Caverns of Darkness

Caverns of Darkness is a 12 level PWAD for Doom II created by The Chaos Crew and released on April 24, 2002. It is packaged with a required custom source port executable for, a fork of the Eternity Engine dubbed "EE 3.29 dev beta 5 joel-2". The levels are well-known for their use of voodoo doll conveyor belt scripting, ambient sounds, and fake 3D (through middle textures) to create more realistic subterranean environments.

Authors
Levels for the WAD were made by:


 * Christopher Lutz
 * Pedro Francisco Puicón (NokturnuS)
 * Emil Brundage (NaturalTvventy)

Programming for the engine was done by:


 * Joel Murdoch

Music for the WAD was written by:


 * Justus Johnson

Levels
All levels by Christopher Lutz unless noted otherwise.


 * (exit to MAP11)
 * by NokturnuS
 * by Emil Brundage (exit to MAP12)
 * by NokturnuS
 * (secret map)
 * (secret map)
 * by NokturnuS
 * (secret map)
 * (secret map)
 * (secret map)
 * (secret map)
 * (secret map)

Soundtrack
Aside from one custom track, all levels use Doom and Doom II songs by Robert Prince.


 * MAP01: ? by Justus Johnson
 * MAP02: "Running From Evil" (from MAP01: Entryway)
 * MAP03: "The Demons from Adrian's Pen" (from E2M2: Containment Area)
 * MAP04: "The Demon's Dead" (from MAP10: Refueling Base)
 * MAP05: "Donna to the Rescue" (from E3M2: Slough of Despair)
 * MAP06: "Waiting for Romero to Play" (from MAP18: The Courtyard)
 * MAP07: "Waltz of the Demons" (from E2M7: Spawning Vats)
 * MAP08: "Into Sandy's City" (from MAP09: The Pit)
 * MAP09: "Shawn's got the Shotgun" (from MAP07: Dead Simple)
 * MAP10: "Getting too Tense" (from MAP28: The Spirit World)
 * MAP11: "They're Going to Get You" (from E2M4: Deimos Lab)
 * MAP12: "They're Going to Get You" (from E2M4: Deimos Lab)
 * Title: ?

Caverns of Darkness Engine
Caverns of Darkness Engine (or CoD Engine) is a source modification created by Joel Murdoch and based on Eternity Engine v3.29. The file included in the PWAD's archive is a source modification compiled for MS-DOS. To play Caverns of Darkness in, a DOS emulator such as must be used. The binary adds more level editing features including:


 * a new instant-death sector type for players falling into a black void
 * a healing sector type that gives players health
 * two new lighting effects to adjust sector brightness by 15
 * looping ambient sounds
 * additional attacks for the Archvile and Cyberdemon

On May 4, 2002, The Chaos Crew member Christopher Lutz published Joel's source code to the team's web site. However with the file stored on Joel's personal hosting, the link eventually went dead and the source became unavailable for more than a decade. On May 26, 2019 Joel Murdoch re-uploaded the source and posted a new download link to the Doomworld forums. It was made available on the idgames archive on January 31, 2020.

A new source port, Tartar, was released in December 2021 based on the CoD Engine source code and integrating various other improvements.

ZDoom version
On January 23, 2005, Graf Zahl supplied a source modification called, derived from ZDoom 2.0.96 that made the necessary additions to play Caverns of Darkness. It reports in-game as ZDoom 2.0.96c (COD custom). On November 15, 2008, he released a CoD PWAD patch to instead allow the levels to be played using the regular ZDoom build. It substitutes DECORATE actors in place of the original hard-coded custom thing types and weapons, as well as using MAPINFO to apply map translators that replace the CoD engine's new sector and linedef types.