Splitting off from the "When should the GM play fair?" thread, one point about what made "fairness" in an old-school dungeon crawl was that players could, in principle, ensure they never got in over their heads by sticking only to the upper levels of the dungeon and to monsters/opponents and challenges that matched their own ability, waiting to tackle deeper levels and more powerful foes until they'd gotten more powerful themselves. The thought that immediately came to my mind was, "Sure, but that's just an artifact of when dungeons were designed for game expeditions; there's no guarantee that a 'real' dungeon would be so neatly organized. In fact, most 'dungeons' don't really make much sense at all except as carefully organized target/reward structures for dungeoncrawler PCs."

However, since I always believe there are exceptions to any generality (and the exceptions are usually the most interesting examples), I wanted to ask what dungeons people have seen that actually did "make sense", in terms of why they were where they were, why they were laid out as they were, why their occupants were who they were, and why the internal challenge progression made sense. Or if anybody had designed one for their own game that they were particularly proud of in this manner.

To start the ball rolling with my own example, I have to admit that I was always a big fan of the old AD&D1E module The Forgotten Temple of Tharizdun. This really is an example of a setting where players can start with low- to medium-difficulty challenges and then really face more dangerous ones as they probe further and further into the temple and the dungeons beneath, and it all makes sense why everything is where it is and the order in which it's discovered.

Tomb of Horrors. Once you realize its a huge intelligence test it makes a-lot more sense. And it gets harder the further you get. But it is also a completely unforgiving dungeon.

While not a dungeon. I1: Dwellers in the Forbidden City was pretty good for a city crawler.
The Lost City is another that its theme makes sense in its weird way.

Mythic underworld? Living dungeons?

Anomalous Subsurface Environment. Simultaneously one of the most gonzo as well as one of the most well-thought-out dungeons (and settings).

I wrote a module with that in mind, since I dislike nonsense dungeons with kobolds, skeletons, and giant beasts in succession for no reason.

Basically, hex-shaped rooms created by a bee-avatar gone crazy. Each part of the dungeon is ruled by a different faction or theme. The demons have arenas, a mess hall, prison, etc., while the bees basically protect the queen avatar and create more bees. The ruins of the old temple is full of debris, statues, etc. Sentry are located in important junctions and key areas. Traps are made for one faction against the other.

You can find the map and the one-page version here:

https://methodsetmadness.blogspot.com/2015/05/the-wretched-hive-my-one-page-dungeon.html

In the real world in which we live, entire inhabitable cities have been carved out of the rock layers underground.  I know of at least one, which would have sheltered tens of thousands of people.  I watched a video tour of it, on YT; but I can't remember the name of the city.  Nobody knows who built it, or why it was built.

Then you have naturally occurring underground cave structures, manmade catacombs, etc.  There are many examples of underground "dungeons" waiting to be explored, in the world in which we live.  I think having a dungeon which has a reason for existing, adds to the logical immersion into the game setting.

I'll grab the lowest hanging fruit:  Moria.  The dwarves built a city and mines then encountered more than they could handle.  The monsters lived deep and once they had eradicated the dwarves, had little reason to come upstairs.  So you have mostly empty upper levels with (probably, we didn't see any) just a few enemies of the type that move into abandoned places.  You don't encounter serious opposition unless you go deep or start dropping stuff down wells.

I'll add that none of my adventure are ever random monsters in rooms.  Step 1 is "Why was this place built?"  Step 2 is "How is the location being used now?"  And step 3 is filling in encounters that make sense in light of step 1 and step 2.  This doesn't always lead to progressive difficulty, but it does often lead to clues about difficulty.  In one dunegeon a goblin tribe had barricaded off a section of caves where there were some really dangerous unintelligent monsters.  The party took the hint and didn't go that way.  (It wasn't relevant to their goal anyway)  IIRC, it was a 25' long basilisk type creature whose gaze turned enemies into ice rather than stone.

I'll often start with a logical structure then age it in ways that make sense for the gaming aspect. 

For example, I prefer multiple entrances, loops, and so on, typical of some of the more interesting gaming dungeons.  I also like to include plenty of vertical elements, both to add other loops, provide more tactical opportunities, and reward players that think in 3 dimensions.

In a dungeon I'm running right now, it starts as a fairly standard keep, with a modest set of storage, dungeon, etc. rooms underneath.  Nothing special.  Then I added 3 separate secret escape tunnels on the grounds that the original inhabitants were paranoid.  Next, it's got at least three other entrances due to cave ins, giant insect activity, and the machinations of a ghost.  Two towers are partially caved in.  A section of the underground ruins is completely collapsed, with a door surrounded by rubble that leads nowhere.  Three different intelligent factions have a place there, with two grudgingly cooperating, and the third motivated by aggressive desires to capture sacrifices.  They've all done their own thing in the areas they control to change the layout.  Thus there is a mix of old, rotted, hidden, repaired, crude new stuff, and some more elaborate or savvy new things as well.  It starts as a logical keep, mostly boring.  It ages into something more interesting.

It looks on the surface like a fun house dungeon.  And yes, I kind of made it drift that way on purpose.  But everything in it has a logical reason that is not only consist within itself but also says something about the nature of the setting, both currently and its history.  Now, I do like to add fantastical elements with a sense of fairy tales, because that's the kind of setting that I run.  However, those are also chosen to stand out, and to fit that role, in an otherwise fantasy naturalistic setting.

I think the most logical dungeons are the fortress type, where all (or almost all) of the opposition are related to a single premise. Something like G1 Steading of the Hill Giant Chief, though even that has some odd encounters that seem disconnected from its use as a fortress (like the troglodytes and carrion crawlers). I'd say I6 Ravenloft also works that way, in that almost everything relates to the master vampire Strahd.

The most common ways that a dungeon isn't logical is how it stocked with dangerous monsters clustered around a particular difficulty. A lot of dungeons have largely unrelated monsters that just show up. For example, there are a group of troglodytes in the original G1 that have no reason to be there.

Using the idea of the Mythic Underworld, I think a lot of "illogical" dungeons can be explained in that it's a meeting point between good and evil. Like the Girdle of Melian in Middle Earth.

"Beyond lay the wilderness of Dungortheb, where the sorcery of Sauron and the power of Melian came together, and horror and madness walked."

I've often thought that a good ending for a megadungeon is to find some kind of thing on the bottom level that causes all the madness of the upper levels. Like a corrupted artifact or an imprisoned god. Powerful enough to warp it's environment, but not powerful enough to just outright kill anyone entering.

Quote from: Ratman_tf on December 14, 2022, 05:35:42 AMI've often thought that a good ending for a megadungeon is to find some kind of thing on the bottom level that causes all the madness of the upper levels. Like a corrupted artifact or an imprisoned god. Powerful enough to warp it's environment, but not powerful enough to just outright kill anyone entering.

That's pretty much the conceit behind Stonehell.

+++ SPOILER +++
The entity both feeds on and encourages the chaos, as well as actively drawing in more victims from the outside.

We never ran underground mazes full of traps, and a treasure chest guarded by a boss at the end.  It's too contrived. 

Our usual setup was a bandit base built by lazy people, so it's maze-ish.  The other setup was abandoned ruins full of monsters too dumb to know they're sitting on valuable gear. 

For an example, a temple to the god of animals had an icon on its alter built into a small canyon that's been roofed over.  The problem is the icon made the animals giagantic and aggressive, so nobody lives there.  Our job was to fight our way into the place, and smash the icon to return the area to normal.  It wasn't a complex setup.  More like a linear set of 5 rooms. 

Those gigantic man made tombs are the exception. 

My "dungeons" are always places that are forgotten/unknown where the inhabitants are effectively living in their ecological niche.

An example, and mind you this might be silly sounding, it was intended as such on the surface. I had a Dwarven Forge asteroid discovered by my PC's, and it was abandoned (to their excitement). But the massive fortress was sectioned off by the creatures living there. In one section, Space Hamsters had devolved into sabre-toothed cannibal stealth killers, predating upon different colonies that had budded off centuries ago. Another section was infested with Yitsan (think Alien) which predated upon the Space Hamsters, and predating upon all of them were low-end demons, which were able to come through an open portal at specific time junctures (which is what killed all the dwarves in the first place - the Space Hamsters were their pets centuries ago).

The PC's would dungeoncrawl exploring what they assumed would be their new base of operations... only to find clues in various places as to what happened. So Mines of Moria meets Spacehulk.

In other places I'd create secret labyrinthine labs where Sorcerers of Old(tm) were performing experiments on the first "aberrances", after all these monsters came from somewhere.

Or they're ruins that monsters/creatures/people came to set up shop, because they could. I rarely have old-school dungeons where rando-monsters live eternally in the room next-door to other monsters without any context.

There's always the magical menagerie idea - where I had players find these ancient ruins of literally almost every monster in D&D (circa 2e) in stasis... where the ancient elven rangers had hunted them down and caught them and rather than kill them put them in stasis. Most of the dungeon-diving was actually avoiding and bypassing mechanical traps, until they got to the central part of the massive secret base where this huge magical gem was ensconced in this dais... of course this is what powered the stasis fields, and of course it was worth thousands of gold (and I tend to have a silver-based economy) so my players had to have it. And then they popped it out... the magical lights went out... then I'd like to believe as I described it they heard something like THIS... oh and it was *on*.

Natural caverns require their own ecological logic. So I always start at the bottom and work my way up to the apex-predator(s). When I did all the monsters for Talislanta The Savage Land, I had to really think it all out, which is why there are so many nasty beasts in there vs. "normal" monsters, because frankly in a post-apocalyptic fantasy, given the flora and fauna and general desperation of things , the fastest adapting and most fecund creatures would be pretty ubiquitous barring special environmental issues, while apex predators would be either the most highly adapted, and or range-limited, environmentally restricted creatures. Which of course are the most interesting things to fight... and become terrified of.

Can't remember the exact reference but somewhere in AD&D1E or B/X there was a mention of abandoned wizards' towers still stocked with their former owners' collections of henchbeings and experimental subjects. Logic would probably require the stocking to reflect a brutal Darwinian sorting-out of the denizens after the original owner vacated the premises. You could have the orc henchmen near the entrance and then the deeper crypts where they don't go.

There is an Alastair Reynolds SF story about rich sickoes who compete to stock collections of rare and dangerous creatures. A fantasy environment could easily have similar. It's just a variant on the abandoned-wizard's-tower theme.

Back in the real world, Silk Road explorers like Aurel Stein were sticking their noses into cave tomb complexes within the last 100 years or so.