The Dungeons of Doom

This is a downward-extending branch consisting of between 25 and 29 levels; it is the branch in which the player begins the game.

The following dungeon branches connect to the Dungeons of Doom:

Elemental Planes(DL 1)
Gnomish Mines(DL 2 to DL 4)
Sokoban(DL 6 to DL 10)
The Quest(DL 11 to DL 16)
Fort Ludios (DL 11 to DL 27, not guaranteed)
Gehennom(DL 25 to DL 29)

The following special levels may be found in this branch:

Top Level(DL 1)
Oracle(DL 5 to DL 9)
Big Room (DL 10 to DL 12, 40% chance)
Rogue Level(DL 15 to DL 18)
Medusa's Island (2nd to 5th level from bottom, DL 21 to DL 28)
The Castle (Bottom level, DL 25 to DL 29)

(Note that some level ranges are interdependent, so certain combinations of branch/level locations are impossible; for more specific information, see individual entries.)

Most non-special levels consist of an "ordinary" room-and-corridor layout; some rooms may be special (see room-343.txt). Levels between Medusa's island and the Castle have a 4/5 chance of being mazes. All non-special, non-branching levels below DL 3 are eligible to leave bones files (which may result in maze levels being encountered outside the range just noted).

NetHack 3.4 Spoilers
Dylan O'Donnell (