Ragnardbard inspired this post, via his beautiful maps for the "storeroom" DIY level of the Vault of the Mad Archmage. One thing leapt out to me immediately: the tightly-packed nature of sections of the dungeon level. I liked it, but I realized immediately I would never have drawn it that way because of my own preferences and biases.
For you see, to my dungeon engineer's eye, you've got to have Space Between!
Compare, for instance, these two classic D&D maps:
Quasequeton is packed. The Tower of Zenopus (as the Homes D&D dungeon has been called) is sparse. I fall somewhere in the middle here, with an acknowledged preference towards having some space between rooms, usually 10' worth.
I find it amusing that I care about such things in a fantasy world that is home to monstrous levitating meatballs with eye stalks, but I imagine somehow that without such a rock buffer my dungeon would structurally fail. This would seem to be more true the deeper one goes -- more support needed for all that rock-weight above. Thus, I look at Quasequeton and see a proverbial house of cards, albeit one with some magic pools on the seven of hearts.
But then I eye Zenopus' abode and say, "my, that's an awful lot of wasted space. That seems less functional." Without a design goal (like, say, to reach the underground river in area M), why tunnel when you don't have to? Couldn't all of rooms A - J been put closer together and achieved the same functionality?
Here's something more up my alley, though it's certainly more Zenopusian than in my preferred middle ground:
The Moathouse dungeon works for me despite its relative sparseness -- though I think Gygax could have fit several more rooms in here easily without having the Moathouse crater upon itself. Gygax's own above-ground structures were more packed (needing less support) while his caverns and dungeons had Space Between to one degree or another.
Torn between realism and functionalism, and asking myself WWGD, I have suconsciously decreed that a 10' minimum Space Between has become my default for underground designs. Armed with this, I can effectively suspend disbelief and maintain functionality and design flow.
I just have to catch myself to not do this above-ground, though. 10' spaces between everything is not functional in a building, unless we are discussing exterior castle walls.
I think I need to go out and draw a dozen outdoor hedge mazes now to break myself of this. Ah, the little internal boxes we make for ourselves, eh?