A megadungeon, mega-dungeon or superdungeon is a large, sprawling dungeon complex. A megadungeon may form the basis of an entire Dungeons & Dragons campaign.

The term "megadungeon" is widely known in the Dungeons & Dragons community, but has historically been rarely used in Dungeons & Dragons products. However, the concept of a megadungeon dates back to the original edition of Dungeons & Dragons, with The Underworld & Wilderness Adventures (1974) describing vast multi-layer dungeons as the primary location in which the game takes place.


A megadungeon is a massive dungeon consisting of multiple separate layers. Megadungeons typically have long and complex histories, with different levels constructed in different eras by different groups of people. Such a dungeon naturally develops an elaborate system of interconnected ecologies.[1]

Unlike a standard dungeon, where it is plausible for an adventuring party to kill all monsters and recover all treasure, a megadungeon is so huge as to make this impossible. The size of the dungeon is so great that even if adventurers clear out a large section, it will be populated by new inhabitants before they can finish clearing out another. Megadungeons are commonly deadly.[1]


Adventures described as megadungeons or superdungeons, or which meet its description, include:

In third-party D&D products, AEG's 2004 product World's Largest Dungeon is notable as a megadungeon of incredible size and scope, taking player characters from level 1 to 20 and containing every single monster in the D&D third edition SRD.


The terms "megadungeon" and "superdungeon" have been used only infrequently in official D&D products.

Dragon #166 (Feb 1991), p.25, in a listing of new products available in March, describes the Forgotten Realms boxed set Ruins of Undermountain{{UnknownBook}} as a "super-dungeon", and the "ultimate dungeon crawl". It describes the product as a return to a more old-school fashion of D&D adventure. Also set in the Forgotten Realms is Ruins of Myth Drannor{{UnknownBook}}, described in an advertisement in Dungeon #41 (May/Jun 1993), p.77 as a "super dungeon".

TSR's 1993 catalog describes ALQ2 Assassin Mountain (1993) as a "super dungeon" setting similar to Ruins of Undermountain. Land of Fate (1992), another Al-Qadim sourcebook, notes on page 39 the lack of any "super-dungeon" in the city of Qadib.

In the Polyhedron #144 (Oct 2000) article Ecology of a Dungeon, Matthew Hancock describes "so-called superdungeons", also called "mega-dungeons". The issue also describes a "Mega Dungeon" created by Mark Smith, run over four days at Gen Con UK 2000.

In The Plane Above (2010), p.12, the realm of Tytherion is described as a sort of megadungeon. In Dragon #389 (Jul 2010), p.84, the Abyss is described as a mega-dungeon.

Reception and influence

The concept of a single massive dungeon complex as a setting appears in many D&D-inspired video games, including NetHack and Torchlight.


  1. 1.0 1.1 1.2 1.3 Ecology of a Dungeon, Polyhedron #144, p.34.
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