Inspired by Jeff's Gameblog's list of twenty quick questions for your campaign setting, here are some sets of questions for generating a dungeon of the mythic underworld. Should contribute to generating some find "funhouse" dungeons:
Questions for Generating a Dungeon of the Mythic Underworld
What is the treasure it hides? Is it named? Famous? Backstory? Will any of the above give the characters any clues as to how to find and recover it? How do the characters find out?
Why did chaos want to swallow the treasure in its mythic belly? How did chaos swallow it up? Was it done through chaos’ own occult magics, or were chaotic creatures or characters involved? Has law even become aware? Does neutrality find the capture to bring balance or imbalance to the state of things?
What tricks, monsters and traps did chaos manifest to hold its treasure tight? What wonders, magic-items or clues has law provided as an immune-response to chaos? Are there any pockets of neutral homeostasis, providing brief oases of respite for weary characters?
Is there a single main monster, type or kind? Do the monsters know or understand their role at all? Do they also want the treasure? Do they fear it and would love to rid themselves of it? How can the characters find out?
Is there a single trick or a series of related or random tricks? Are some random tricks simply kooky manifestation of chaos? Does the trick conceal, mislead, harm? Can it reveal, inform or aid if understood and used well? Is the trick a giddy or cruel irruption of chaos? Is the trick actually a miraculous manifestation of an immune-system response from law? Is the trick indifferent to characters, maintaining an odd but neutral balance? What kind of clues are there for the characters to figure these things out?
Are the traps ubiquitous or rare? Obvious or hidden with scattered clues? Have the monsters devised the traps? Or did chaos herself devise them from her own insanities? Has neutrality closed the loop, leaving behind the carnage of those who previously tripped the trap? Has law provided helpful clues and means to disarm the traps?
How many ways in are there? Are there ways in at different levels? How many connections are there between levels? How many open and closed loops of passage does a level have?
How do the characters find out?