The Megadungeon in its Natural Habitat

In response to my previous post about the possibilities of the avaricious taking advantage of the existence of a traditional megadungeon, someone wrote:

…stuff comes OUT of wild dungeons, right? To, you know, feed on stuff, like merchants stupid enough to be hanging out too close.

And I thought it was an interesting enough question to bring it into the light of day and answer it as a post of its own.

The short answer is, no. The only things that come out of megadungeons (such as Castle Greyhawk, Maure Castle, Castle Blackmoor, etc.) are treasure and adventurers, some of the latter on their shields rather than holding them.

The reasons for this are manifold. The geography of the megadungeon is definitely a factor against it. Most traditional megadungeons have choke-points in the dungeon itself that serve to restrict movement from level to level (or, alternatively, region to region). In most cases, these are stairs. There are just so many staircases that lead from one level to another, and in many cases there’s only a single staircase that even breaches the surface. (Castle of the Mad Archmage, I should point out, has a number of such entrances, including some that lead directly to some of the deeper levels of the dungeons, as did Castle Greyhawk which inspired it; but the principle holds, as those are still limited in number.) Those trolls on level 10 of the dungeon just aren’t going to spend hours schlepping up through the upper nine levels to get to the surface. What would be their motivation? Food? Loot? If that was what they were looking for, they wouldn’t have put their lair 200′ below the surface of the earth, with hundreds of traps, tricks, portals, and other monsters between them and daylight. Those dungeon denizens are there to stay.

Too, it should be remembered that, not only is the megadungeon a “mythic underworld” in the classic sense, but it is also, for the most part, a closed ecosystem, fed occasionally by protein from adventuring parties and the odd influx of gold from insane wizards. That’s Gygaxian naturalism at its best; while it may not work out entirely square in terms of the ratio of large carnivores to herbivores, at least there is usually an attempt to have sources of water, lichen eaten by vermin eaten by small things eaten by big things, etc. The large nasties that would rampage across the countryside simply have no incentive to do so. They made their lair in that maze because there was an ample supply of giant rats, not because of its proximity to deer (or humans) on the surface.

Note that this is all said in relation to the megadungeon. A smaller dungeon, or a monster lair, is a different thing entirely. In those environments, most of the time the big nasties are going to come out, if for no other reason than it’s easy to do so and the underground isn’t large enough to support enough giant rats and centipedes to sustain a clan of ogres and trolls.

So the environment around a megadungeon is probably going to be relatively safe. Getting out is relatively difficult (just as difficult as getting in), and a megadungeon by definition is going to be large enough to be able to sustain the creatures within without forcing them outside for food. Creature lairs and small ten-room dungeons are a very different story, but nobody is talking about setting up an inn outside the entrance to a lost demon shrine. Those cultists are lousy tippers anyway.

Written by 

Wargamer and RPG'er since the 1970's, author of Adventures Dark and Deep, Castle of the Mad Archmage, and other things, and proprietor of the Greyhawk Grognard blog.

7 thoughts on “The Megadungeon in its Natural Habitat

  1. Interesting point, I never really thought about it this way. I have no idea what happened in the classic campaigns, I am not a scholar of those games. Oddly, in my Stonehell game this happened last session. The hobogoblins from level two raided the players' hometown. Of course in Stonehell the hobogoblins are more like the adventurers than they are like the natives of the megadungeon, they are using it as a base to start their domination of the region.

    I loved your last megadungeon post too, I am now planning to have a dragon slayer for hire show up in town. There is a dragon that the party knows about, but has been cleverly avoiding.

  2. I think it really does depend on the megadungeon in question. For example, the neighborhood megadungeon for us has hundreds of entrances and spews forth flocks of harpies, packs of wargs, etc., etc.

  3. Great explanation. The logic of the mythic megadungeon is new to me, and you just made it make a whole lot of sense. Self-contained ecosystem is a great way to think of it.

  4. After one hunderd and eleven years the great bronze doors in the mountain have opened again.

    The village has been there for three generations, founded by traders and travelers cautiously advancing into this rich valley of timber, black soil and silver nuggets, after a time of unbelievable whispers of doom. Ruined towns and castles along the valley speak to a longer history.

    In the crypt of one ruin's chapel, a diary tells what happened a hundred and twelve years ago. The doors opened; some yokels and chancers went in, never again to be seen. A posted guard and quickly built palisade reassured almost everyone. Until, ten months later, the great bell sounded from deep inside the mountain.

    The first week they fought orcs and goblins from the first level.

    The second week, the gnolls and ghouls of the second had their way.

    The third week, ogres and worse things overran what resistance was left.

    The weeks ran on in a living hell until a figure with wings of night flew high and blotted out the sun, calling the horrors back to their deeps. And the doors clanged shut.

    How long until the bell sounds this time?

  5. Interesting thoughts in these two posts, but if your megadungeon is part of the mythic underworld it seems reasonable that NPCs will treat it that way… they being the normalcy whose night terrors inform the myth. Hardly stock in which to find Purple Worm Tamers.

    Now, your garden variety wahoo Greyrealms or Forgottenhawk Megadungeon – yes, that doubtless has Petrification Insurance Salespeople and pre-adolescent fanclubs centered on famous wizards and all that.

  6. As the megadungeon exists in the world in most cases (barring use of extradimensional construction) there has to be some interaction unless you put one or more obstacles in the way to stop this kind of interaction like Tolkien did with Moria.

    Also NPCs intent on exploiting the megadungeon may find resistance in NPCs who protect it like Arha of the Tombs of Atuan (well OK she's ultimately a bad example but…)

    I've always thought megadungeons should impact local ecologies, the banshee's wails killing gentle plant life and leaving nettles and thistles to blossom for example – having the local megadungeon be the main source of drinkable water makes a different dynamic too.

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