The Unidoom DM series is an ongoing series of deathmatch WADs created by Clan Unidoom in 2002. They are regularly played in ZDaemon's deathmatch tournaments and were frequently played on Skulltag's Friday Night Fragfest, and have been a significant source of inspiration and influence for deathmatch mappers in both the ZDaemon and Skulltag communities.
UDM1 was released on January 1st, 2002. Containing sixteen deathmatch maps, two deathtag maps, and two parody maps, it became an instant hit in the deathmatch community. Notable DM mappers such as TLSDM's ChronoHunter have cited UDM1 as the source of their inspiration to map.
UDM2 development started shortly after the release of UDM1, but lack of motivation slowed progress down to a near-halt in 2002. However, development soon resumed and UDM2 was eventually completed and released on March 2nd, 2003. It was initially rejected from /idgames (see Controversy). It contains twelve deathmatch maps, a parody map, and a credits map. Like its predecessor, UDM2 mostly consists of maps authored by Ralphis and deathz0r.
UDM2 notably features a map that is a tribute to the video game Super Mario Bros. 3, some of whose graphics are used as sprites and textures in the map.
The second sequel to UDM1 was released on December 25th, 2004. Unlike its predecessors, UDM3 was created by a score of current and former members of Unidoom and contains few custom textures, which upped the file sizes of its predecessors. UDM3 contains sixteen deathmatch maps, two parody maps, and a credits map; it also features a new palette that modifies greens and blues to produce a new look and is one of the WAD's hallmarks.
UDM3's standout map is Citadel of Unidoom (MAP16), which was an attempt by deathz0r to have as many Unidoom members as possible cooperate in the creation of a single city containing their own buildings. Although the layout was not completed due to lack of time, it is a playable, detailed map designed for free-for-all gameplay.
After undergoing several years of sporadic and aimless work followed by an entire year devoted to its renewal and completion, the fourth installment of the series was released on December 31st, 2008. UDMX is the first entry in the series to fully replace Doom II's original 32 levels, several of which are replaced by remakes ("flashbacks" as called throughout the WAD) of maps found in UDMX's predecessors. Unlike UDM3, the WAD uses a rich variety of custom textures and boasts a new palette that saturates reds and greens and deepens blues. While under development, the project underwent a series of name changes: initially called what it is now, it was eventually renamed "UDML" (Unidoom DM Legends), then briefly "UDMC" (Unidoom DM Classic), and lastly UDM4; however, it was soon decided that it would return to its original title. UDMX celebrates Unidoom's 10th anniversary, bearing the "X" in its name to represent the ten years that had passed since the original 1998 founding of Unidoom at the time of the WAD's release. At a whopping 20.7 megabytes, UDMX is the largest UDM installment by file size. UDMX has received much critical acclaim throughout the community, deemed by reviewers as the best installment of the UDM series and one of the greatest deathmatch megawads to have ever been made.
Two issues have been raised about UDM1: the use of Skulltag textures without the permission of Carnevil and the plagiarism of MAP06, although the latter was not known until it was revealed by deathz0r a few years following the WAD's release.
Similarly, UDM2 used Skulltag textures without the permission of Carnevil. In response to UDM2 being uploaded to /idgames, Carnevil sent an email to Ty Halderman, the archive maintainer, requesting it to be removed from the server. This action sparked a debate in the Skulltag IRC channel, after which Carnevil eventually agreed to allow the Unidoom clan to re-upload UDM2.