For the Dungeons & Dragons 3.5 Forgotten Realms accessory, see Underdark (3.5 accessory).
For the Dungeons & Dragons 4th edition accessory, see Underdark (4e accessory).

The Underdark is a subterranean realm found beneath the surface of most Material Plane worlds. Drow, Duergar, and mind flayers are among the races known to dwell there.

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