Of all the strange places that an adventurer might explore, none is deadlier than the dungeon. These labyrinths, full of deadly traps, hungry monsters. and priceless treasure, test every skill a character possesses. These rules can apply to dungeons of any type, from the wreck of a sunken ship to a vast cave complex.
The four basic dungeon types are defined by their current status. Many dungeons are variations on these basic types or combinations of more than one of them. Sometimes old dungeons are used again and again by different inhabitants for different purposes.