Forgotten Realms Wiki
Forgotten Realms Wiki

The Ruins of Undermountain is a boxed set written by Ed Greenwood and released by TSR in 1991. The material describes Undermountain, the infamous über-dungeon of the Forgotten Realms. It is the first in what became a series of supplements about Undermountain.[1]


UNDERMOUNTAIN awaits you: the fabled and feared battleground of the Realms—"The Deepest Dungeon of them all."

DARE YOU FACE ... miles upon miles of deadly traps, glittering treasures, strange and cryptic rooms, and slithering, skulking, lurking monsters? They await you underneath Waterdeep!

UNDERMOUNTAIN is a dungeon setting for AD&D® 2nd Edition campaign play: the oldest, largest, and deadliest dungeon-crawl in the FORGOTTEN REALMS™ Campaign Setting. It is the place where intrepid adventurers endeavor to become veterans, to win a place among the rich and famous—if they survive its depths. Enter an endless maze where waiting death bears a thousand faces and treasures lie hidden in a thousand places.

It's just the setting for long-running, memorable, great AD&D game play, the perfect locale you'll never forget. So please, come in. Mind your step among the skulls. Oh, yes—good luck—you'll be needing it.

The RUINS OF UNDERMOUNTAIN Campaign Set includes:

  • A 128-page book describing Undermountain, its history, its horrors, and details of the first three levels of the dungeon;
  • A 32-page adventure book for use exclusively with Undermountain and Waterdeep;
  • Four full-color maps of the vast and dangerous dungeon;
  • Eight Monstrous Compendium pages of new monsters; and
  • Eight durable cards loaded with traps, treasures, and trinkets to fill your dungeons.



baneguardbatbrown moldbugbearcarrion crawlerchimeraclay golemcrawling clawdrowdung snakeettercapgargoyleghastghoulgiant centipedegiant weaselgiant gargiant spidergnollgoblingrellguardian skeletonhelmed horrorhobgoblinkoboldleucrottalurker abovemimicnecrophidiusneo-otyughochre jellyorcpeltastratroperrot grubsalamandersnakespectrespider, flyingstirgestone golemtentamorttrappervampyrewater weirdwereboarwyvern


blast scepterbracers of defensebrooch of shieldingglim-gauntletgreenstone amulethorned ringiron bands of Bilarromedallion of ESPring of fire resistancering of mind shieldingring of protectionring of the ramring of regenerationring of spell turningrod of absorptionstun spherevorpalwand of paralyzationwhip of withering


Food & Drink



  • This adventure was ranked the 17th greatest adventure of all time by Dungeon magazine for the 30th anniversary of the Dungeons & Dragons® game in 2004.[4]


  1. This is derived from the date given in Cloak & Dagger for the death of Flaern Cragsmere, mentioned in the Undermountain Adventures booklet in this boxed set.


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Ed Greenwood (1991). “Campaign Guide to Undermountain”. In Steven E. Schend ed. The Ruins of Undermountain (TSR, Inc.), p. 2. ISBN 1-5607-6061-3.
  2. Steven E. Schend, Sean K. Reynolds and Eric L. Boyd (June 2000). Cloak & Dagger. (Wizards of the Coast), p. 99. ISBN 0-7869-1627-3.
  3. Ed Greenwood (1991). “Undermountain Adventures”. In Steven E. Schend ed. The Ruins of Undermountain (TSR, Inc.), p. 19. ISBN 1-5607-6061-3.
  4. Erik Mona, James Jacobs and the Dungeon Design Panel (November 2004). “The 30 Greatest D&D Adventures of All Time”. In James Jacobs ed. Dungeon #116 (Paizo Publishing, LLC), pp. 68–81.