An industrial building for killing and disassembling meat creatures. Perhaps built in a strange way by an eccentric industrialist, or warped by angry magics.
31. An island which has only recently risen up from the sea. Its spaces are constructed of coral, lava channels, sea monster corpses, and dense groupings of strange plants which only survive underwater. If it rose only yesterday it will be teeming with dying sea life, lashing out at anything that comes near. If it rose a few years ago, a new ecology will be emerging, and the inhabitants will be migrants seeking to build a new life for themselves.
32. The seasonal villa of an obscenely wealthy bourgeois or aristocrat. They are not in residence, and so it is protected by traps and guard creatures. The deeper one delves into the villa, the more terrible depravities are uncovered.

33. In heaven there is a house waiting for each of us. Angels toil to make these homes worthy of our goodness. Recently a true saint who had earned themselves a sprawling and decadent mansion committed a horrific sin just before their death. They were cast into hell, and in His disgust God hurled their mansion away, and did not realize that it fell to earth.
34. Placed here by the gods themselves as a test for those who might wish to consider themselves heroes. Those who overcome its many challenges will earn themselves divine attention. This is, at best, a mixed blessing.
35. A great landfill where the detritus of civilization is discarded. A series of passages and chambers have been hollowed out of of the great heaps of trash, perhaps connecting further to underground tunnels or sewers. Inhabitants probably include a mystery cult of rich kids on a poverty tourism kick.
36. A titanic boulder impossibly rolling back and forth between two mountain peaks without ever appearing to loose momentum. Perhaps the spirit of Sisyphus labors on it. The dungeon within the boulder may be terribly disorienting, or may have a sort of artificial gravity to it.
37. Radiant with powerful healing energies. Any living creatures within the dungeon gain fast healing 20, though this only applies to injuries sustained while inside the dungeon. This makes both the player characters, and the inhabitants they may come into conflict with, functionally invulnerable. Violence will not effectively solve problems here.
38. An active factory whose interior is a mystery. The dungeon’s produce simply emerges, and is taken for granted by those who collect and use it. Alternately, the factory dungeon may take input, but give no output. People may continue to load coal onto a mysterious conveyor belt simply because it is a traditional ritual.
39. So high tech as to be impossible for the player characters to comprehend. It might be an alien vessel or space station, or an anthropological observation post. It is destroyed, abandoned, and at least partially reclaimed by nature. There may or may not be some survivors left behind, some bits of technology could still work, a clever person could learn a lot from studying this place, and potentially advance their own culture’s technological abilities.
40. Santa’s Workshop, or the lair of some other folkloric character. The burrow of the Easter Bunny, or the sky castle of the twelve merry goblins of [insert setting specific holiday here]. The more out of season it is when this dungeon is delved the better. It might be properly abandoned, or perhaps the mighty folkloric creature is hibernating until their appropriate season. Perhaps each year they wake up and spend a week sweeping out all the squatters who settled in their home while they slept.
41. Builder Beetles were born from a poorly-worded wish, spoken by a dying architect who regretted never being responsible for any truly spectacular structures. Where they come from before they do what they do, and where they go after they’re done, is a mystery. They appear in small human settlements, drive everyone out, and build. Great walls and ceilings over the whole town, connecting existing buildings with elaborate tunnels and sky bridges until the whole village is a dungeon. Humans rarely want to live in the spaces the Builder Beetles leave behind, but for other creatures it is a very convenient domicile.
42. Noah’s Ark (or perhaps the arc of Ziusudra, Atra-Hasis, Utnapishtim, etc). A great vessel large enough to shelter a breeding stock of all the world’s land animals during a great flood, which came to rest on the top of a mountain when the water receded. It still rests their, perhaps filled with the descendants of those unrecorded creatures who chose not to disembark with the rest.
43. A legal library, for The Law is sacred, and its sanctity depends on its secrecy. Only the arbiters could ever know The Law, only they could study and interpret its precepts. To maintain the purity of The Law, it had to be housed in a labyrinth beneath the city, with entrances known only to the arbiters, so they could disappear to consult the law, and reappear to render their verdict wherever their intercession was needed.
44. A woodland where the trees and bramble grow so thickly they might as well be walls surrounding ‘rooms’ and ‘corridors’ that were carved into existence by an ancient and secretive religion.
45. A test of maturity, constructed bit by bit by the girls of the People at the Foot of the Mountain became women. Before any girl could seek a mate and a home of her own she must present a plan for a new corridor or room, then build it with her own two hands. She may be instructed, but never aided. Many began their work quite young, as it could take years to complete an ambitious addition. The temple is so sprawling now that no complete map of it exists, and all manner of creature have settled in long neglected sections.
46. An abandoned train yard. No active rails even connect to this place anymore, and the rusting hulks are scattered pell mell about the place.
47. The work of true artisans. Folks who believe in craftsmanship for its own sake. It should not matter whether anyone will ever see a thing, one should still labor to make it as beautiful and sturdy as they possibly can. The result of your work should stand apart from every other example of its kind because even if other people don’t see it, it will be appreciated by god who sees everything. Even this sewer system.
48. A trap for humanity, eroded into existence by spiteful water spirits who do not appreciate the haphazard way their essence is often drawn up to the surface via hateful human wells. The spirits deposited many noxious fungi, amphibious carnivores, and subterranean treasures here.
49. An active temple for a god of foolhardy death. Attempting to plunder the temple is an act of religious devotion. The priests say that even if you don’t die, taking such risks is an act of prayer that will surely be heard by their god. Others contest that there is no such thing as a god of foolhardy death. They argue instead that the priesthood is cover for a demonic cult, and the dungeon is an elaborate form of human sacrifice. Sure, a few folks might make it out with fabulous wealth, but far more will perish in the attempt!
50. An abandoned factory, which may have been built to produce statuary, war materiel, print publications, worked metals, candy, etc. Much will have been left behind, but only because extracting it would be more expensive than it’s worth.
51. An arctic research station composed of multiple buildings and some excavated ice caves, all with guidelines between them to aid movement whenever thick fog or snowstorm makes vision unreliable. Unless your setting is more modern, this place is likely the caprice of a wizard who believed there was some ancient wisdom hidden nearby, or the former home of some hero who was cursed to be unable to endure warmer climes.
52. A mystery. A few years ago the people of a nearby village all blacked out in tandem. When they awoke, there was the dungeon. The callouses on their hands told them they had done the work themselves. Years had clearly passed, and those who had been too young or too old to work were found long dead from starvation. With nowhere else to go the people resumed their lives, but it is a trauma none of them will ever overcome, and they make a concerted effort never to look at the structure they don’t remember building.
53. A forgotten showcase structure, built in collaboration between various guilds of artisans to demonstrate their skills, and serve as a unified guild hall and catalogue for potential employers.
54. A cold, cold revenge from the dinosaurs. Their sages foresaw the meteor which heralded their destruction, and could find no means by which to avoid death. They foresaw also that the planet would come to be dominated by disgusting ape creatures. The final years of their race was spent building this place, and placing their greatest treasures within it so as to better tempt as many of the ape things as possible to their deaths.
55. An archaeological dig of massive scope, abandoned perhaps due to lack of funds, or because it released something it should not have. The rooms are semi permanent living structures, and partially excavated buildings.
56. A sort of rat’s maze built by a cosmic entity who wishes to observe and rate humanity’s quality. This is not hidden. Everyone knows that when you enter this dungeon you will be watched, and tested. The tests are often different, and are rarely fair. People attempt it anyway because the “cheese” at the end is a legitimately bounteous treasure.
57. An ancient military base. Perhaps a grand permanent campus with parade grounds, thick walls, and offices for generals. Alternately it may have been a frontier structure, built in haste to to withstand brutal assaults.
58. The refuge of a wealthy and powerful old man who suffered a public embarrassment so severe that he decided to build a miniature city for himself, populated by his servants, where he could live out his final days. It was inhabited for a scant few years before he died. No one else ever took up residence, as it was in a terribly inconvenient location, and managing its great size would have been an absurd expense.
59. Formerly a political prison. A place where the ruling elite could cause enemies of the state to disappear, “convince” them to turn against their comrades, and put an ultimate end to their disloyalty in some efficient and satisfying way.
60. An artificial tiered garden out in the middle of a desert. Unless there is magical watering at work, the plants will have long ago died from lack of imported water. Only native desert plants grow here now, though some invasive plants may have survived by eerie mutation. Within the garden’s tiers are a series of chambers originally meant for maintenance staff and visiting guests.
61. An elaborately ornamented temple built by a short lived religion which worshiped some particular animal. It could be any relatively simple animal: iguanas, penguins, beards, crows, flamingos, etc. The whole place exudes big Horse Girl energy.
62. A time capsule built beneath the foundations of the city, and intended to be opened on the 1000^th anniversary of its founding. It was intended as a showcase of the city’s original culture, and to play a few pranks on the naughty future-folk. Doubtless, the past thousand years have seen a few other creatures sneak their way in via unintended means.
63. An ancient race track, or other sports stadium. The field of play will likely have had other structures built within it by the dungeon’s current residents, and will likely also contain chambers that were intended for food vendors, green rooms, announcers, VIPs, perhaps even an attached palace.
64. Intended to trap a terrestrial god, built by a sect of that god’s worshipers. They came to believe their god had a hellthorn in its paw, which they wished to remove. As such the dungeon is in all ways designed to show respect to those it traps.
65. Formerly a school of some kind. It may have been for primary education (elementary, high school), higher education (university, philosophy, science), trade education (culinary, carpentry, cosmetology, medicine, law, military officer), spiritual education (seminary, martial arts dojo), or something fanciful (necromancy, spying, assassination). It may have been abandoned because it lacked funds, due to fallout from some horrible scandal, or simply because the civilization which built it is long extinct.
66. The first draft of hell. Eventually more capacity was needed, as well as updated security since a few souls had managed to escape. All the damned souls and devilish tormentors are long since moved on to better facilities.

67. The dungeon is a metaphorical space. Different rooms and creatures are representations of places and people. There are clues to what the various elements of the dungeon represent, but the connections are not always obvious. None the less, actions taken in the dungeon will be reflected outwards. If the party were to meet a goblin who represents their house, for example, and they killed that goblin, they might return home to find their house had burned down.
68. A zoo, aquarium, or menagerie. Presumably the animals have either escaped, died, or become mutated in some fashion.
69. An enchanted pleasure palace wished into existence by someone long dead. The magically created servants within have split into factions over whether they want to kill anyone who visits the palace so they won’t be compelled to serve any more, and those who miss having someone to serve, and wish to trap visitors so that their lives can have purpose again.
70. An intact suburra from the ancient world. These were a sort of ancient apartment buildings. The bottom floors would be businesses or upper-middle class homes. The higher floors were rented by poorer and poorer people as you went up. Given that these buildings were notoriously prone to fire and collapse, this one most likely survived either by being buried, or by some preservative magics.
71. A testing ground built by order of a capricious prince who declared he would only marry the person who could retrieve the treasure from the dungeon’s center. Legends say he never did marry, so presumably that treasure would still be there, right?
72. An ancient library assembled by a philosopher king, who made it their goal to record and collect all the knowledge in their world. Its treasures include many alternate versions of texts which are still well known in modern times, as well as lost literature, history, and science which may or may not have been rediscovered since it was lost. Unfortunately for looters, much of this writing is on great stone tablets which are incredibly difficult to move, and much of the rest is on scrolls which crumble to dust if touched.
73. Laid out in an incredibly precise shape. Its structure forms a magic sigil that was used in an ancient and dark time in a grand summoning ritual which created the sun.
74. There is a member of the royal family who was so mean spirited, ambitious, and stupid, that they were eventually exiled to a small island. Great care was taken to ensure all the perquisites of their royal rank remained in place, save only their freedoms of movement and association. They could never leave the island nor have contact with anyone not personally approved by the king, but were otherwise left to enjoy a life of excess however they saw fit. This is all ancient history, and now this island prison / pleasure palace is a dungeon filled with all manner of creatures. Alternately, it may be that the king has only recently died, and their will stipulates that this troublesome royal must be assassinated to prevent future troubles. The player characters could have been hired to do the deed, or to smuggle the prisoner off the island to safety.
75. A place which predates the world. It floated through space for eons, gradually accumulating bits a space detritus, until its gravitational mass was great enough that it formed a rogue planet, and eventually fell into stable orbit around our star.
76. The interior of an inscrutable tool which was left here by a creature beyond our understanding. It could be God’s anvil, or Yog-Sthoth’s power loom. Though, obviously, the names of human tools can only vaguely approximate the scope of this thing’s function. It may have been left intentionally, or dropped and forgotten. Some of its functions could potentially be manipulated by player characters to produce strange results, or the things it does may be entirely beyond human ability or understanding.
77. A laboratory in which a wizard or scientist conducted various atmospheric and ecological experiments. One room may emulate conditions of an arctic tundra, while another is meant to simulate a rain forest. Hazards might include tornadoes, hurricanes, floods, etc.
78. An embassy built when humanity was at peace with a strange race who had strange needs. Perhaps sea creatures who needed to be submerged in water to live, sky creatures who could not breathe our thick air, or burrowing creatures who could not abide the light. This place was built to accommodate their needs, and facilitate better relations between the two peoples. Peace has long since broken down, and the two races have parted ways. The embassy still stands, though. As hostile to human life as it was adapted to theirs.
79. A former senate house or parliamentary building. It contains a large space for collective lawmaking, and ancillary spaces for offices, ceremonies, meetings, and other amenities peculiar to the culture who built it.
80. Crafted for no particular reason by a wizard who had created a peculiar nightmare-scanning device, which enabled them to construct real versions of the imaginary spaces those nightmares took palace in, and link them together. The complex connected dozens of dream spaces before the wizard realized there was actually no point to this activity, and moved on.
81. Created by and for very small creatures: rat sized rat people rearranging sewer pipes, or intelligent viruses building a citadel within a human body, or pixies hollowing out trees and boulders. The player characters will need to shrink themselves to enter the dungeon. They could perhaps just destroy it if they wished, but doing so would likely destroy any treasures contained within. (After all, such treasures are likely to be art, magic, or information. One does not plunder a minuscule dungeon looking for great heaps of gold!) It should also be noted that tiny folks are well acquainted with the tactics and defenses necessary to protect themselves against giants.
82. Created by and for very large creatures. Everything in this dungeon is far too big for the player characters. Stairs and furniture require difficult climbing to navigate. Note that just because it was built by large peoples, does not mean they are its only inhabitants. They may not even use it at all anymore.
83. A prison constructed according to some armchair philosopher’s notions of how to reform undesirable peoples. Perhaps it is filled with challenges, on the belief that overcoming them would make a person deserving of reentering society. Perhaps it is built on the idea that isolation, medical torture, or constant observation would best ‘fix’ a person.
84. A great complex tree house, possibly built by long gone elves, or long dead architects attempting to survive whilst marooned on an uncharted island.
85. A medieval monastery of the western style, built for the outwards appearance of maintaining a simple life of prayer and holy labor, while allowing the monks some privacy to indulge in sinful luxury. Perhaps more privacy than usually was provided here with great chambers hidden underground for all manner of decadence.
86. A performance space built for the delectation of the upper classes, with greater social rank allowing access to lower chambers where ever less socially acceptable art is performed. At the lowest levels, the performers themselves rarely ever came out again.
87. An important cultural site for your people. Your ancestors built it and used it, but at some point chose to abandon it. Until recently it was fairly common to visit the place and view its wonders, leaving offerings to the ancient dead where appropriate. Recently, a colonial power has brutally dominated your lands. They’ve declared this place to be an archaeological site, and forbidden your people from entering it.
88. A high class casino where the highest of high stakes bets were placed. It was transformed into a dungeon by a really, really foolhardy bet which went very poorly.
89. The maintenance corridors of a massive inscrutable machine, the engine of a natural process. Perhaps this dungeon is what turns the sun and moon in the sky, what controls the tides, the passing of the seasons, or the birth of heroes. It may even be an engine of destruction. God’s own fail-safe in case creation ever gets out of hand. It may or may not be possible for the players to make minor alterations without completely disrupting the machine. Perhaps it is broken before they arrive and they wish to fix it. Perhaps they can radically alter the nature of their world with some ill-advised tinkering.
90. The exterior of a titanic creature. A mega-elk, ur-mammoth, or humaniform colossus. There is a whole ecology across—and even within—their body. Pockets and purses are like rooms, fur is a forest, whole settlements could rest on their back or hang from their underside.
91. Knowing they would be conquered when the next campaigning season began, a whole civilization dedicated themselves to building this dungeon. They sold their souls for the necessary magics, and heaped the whole treasures of their history in a room that is visible from the entrance, but protected by a great and impenetrable wall of death.
92. A petrified egg from which a god would have hatched if it had been properly tended. The dry yolk still forms the center of the dungeon. Alternately, there may be a creature which gestates in dungeons is if they were an egg. Protected by the shell of the mythic underworld, nourished by the yolk of the dungeon’s inhabitents once its digestive tract develops.
93. The labyrinthine halls from which the enforcers emerged, dragging criminal wrongthinkers into dark rooms from which they rarely emerged. The space connects here and there, and contains many unpleasant places now settled by creatures less horrible than the enforcers were, though that is not a high bar to clear.
94. Shelter built against a civilization-ending cataclysm which never came. Or perhaps did come, was survived thanks to the shelter, and is now only long forgotten history.
95. A facility for containing creatures and objects with dangerous abilities and unknown purpose. There was a breakout long ago, so many of these things have since escaped into the world and may even be widely considered normal today. Perhaps, before the breakout, nobody ever got cancer, pregnancy and birth were trivial affairs, and the human lifespan was triple what it is now. Some safeguards and some anomalies are still here and still dangerous. The world is a better place for not being subjected to the influence of those which are still secured, contained, and protected. Whilst exploring this dungeon, the characters should certainly encounter clues as to how the world was better before certain anomalies got away.
96. A reverse tower, hanging down from the sky of a great underground cavern. Alternately, a sideways tower, straight out from a cliff face. Gravity may or may not be reoriented within the interior.
97. Sailing ships clustered together and left unattended. They may have all run aground on an uncharted island, or been discarded and left to rot together in a shallow bay, or forgotten in the secret dry dock of a fallen military power, or abandoned in the shipyard of an insolvent corporation.
98. Constructed as a habitat for an endangered creature with a sensitivity to something which has been magically warded against. Perhaps light kills them, so the whole dungeon is shrouded in magical darkness. Alternately the whole dungeon may be under a zone of silence, an anti-magic field, or have a robust automated fire suppression system.
99. The world ship on which ancient human colonists arrived on this world. Malfunction caused it to crash, and those who made it to the escape pods are our ancestors. It is a history so thoroughly lost that no human even suspects we did not originate on this world.
100. The famous money hole. Of late it has become a fad among the wealthy to flaunt their excess by throwing larger and larger amounts into a deep natural shaft. The more a person can afford to discard, the more affluent everyone assumes they must be. Of course, the hole itself is heavily guarded to prevent any dirty poors from misappropriating the discarded funds and unbalancing the economy. Perhaps creatures have also been set loose below to make recovering the treasure even more foolhardy, or creatures may have come up from the underdark to fight over this great heap of treasure. Regardless, there might be some other way into those caves.

Can you believe that titanic tirade is just one sixth of what I’ve written for this series? I mean, the entries in this one are particularly verbose, but none the less, dang.

Also, All Cops Are Bastards.