Worlds of Design: Making Megadungeons Make Sense

When D&D originally came out Gary Gygax more or less taught GMs that they should make huge multilevel dungeons that the adventuring party would enter and loot, killing the monsters who were guarding it. But in my case we were eager to play, so as GM I made what gradually became a big, sprawling, somewhat random dungeon. And it didn’t always make sense.


Picture courtesy of Pixabay.


My dungeon was only six levels, and the levels were not the vast kinds of things we see in true “Megadungeons” where the graph paper map for one level could be as much as a yard by a yard. Quite apart from the huge question of why does the place exist, we had monsters living adjacent to each other who should be hostile but seemingly didn’t know the others exist, monsters living in places without ventilation, sanitation, or access to food. Inexplicable magics like Gary’s fountain of kobolds (IIRC), a continuous upwelling of kobolds in the middle of a room: where did those kobolds go, let alone where did they come from? One-way doors, secret doors, and rotating rooms placed mostly at random. We didn’t care, it was fantasy, it was a game. And it gave us a sense of wonder or of mystery, a sense of the fantastic.

There was a reason we created dungeons this way. The fundamentally nonsensical dungeon was practical to reduce the work required of a GM. (Keep in mind, there were very few commercial adventure modules at that time, everyone had to make up their own stuff.) I don’t think anyone can argue with that. Gygax's solution to the difficulty of worldbuilding (as paraphrased from Jeffro Johnson, author of Appendix N: The Literary History of Dungeons & Dragons, on Twitter) was to:
  • Have lots of space.
  • Place lairs with vast quantities of loot
  • Use random encounters to simulate an active, dynamic environment with very little effort.
But there’s an entirely different way of making dungeons that makes much more sense, though it takes more time.

Gritty Realism?

When I play RPGs now, I like to feel as though it should make some sense, something like Glenn Cook’s the Black Company, a kind of gritty realism rather than wild (Dunsanian?) fantasy. To me the vast dungeon with unrelated contents and inhabitants, often no way they could even get in and out without running into others, no way to get air, no way to get food, is just plain nonsense. It breaks the immersion in the world that many gamers look for. Worse, there is no explanation for why this vast dungeon exists. I don’t buy for a second the “mad wizard created it” excuse.

So after my initial six level dungeon made primarily for my brother in the Gygaxian Megadungeon style, I kept my underground designs to individual lairs or to Skystone Castle and its environs.

Skystone Castle

Skystone Castle grew out of my thinking about how magic would modify military considerations (keeping in mind I have a PhD in military and diplomatic history, and when I first played D&D I was already two years into graduate school). In an environment where fireballs and lightning bolts are somewhat plentiful, where a charmed umber hulk or burrowing monster can dig underground and undermine any wall, a fortification in a magical world would look more like the World War II Maginot Line than like a medieval castle, with most of the fortifications and living spaces underground. Skystone Castle was an abandoned very large fortification built into an enormous rock that grew out of a featureless plain, and allegedly had fallen from the sky. Such rocks exist (though not from the sky), for example Traprain Law in the UK (though I think of it more as stone than as a hill).

The fortress was long abandoned. Creatures had moved in and made modifications. But I experimented with actually having creatures move in and settle down, as governed to a considerable extent by dice rolls. Sometimes those creatures could burrow or mine-out additional areas, and the map changed accordingly. Sometimes those creatures might live in the dungeon a long time and then someone else would move in and chase them off or slaughter them. Sometimes evidence of inhabitants (and battles) long past would remain behind.

This all made changes in the dungeon. It was like a game in itself, seeing what would happen, and of course I had ideas about what I wanted in the dungeon and that governed who turned up and how strong they were. The result was a “living dungeon” rather than a caricature.

I accepted the notion that the more powerful monsters would tend to want to live deeper, in order to retain the game-practical idea that the deeper you went, the more dangerous it became. Though in smaller such places the danger level was roughly the same regardless of where you were in the “dungeon.”

A Question of Immersion

I still use this method between adventures, so that sometimes when the party comes back to the dungeon it has changed in some ways, if only in the inhabitants, which I think makes for a much more interesting place to adventure in. “Clearing out” a dungeon and never having anyone fill in the space, as in the old Gygaxian dungeons, doesn’t make sense. Yes, it takes more time, but it’s a lot more interesting.

This is not a question of somehow improving sales, it’s a question of improving the immersion that is necessary for most any game. Wild fantasy is one thing; something more realistic, whether it’s the Glenn Cook’s-style of realism or the Tolkien-style of realism, is just as valid a way of playing RPGs in general and Dungeons & Dragons in particular.

My question to readers, then, is what kind of dungeons (if any) do you have in your campaign, and why?

log in or register to remove this ad

Lewis Pulsipher

Lewis Pulsipher

Dragon, White Dwarf, Fiend Folio

Eyes of Nine

Everything's Fine
So first of all, I am reminded of "How to Host a Dungeon" when it comes to generating the history of a dungeon area. Great lonely fun, and result is very similar to what you wrote about.

I am also now desiring a treatise/blog series/mini-book about how society in general and military strategy would change in a pseudo-medieval setting if there was relatively easy access to the magic posited in D&D. If it was done by someone with a PHD in military history or sociology or anthropology, well all the better...

Hmmm, wonder if there's anyone who might have those qualifications...?


My dungeons tend to smaller with only 5-15 rooms and have only a few encounter areas. Most are tombs or natural caves where smaller rooms make for one encounter and monsters join combat each round as they pour out of more rooms. I like to have a set dungeon that I them modify to age them. I recall somewhere where a fissure opened in one of the DM help articles some years ago and I have included that trick a few times. Some others may be an ooze lair having holes in the ceiling/floor to another level where you could bypass the planned stairs. If I needed a massive dungeon I would buy one of the Undermountain or Rappum Amuk (sp) and modify it.


Small God of the Dozens
I tend to smaller dungeons. Something that can make some sense as a unit. You can certainly overdo the history bit, but I do like to include some hints that the location has had other inhabitants and seen use over time. An abandoned observatory in the forest, dilapidated keeps and towers, that sort of thing. Mostly they're done in a session. If I want multiple sessions I'm more likely to spread it over multiple smaller locations than to design something huge.


I think the last mega dungeon I did was when I was a teenager. The hallways of each level spelled a word and, of course the lowest level was the most dangerous.

So the layers in order spelled out "Death", "Doom" and "Destruction". No logic, no reason. Just a bunch of monsters with a dragon on the lowest level and a plaque dedicated to the creator of the dungeon.

I wrote something along the lines of "Uno de podero vivir!" on a 3X5 card. Then I handed the card to the player when they asked what the plaque said. They read it out loud which of course brought the all powerful lich back to life. High school spanish class actually paid off.

I went for the giant megadungeon back in the day. It's still in use :) I did come up with basic reasons for its' existence and I spread it into numerous smaller parts. It's a huge underground fortification (the above ground part is mostly gone) dating from a series of ancient wars. Well stocked with magical affects / defenses, undead, miscellaneous dungeon flora / fauna, and various invaders and adventurers. It consists of dozens of linked dungeons with various themes. I still use the "deeper is deadlier" trope. Some areas are relatively small, others are gigantic. Various parts range from level 1-5 to levels 6-12. Essentially there are watchtowers, barracks, armories, mines, magical workshops, palaces, etc. There are various underground routes connecting it all up; tunnel / foot roads (with gated watch posts along them), "highways" populated by stone golem "trucks", underground canals and rivers, teleportals, magical gates leading to other locations... with the caverns of the Land Beneath the Land Above under that (this being an underground outdoor adventure). There are various vast architectural features / defenses as well. Given the history of the setting it makes reasonable sense. And, it's fun :D

There are, of course, numerous smaller locales scattered around as well that aren't part of a larger whole.

Which sounds a lot like Skystone Castle. In a fit of less than original thought I call mine the Hollow Hills for the ruined above ground remains that resemble a large set of hills.
Last edited:


Never did design a megadungeon. I think my only attempt was a 2-3 level affairs heavily influenced by the caves of chaos with a community of dwarves defending their hard one territory from the various other humanoid communities.

However my own dungeons were always heavily influenced by 2-3 dungeon design/ecology articles Lewis wrote in White Dwarf in the early 80s. I no longer have the mags but the aricles are in one of my early dming folders somewhere.


I generally hew to small to medium sizes, since I fashion my own. I've run official ones, like Ruins of Undermountain (2e), but generally find them unsatisfying (mainly because I can never remember all the details and have to refer to the books often...which tends to derail the momentum my players build exploring). When I create them myself (and keep them small to medium), I tend to remember them in greater detail, which my players have responded very well to. I also try to keep the layout and organization to something sensible (for a constructed dungeon) rather than just randomly populated with nasty things (though for more natural dungeons, like caves and tunnel systems, it tends to be more random, but with occupants that make sense).

Leafing through a friend's copy of Descent into Avernus, I got an idea to do something with Fort Morninglord (going to be known as 'Hellhall' in my game). Basically 10 levels with the above ground level 'safe' but populated with clues and things that brought down the once great fort...with each descending level a sort of a broken off piece of the Nine Hells of the appropriate type (so Avernus, then Dis, then Minauros, etc down to Nessus). Just have the basic concept for now, but plan to flesh it out, add some narrative to my existing game and see how it goes.


Victoria Rules
Probably the biggest dungeon-like complex I've run all the way through is Dark Tower.

I tried running Temple of Elemental Evil once; they cleared the top level and about half the next one, went back to town to train and regroup, and then between one mishap and another never got back to it to finish.

As for my homebrews, I've come up with lots of dungeon-like adventures over the years but most aren't all that big - 20-40 encounter areas, maybe, over two or three levels. I've once or twice kinda waved at doing something much bigger but never really got very far with anything.

I did do one quite gonzo one that was bigger - something like 70-ish encounter areas - where I was very intentionally trying to capture that feel of monsters not belonging where they were (and not being able to fit through the doors) and things generally not making sense: an homage to Judges' Guild's Sword of Hope that I called Shield of Faith (a.k.a. Danger Hill). I'd release it on the unsuspecting world - it's in finished-ish printable form, absent some editing - except it swipes too many identifyable bits of IP from too many other sources and I'd probably never get all the required permissions.

There was even a sort-of rationale for how and why the various monsters came to be where they were and why-how they hadn't yet died of starvation or thirst. :)

My biggest mega dungeon burned if a firehouse. It was the ruins of an ancient city that was built upon an even more ancient city which was built upon... well you get the picture. Most encounters in the begining levels were with humanoids, traps, hazards and a few undead here and there. Then there was thematic and semi-thematic levels. One would be with a wizard and its minions, and other was a dragon trapped in there because greed kept him in the dungeon (players had had encounters with the dragon's minions carrying dirt and soil to the surface because the dragon was making them dig for the surface). Even then, I was 13 and I was trying to bring some logic. The deepest dungeons were filled with undead, constructs and outer planar creatures.

But my best mega dungeon, which burned too, was the Labyrinth. It was set in a city, and it was a contest. Each year, 4 groups were to enter the labyrinth, fight each other and the menaces that could be found in it, to bring back the Orb of the Vanquishers! The prize? A wish for all party members that survived. Those who died or failed to come back before the 7 days period, were raised from the dead and were forced to serve the Archmage Ozzymandius for five years. Sometimes it meant geas and quests for the Archmage, other times it meant being a foe for the contestant in the labyrinth. It was a dungeon with 12 levels and the few groups that tried it found it challenging and fun. God I wish this fire didn't happened.

Latest threads


Upcoming Releases