If I ever get around to designing a megadungeon, it'll probably be this one. This is a concept I've been toying around with for some while, mainly inspired by stuff like At the Mountains of Madness, Skeleton Jelly, Centerra, and the Mystery Flesh Pit National Park. I originally wrote it with a fantasy setting in mind, but it works for a sci-fi or even modern day setting just as well. I can see this running on Old School Essentials as easily as Delta Green or Mothership.
|artist: Paul Carrick|
For Ubbo-Sathla is the source and the end. Before the coming of Zhothaqquah or Yok-Zothoth or Kthulhut from the stars, Ubbo-Sathla dwelt in the steaming fens of the newmade Earth: a mass without head or members, spawning the grey, formless efts of the prime and the grisly prototypes of terrene life . . . And all earthly life, it is told, shall go back at last through the great circle of time to Ubbo-Sathla.
—Clark Ashton Smith, "Ubbo-Sathla"
The Slimelord is known as: 1.: the Slimelord, 2.: Ubbo-Sathla, 3.: the Large Indo-Pacific Disturbance, 4. Father, 5. the Active Crustal Biolayer, 6. Abhoth, 7. The God Without a Face, 8. LUCA, 9. Mother Earth, 10. Progenitor and Inheritor.
What is invariably true of the Slimelord is that it is a protoplasmic organism of immense, unimaginable size. An amoeba the size of a moon, an ocean of ooze, a continent of slime.
|artist: Wayne Barlowe|
It defies study and categorization much in the same way a whale defies a fisherman's net - utterly and completely, by sheer difference of magnitude. No one can possibly know how old it is. No matter how far you look back in time, it seems to have already been there. Someone will invariably believe it might be the originator of all life.
Here's another thing that is invariably true of the Slimelord. In the old days (depending on your setting's cosmology, this might mean anywhere between five thousand and five hundred million years ago), it bubbled up from the cracks of the earth to devour the surface in an indomitable tide of slime.
And something stopped it.
|artist: Jason McKittrick|
Again, the exact form and origin of the Precursors depends heavily on what setting you want to drop the Tombs into. What matters is that they were civilized beings who lived a long, long, long time ago, they had magic or technology in stupendous excess of what your PCs' home culture can understand, and they disappeared into the sands of time so completely that only the murkiest myths, if even that, remain of their memory.
The Precursors were: 1. aliens resembling crinoids, 2. lizardfolk, 3. the gods themselves, 4. self-improving machines made by even older precursors, 5. the dinosaur-people who ruled the Earth before man, 6. the lost civilization of the orcs, 7. sapient colonies of coral, 8. the Great Race of Yith, 9. the very first vampires, 10. Neanderthals.
Their civilization was in its heyday when the Slimelord washed over the world in order to subsume it into itself. In response, the Precursors gathered up their most world-shattering magics, or their clarkest of clarketech, and annihilated the Slimelord, shattering it into a billion pieces.
The Tombs of the Slimelord
This place is a message... and part of a system of messages... pay attention to it!
Sending this message was important to us. We considered ourselves to be a powerful culture.
This place is not a place of honor... no highly esteemed deed is commemorated here... nothing valued is here.
What is here was dangerous and repulsive to us. This message is a warning about danger.
The danger is in a particular location... it increases towards a center... the center of danger is here... of a particular size and shape, and below us.
The danger is still present, in your time, as it was in ours.
The danger is to the body, and it can kill.
The form of the danger is an emanation of energy.
The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.
The Precursors were one of those civilizations who tended to think in terms of eons, not mere decades or centuries. The Slimelord may be defeated for now, but its selfsame fragments would surely reconverge at a later time, threatening all life again. So the Precursors undertook the construction of a vast, subterrene prison complex, designed to keep the myriad droplets of the Slimelord separate. This gigantic, ancient compound is the Tombs of the Slimelord.
Tombs, in plural, not just a single Tomb. Most of the dungeon is taken up by thousands upon thousands of isolation chambers, each purposely designed to keep a single fragment of the Slimelord - a slime - contained. Each chamber is different, uniquely designed. Some are the size of a single room, others are the size of a city. Some are simple prison cells, others are devilishly complex behavioral traps. The Precursors had an intimate understanding of the Slimelord, and knew how to keep each bit sequestered away.
This sprawling aggregation of slime prisons comprises the overwhelming majority of the Tombs' interior. The rest is maintenance accessways, weapon storages, and other auxilliary areas. The entire complex, taken together, is almost inconcievably massive - a megastructure buried beneath the earth. A dungeon the size of Australia.
The prison of the Slimelord is not only huge. It is also old; very, very old. If your setting has such a concept, it is geologically old. It was already underground when it was created, and the intervening epochs piled even more rock layers on top of it. It has weathered the slow grind of tectonic plates, supervolcanic eruptions, earthquakes and asteroid impacts.
Survived them - but not unharmed. The heavings of earth's crust have bent, warped, cracked and broken the ancient superstructure of the Tombs. Accessways disappeared between closing-in walls. Entire sections collapsed in on themselves. Sinkholes opened between different levels, the brickwork falling away and shattering a kilometer below. In some places, geologic processes opened entrances into the Tombs, a prison that was never meant to be entered - or exited.
In effect, the Tombs are leaking. Every so often, an infinitesimal fragment of the Slimelord escapes from its chamber, wandering off into some cave system, or even getting out onto the surface. If your setting has slimes (black puddings, gelatinous cubes etc.), this is where they all come from.
Yet other slimes have not yet escaped, but found each other inside the ruined areas of the Tombs, uniting into something bigger, more terrible. Ruined chambers and corridors are frequently prowled by these re-ascendant Petty Slimelords, thrashing their way through the dilapidated containment chambers and looking for more biomass to add to their own. They aren't just really big slimes. They are more, worse, more complete. Tekeli-li, tekeli-li...
And Now, Some Roll Tables
1d10 entrances into the Tombs
- An eruption shakes the island to its core. The volcano collapses in on itself. After the catastrophe, a cubical chamber is found in the side of what used to be the caldera.
- An eons-old spell scroll, written with a reed stylus on undecaying calamite parchment, opens a portal into the Tombs. It is single-use.
- A colossal, round capstone stoppers up the lunar lava tube the expedition descended into. Besides the stone, the lunar soil can be excavated with some work.
- The find of a lifetime! In the bottom of the dig pit, a narrow artificial borehole shoots down into Carboniferous rock layers. The interns are apprehensive, but the professor will hear none of it.
- An oozing abomination burrowed out of the ground and laid waste to the surrounding village; the intervention of a cadre of knights spelled the doom of the beast. The hole it emerged through gapes blackly in the town square.
- The urban legend proved true: Atari really did bury thousands of video game cartridges in a landfill! Below the excavated copies of E.T. the Extra-Terrestrial, the landfill continues in an unheard-about crack downward.
- The planetary survey mission found the site two cycles back: a landscape of menacing basalt thorns, a huge black stone slab in the center. On the slab, monumental graven runes and bas-reliefs of screaming alien faces can be seen.
- The brass is nervous. Ground sonars have revealed an excavated structure of unknown size underneath the Nevada Test Site. Could this be a secret communist lab, spying on American nuclear tests? The drills are revving up.
- The entrance yawns deep within a cave system, well out of the way of the usual spelunking routes. An underground river waterfalls into the hole, flooding the antechamber.
- The dwarves are gearing up for war. Something reached up from their deepest quarries and swept their mining outposts clean of all things but rock. The mineshaft has been dynamited until the soldiers are ready.
1d10 reasons the PCs are in the Tombs
- The Company has a big trade in slime-derived products! Cosmetics, alchemical ingredients, industrial solvents. Prospecting contracts pay a fortune.
- The Precursors were great, they were wise. No one remembers them anymore, except you and your religion. Their labors must be upheld. The Tombs must be assessed and resealed.
- The Precursors were fools, enemies of the inevaitable. They are gone now, and so too will all their works. The Tombs must be cracked open, the Slimelord unleashed.
- The local authorities are getting uncomfortable about the giant sinkhole that recently opened into some sort of underground structure. Go in there and see what's inside.
- Few survived the day the ground split open and swallowed the colony whole. The ceiling is collapsed, there is no way back. Only forward, and hopefully out.
- A kooky but renowned archaeologist wizard is looking for bodyguards for his venture into the Tombs. He is learned, pampered, and rich.
- Welcome to the Ordovician Palaeoarchaeological Site! I will be your guide for today. For your own safety, please stay on the marked path and follow my instructions. Enjoy the tour!
- This was just supposed to be a geological survey. This was just supposed to be a geological survey. This was just supposed to be a geological survey.
- The Slimelord has returned! It tides over the earth, threatening life once more. You must descend into the Tombs that once held it to learn the secrets of the Precursors, and maybe discern how it might be defeated.
- The PCs themselves are slimes. Waking to an uncertain consciousness after aeons of brainless, animal slumber, embers of purpose smolder within their thought-matrices. Reunite.
1d10 chambers within the Tombs
- A maze the size of a city, caging a single slime at the center. The ground trembles continually as unseen mechanisms constantly reshuffle the cyclopean stone walls.
- Lush forest, streams, lakes, fens. Animals composed of slime muscles on bone scaffolding live, die and prey on one another. The slime itself is distributed within the food web.
- A sprawling, labyrinthine sculpture garden. A bound demon is locked in a never-ending sculpture contest with the slime kept in this chamber; it will let the slime go if bested.
- Anyone breaching this cubical chamber is pulled into the center with nothing to grab at. Gravity spells or a magnetically-locked glob of dark matter keep the slime in this invisible, floating prison.
- Buildings, roads, sewers. Two miniature cities on each side, each housing a populace composed of the mitotic clones of one slime each. They are sapient. They are at war.
- Towering, monolithic altar, engraved with scenes of the Precursors vanquishing the Slimelord. Atop the altar, a slime bubbles and roils within a Klein bottle.
- A sluggish, dark lake, set into an artificial basin in the floor of the chamber. The slime is in solution. The animated skeleton of a plesiosaur lunges from the water to drag back any escaping droplets.
- Information center. Small chamber with library-like rows of standing stone slabs, each tightly carved with alien hieroglyphics. On the walls are engraved weapon schematics, trap plans, and a detailed map of the world as it appeared in the Precursors' time.
- Cathedral-sized, three-dimensional grid of lockers, vaults and racks, holding antimatter swords, cobalt bombs, hellfire flamethrowers, disintegrator cannons. The spears of the gods.
- An oasis. Cool watering holes, squat little stone buildings, prehistoric trees bending down with fruit. Inhabited by the far descendants of the Precursors in utopian bliss, having completely forgotten their advanced crafts or their war against the Slimelord.
1d10 guardians of the Tombs
- An army of golems made in the Precursors' image. Cold, intractable, ancient stone throats repeating warnings in dead languages.
- A silico-organic AI overseeing the entire compound. Vast server banks of bio-geocomputing stromatolites, submerged in warm saltwater.
- Eerily intelligent cats with fur that changes color when slimes are nearby. Unspeaking hunting lodges, claws secreting slime-killing venom.
- Water elementals, bound by ancient pacts to dilute escaping slimes and drown intruders. The corridors have long since eroded into smooth tunnels.
- Sentient utility fog. Swirling, swarming, forming bodies, weapons, false walls. Nanites vibrating unison to speak - an ear-piercing, painful buzz.
- Mummified Precursor liches reduced to the mindless, monomaniacal containment of slimes. Ancient, rotted clothing, still-sharp weapons.
- Pitch-black, towering monoliths. Perfectly smooth, featureless, and cold. They cast off radiation that disintegrates living beings on a molecular level.
- A hermit order of Trilobite-Knights, honorbound to the Precursors' service even after their knowledge of the Precursors faded into mythology.
- The Precursors themselves, lingering as ghosts. They cannot physically interact with anything, but they will horrifically curse any intruder into the Tombs.
- None. The Tombs are unguarded, their safety measures lost to the iron teeth of time. Woe betide us.