Many of us know the joy of describing a complex dungeon and watching our friends studiously attempt to chart it out on graph paper, in many cases distorted by the “picture-telephone effect.”  And mapping out a dungeon can be serious fun for a DM.  But sometimes, adventurers want to explore a place which should, by rights, be so tremendously complicated as to be un-fun to map out.

Consider the maze of sewers under a major city.  They’re a perfect dungeon in theory, but in practice they’re literally miles of sprawling tunnels that pass over and under each other vertically.  The same goes for catacombs, labyrinth dimensions, non-Euclidean Lovecraft ruins, haunted forests, and psychic purgatories (made of halls full of doors with, presumably, live-action train footage on the other side).  All of these places are too vast and too maddeningly complicated for a team of adventurers to explore them in their…