Psion
Adventurer
Pielorinho said:
Thus, dwarves, elves, and dragons aren't a problem. Windy corridors are.
The problem with your assumption is that you assume that someone dug them that way on purpose. I'm no geologist, but I do know that there is a lot of randomness in the way sedimation occurs; lava flows have bubbles in them, diffirent types of earth and rock are easier or harder to excavate or erode. Really, how a person would LIKE the passage to go may be an entirely peripheral consideration.