Extending miles downward and outward beneath the surface of Minnoa, the great network of subterranean caverns known as the Underdark is home to all manner of strange and deadly creatures. Duergar and drow — dark reflections of dwarves and elves — live in these sunless lands, as do the svirfneblin, or deep gnomes. Most surface-dwelling folk aren’t threatened or even disturbed by denizens of the deep places, but the creatures occasionally emerge to raid or to seek some kind of goal in the surface world.