Canon would refer to the body of works related to a particular subject and considered proper history and continuity to series. The Doom series may contain more than one canon based on storylines of various reboot universes.

See also Timeline.

Background

In case of Doom there are very few official comments that relate to canon or discuss canon directly. Sometimes official positions are contradictory or changes over time (or retcons are made).

As such there are a number of fan theories as to what comprises canon or what is not canon these can only be considered Fanon as there is very little as far as confirmation on what is canon.

In addition the Doom series has received a number of spinoffs and reboots throughout its life as well as tie ins.

Each reboot could be considered separate canons or alternate universes as part of a multiverse (Quake Arena backstory for example, Arena Eternal outside time and space, with heroes from various "alternate universes").

Tom Hall and John Romero have confirmed that several ID series are in fact connected. Doom Marine (from Doom/Ultimate Doom) is a Blazkowicz descended from Commander Keen, and William J. Blazkowicz before him^[1] (this does not apply to the MachineGames reboot universe however which follows its own universe with an alternate history for B.J. and a different family tree, and its own alternate Keen family as part of the ID multiverse). This is also mentioned in Wolfenstein/Doom RPG series as well. See ID multiverse timeline.

In both Doom RPG website and Doom 3 boxset the hero for most of the games is alluded to be the same hero in Doom 1-3 (and the RPG series). However, the exact order of the series is not entirely clear. With some interpretations placing Doom 3 as a sequel after first two games, and others as a prequel. A number of sources would support the idea that original Doom series takes place almost a century before Doom 3.

However Doom II's marine may or may not be the same character or a separate character from the Doom I character depending on different manuals and websites. His backstory differs from that of the original Doom character in that he fought on UAC Mars Base and escaped in a drop ship (mirroring events of Doom 3). Whereas as original Doom character fought in Phobos and Mars and in both original Doom and Ultimate Doom reaches earth via transporter gateways. Both Doom RPG website and Doom 3 BFG Edition try to establish that its the same Marine in all the games (however this would ignore certain details from other manuals or the games themselves, or at least make things in the timeline far more convoluted, or at least in an unknown order). Doom 3 BFG Edition's manual also goes as far to include Lost Mission and Resurrection of Evil in that claim (which is unlikely considering that in-game clearly indicates they are seperate Marines with different ID numbers, and in case of Doom 3 and Lost Episodes occur concurrently with each other).

Quake Champions brings back Doom (Quake III Arena), now listed as Doom Slayer, and mentions his pet Daisy confirming a link between Doom 2016 and Doom 1. Doom Slayer also comes with his uniforms from Doom 2016 (Praetor Suit), Doom Classic (Doomguy), Quake Arena (Arena), and Doom 3 (Doom Marine), and biography details that links all the games together.

The game also brings new MachineGames William Blazkowicz from his "universe" to the Arena Eternal (the place outside of time and space).

The Fanon tends to argue against the veracity of some of these sources, assigning different levels of theorized canonicity to the various references. But for most part ID's internal position is not known.

Levels of Canon

Note: This is general opinion of the Fanon, not necessarily developers or Bethesda's positions on the matter.

• Developer Commentary: Occasional discussions on what is canon in developers minds, but it is rarely touched upon. But some of this maybe ignored or superceded by later content, or rebooting of the series. The developers have never been clear on what is and isn't canon, although Hugo Martin has gone on the record to say every numbered game is indeed canon (including Doom 3). He later clarified that everything including Doom Reboot and Doom 3 links back through Doom 64. The Doom 64 Remaster supports this as the new backstory makes reference to the UAC Mars Research Facilities invasion from Doom 3 (see Doom Classic Bundle).
• Official Games (and Official Episodes): These are generally considered to be primary canon, or may comprise more than one canon (Master Levels & Maximum Doom really has no story (or unused 'fanfic' backgrounds for when the levels were originally intended to be fan wads)). Final Doom is stated to be two official episodes that fits into Doom canon.^[2] As per Doom I & Doom II the official episodes include: Ultimate Doom (four episodes), Doom II (one episode), Master Levels (later versions turn it into its own episode), Final Doom (two episodes), No Rest for the Living (originally packaged as a new official episode for Doom II in XBOX Live Arcade and PSN Doom, and later the BFG Edition), and Legacy of Rust (two episodes). And finally Doom 64 (and Lost Levels). Doom 3 and its two expansions generally considered to form its own thing (though some marketing tied classic Doom and RPG into it). Doom RPG generally considered its own series (though different releases have placed it in relation to classic or doom 3 timelines or put them in a shared universe), Doom Reboot (generally considered its own series but ties back into classic Doom through the multiverse). And various console ports and releases of Classic Doom and Doom 3 with various alternate levels.
• Manuals: Generally considered canon, but may contain contradictory materials in later releases of the games (BFG Edition Manual for example). Not all the manuals agree with each other, sometimes being replaced with new manuals with alternate information in later releases of games.
• Websites: These come and go, and are not often maintained and erased from the internet after a few years. Information is usually quite official, but only a few broken backups may remain.
• Id Multiverse/Universe: This is comprised of crossover material and confirmed 'shared universe/multiverse' of other iD games. These are confirmed by current and former iD developers, and tied into some of the games such as Quake Arena, and Quake Champions. In shared timeline in general most games (including the Doom RPG series) are in same universe (short of the 2016 reboot/Eternal which exists in a parallel universe) In another multiverse concept there is a Hell universe and multiple Sol systems. In this theory brought up in the The Art of Doom Eternal (and mentioned by Hugo Martin) is that classic doom (doom, doom I, Master Levels, Final Doom, No Rest for the Living, Legacy of Rust, Doom 64, and Lost Levels) are set in one earth universe, Doom 3 may be set in the same universe as Classic Doom (Doom 64 remastered appeared to reference the UAC Mars Research Facilities invasion from Doom 3, see Doom Classic Bundle), Doom 2016/Eternal set in yet another earth universe, but all three have been invaded by the same Hell (linking all the games into the same canon multiverse). Doom RPG's position as either parallel/continuation of other two universes (classic or doom 3) is unknown to this interpretation.
• Novels: These are generally considered non-canon (but official). The Doom 3 novel in particular mirrors Doom 3. Certain details and characters from the two books have been incorporated and influenced material in other games such as Doom RPG (but not necessarily adapted directly). Flynn Taggart and his Taggart Comic Group are referenced in Doom Eternal but how that relates to overall canon is up for debate (see Doom Reboot timeline and Doom novels timeline, Player Customization and multiverse for some possible theories).
• Movie/Novelization: Movies are official. But the canonicity of these sources are unknown (but generally considered non-canon). On one hand it takes place in an era largely not covered in other sources (Late 2020s-2050, see Film timeline somewhat similar to the Doom Timeline of the classic games), and thus could be seen as a prequel (to Doom 3, and taking place after original Doom series and Final Doom). On the other hand, its sort of a generic story, highly influenced by Doom 3's story. Almost a retelling without a proper demonic invasion (just humans mutating into monstrous creatures). But the novel might hint at very early invasions in ancient Mar's history. The sequel has an alternate Dr. Malcom Bertruger, and thus is less likely to fit with events of Doom 3.
• Sigil and Sigil II were officially added into Doom + Doom II’’ but is considered “unofficial sequel”.^[3] Likewise Sigil II and Hellion are considered unofficial spiritual successors. "SIGIL II is the unofficial sixth episode for 1993’s DOOM®.^[4] See Sigil timeline. Though other marketing for Doom + Doom II states: Sigil fits in between the timelines of DOOM (1993) and DOOM II. Baphomet, the gatekeeper of Hell, “glitched the final teleporter with his hidden sigil, whose eldritch power brings you to even darker shores of Hell. You fight through this stygian pocket of evil to confront the ultimate harbingers of Satan, then finally return to become Earth’s savior.”
• Add-Ons (AKA "official add-ons", Doom I Enhanced/Doom II Enhanced) and Mods/Featured Mods (Doom I + Doom II): Unless specifically stated these are considered fan made (non-canon). Only exceptions being No Rest for the Living and the two Final Doom episodes which are listed as “official” in the Doom I Enhanced and Doom II Enhanced release (all three have been moved over to Main game menu in the consolidated Doom + Doom II compilation. Featured Mods replaces the curated Add-Ons in latter release. In the later Doom + Doom II release both Final Doom, No Rest for the Living and the all new Legacy of Rust are incorporated into the main menu.

Crossovers

• Wolfenstein, Commander Keen, and Doom are connected according to Tom Hall.
• Wolfenstein RPG and Doom RPGs include crossover material with a number of ID series and each other. Even as much as mentioning Orcs & Elves series.
• Doom II RPG and Doom Resurrection have references to each other. The character Sam appears in Doom Resurrection until it is destroyed saving the player character's life, and its remains are rediscovered in Doom II RPG showing its final outcome. And the character Garrett is cross referenced in both. Both share the same sections of Hell named Gehenna and Abaddon.
• There are some crossover material between Doom, Doom 3, Doom (2016) and Quake Arena III, Quake Champions. The latter also has crossover with MachineGames Wolfenstein universe. Quake Champions is said to be a prequel to Quake Arena which also has version of Doom Marine from another era.
• Doom RPG and Doom 3 novels share details and backstory. Ian Kelliher, and the Doom RPG website claims that the hero is the same hero from Doom I, II, and Doom III. Deimos is already missing seemingly a nod to the original Doom.
• The backstory in Doom II manual is similar to the plot of Doom 3, with lone space marine saving Mars Base. Doom RPG also has a similar plot. The only difference is when these times take 'chronologically' (Doom 2 is likely roughly 21st century, and Doom 3/RPG both take place in the 22nd).
• The protagonist of the Doom 3 novels shares the same last name as the main character in Quake II (although there is no known direct connection between the two).
• There are crossover elements in R.A.G.E. such as Mixom corporation. However the game is likely in a parallel universe where earth asteroid hit earth on August 23, 2029, and main character wakes up 108 years later in 2135 which is only a few years before Doom 3/4 which are each set roughly in 2145-2149. Based on what is known about earth in Doom series its unlikely its as bad off as it was in Rage 10–20 years before. On the one hand asteroid Deimos was left to crash into the earth in a few years... Assuming events of the novels 'happened' in one timeline as well...
• Doom 2016 and Doom 3 are likely in alternate earth universes, although the same Marine apparently traveled through Worlds and Time to both according to Quake Champions, and info in Doom 2016. Alternatively Doom 4 might be set far in the future after a 'calendar change/year reset' (see Doom novels timeline).
• A comic in Quake for Saturn included and adventure following Quake Marines Dank and Scud run into the Doom Marine during their adventures. Assuming that Quake took place between 2008 and 2108, he'd either have had to have time travelled, interdimensional traveled, or the date would have to be set closer to the original Doom Timeline in the early 2020s.
• Although Doom 3 is said to be in same universe as Doom I and II (and Doom RPG) it is unknown if it is a prequel or a sequel in some fashion. Quake Champions is not clear, but just includes elements of the story in the back information for Doom Slayer, but does imply to be the Marine's first time on mars, and his first encounter with demons. The backstory for the Marine/Slayer is similar to manual prologue in Doom 1, however assuming that Doom took place in early 21st century (as per SNES and novels), then Doom 3 would have to occur in the far future (almost 120 years later) which would have problems with Doom 64 (unless Doom 64 was after Doom 3 and Doom RPG), but this would require for Doom Marine to have gone into stasis at some point on Earth most likely, before returning Mars. Doom 64 is implied in Doom 2016 and even more strongly in Quake Champions to be events that lead up to 2016 game.
• Doom 64 has a number of different backstories Nintendo marketed it as a tie-in to Doom I (Phobos), the remaster claims it’s a return to mars base (a reference to Doom II manual backstory, Doom 3, or even Doom RPG). While one backstory might even tie it back to Final Doom post Doom II see Space installation (Doom 64).
• Keel in Quake Champions appears to be based on Revenants.
• The UAC is mentioned ins ome of Quake 4's background. According to Quake IV: The "Armstrong" was an Orbital Space Station in low orbit around the Earth. During the Strogg invasion of Earth, it was used by the U.A.C. to study and store creatures and weapons developed on Mars. When the Strogg invaded Earth, the station had been turned into an Orbital Defense Platform, but it was ultimately taken down by the Strogg. During this incident, Kane found an old U.A.C. weapon which he used to survive. He turned out to be the only survivor of this attack, but The United Nations kept him quiet about this incident, leading to rumors that the weapon wasn't all he had found. As Quake II/IV takes place in 21st century and thus likely overlaps the orignal Doom Timeline, and there are no direct references to Strogg invasions in any Doom related materials its possible that Quake II/IV universe is also in a seperate earth of the iD multiverse.
• A level in a Wolfenstein 3D expansion has B.J. traveling to the future into a UAC base in an unknown location. In Spear of Destiny: Mission 3: Ultimate Challenge, Hitler has found a way via the occult to see into the future and even travel there, and he's stealing technology in order to give the Nazis and advantage over the Allies. At one point B.J. Blazcowicz is transported to the future into a UAC base where he sees UAC boxes, and Doom computer monitors showing the sun. Like in Doom its been invaded by a Demonic force (Devil Incarnate).
• All the collectable dolls/action figures in Doom 2016 are based on other ID franchise and classic Doom games.
• Rage has a secret teleporter leading to the first room of E1M1: Hangar. There, the player can pick up a Doom Marine Bobblehead. There are also similar secret areas calling back to Wolfenstein 3D and Quake.
• The Soul Cube appears in Doom 3, Doom RPG, Doom (2016), and Doom Eternal.
• Classic Doom games can be seen Doom Eternal/Doom 2016.
• Super Turkey Puncher 3 can be found in Doom 3 and Doom 2016.
• Sarcophagus holding a 'great Hero' (showing an image of Doom Marine) are found in Doom 3, Doom (2016),
• Stroggs are referenced in Doom Eternal.
• BFG10,000 (from Quake series) makes an appearance in Doom Eternal in a magazine.
• The last level of The Lost Levels for Doom 64 quotes the Slayer's Testement, linking it to Doom (2016)/Doom Eternal. Doom Eternal has a flash back to Doom 2016.
• Doom Eternal makes a number of references including to Daikatana, Half-Life, Doom Novels (Flynn Taggart), classic Doom games, etc.

Timelines

Depending in marketing and licensed websites and other official sources there are a number of different interpretations of the Doom canon timelines.

Crossover Multiverse

Timelines that links many of the various Doom universes together including the classic timeline as part of a greater 'multiverse'

• • Shared timeline - this timeline follows the 'soft reboot' of Doom 2016 (with all the dates from Doom 3 and Doom 4 series included. The original games positions are still unclear in relation of the soft reboots dates, although they we know they happened long before in Doom Slayer's past from his perspective). External/unused information states that Doom Slayer is from another Earth-dimension than that of the new series.

Note: These are based on the implied dates from Doom RPG, with Classic Doom taking place 'before or after' Doom 3)

• Console timeline (Console Doom series set in the 21st century (c. 2022) based on SNES Doom manual.]]
• Noteably there may be a timeline that is set in MachineGames universe. Some theorize that Machine Games might lead into the 2016/Doom Eternal universe, though the Doom Slayer himself is actually from a variation of the classic universe. Long into the future (after Terror Billy Blazkowicz defeated the Nazis in the 60-80s, after one of his daughters birthed Billy Blaze II, and after the Commander Keen twins (Billy and Billie Blaze III), etc.).^[5]

Games

• OT Doom timeline (classic Doom series set in the 21st century (as per the novels time frame (similar to SNES, but not specific), maybe as early as 2004) based upon the rough dates given in Doom novels, but only following the games stories)
• Nintendo timeline (Doom SNES/Doom 64 console releases)
• Doom Retcon Timeline (Classic Doom series set in the 22nd century based on Doom RPG dating)
• Doom 3 timeline (only includes information from Doom 3 game and its expansions)
  • ID timeline (Doom 3 as prequel)
  • ID timeline (Doom 3 as sequel)
  • Xbox timeline
  • BFG timeline
  • Doom RPG timeline (only includes information specific to Doom/Wolfenstein RPG games)
• Doom II timeline
• Midway timeline
• Saturn timeline
• Slayer timeline (timeline based on Doom 2016/VR/Eternal series, includes Art of Doom information as well).
  • Enhanced timeline
  • D64R timeline
  • LRG timeline

Third Party

• SIGIL timeline (timeline based on the classic Doom timeline with the addition of John Romero's SIGIL ("Episode 5"), Sigil II ("Episode 6") and Hellion, and Knee-Deep in the Dead E1b (these are considered unofficial/non-canon). Original Doom is set roughly May 2020 according to Romero certificate.
• Fan timeline (timeline based on classic Doom timeline with addition of various commercial, third party, and free fan mods) (this one is non-canon)

Novels

Doom 3 novels

For main article, see Doom 3 novels timeline.

Doom (2005 film/novel)

For main article, see Film timeline.

Doom novels timeline

For main article, see Doom novels timeline. (aka Flynn Taggart timeline). The original Doom is set in 21st century.

Development

• iD Timeline (timeline of Doom development history)

Quake series

• The Arena Eternal is an extradimensional structure created by the Vadrigar and populated with the greatest warriors in all of time and space. The Doom Marine, and other survivors of Phobos invasion: Crash, and Phobos were brought there from their eras to fight.
• Ranger is brought in from his own era to fight as well.
• 21st Century - The Global Defense Force, or GDF, is a supranational paramilitary organization, formed in the mid-21st Century from a large pool of national military organizations and relief agencies, to combat increasingly severe weather events, other natural disasters and terrorist campaigns, as well as to keep the peace in historically unstable regions such as the Middle East. It was created shortly before the Strogg invasion of Earth. The GDF is a fencible military, as opposed to the Space Marine Corps which is expeditionary.
• The Strogg invaded Earth in the mid-21st Century in search of biological components. The Strogg invaded the Earth in the middle of its 21st Century period, taking its inhabitants completely by surprise. Their large invasion fleet arrived in orbit over the world seemingly out of nowhere, and its ground forces quickly proved themselves a dire threat to the existence of Mankind. By the mid-21st century humanity is fighting for its survival against the hostile alien threat seeking to end the Strogg once and for all by invading their homeworld.
• Doom 3 references to Quake: Quake-43, Quakecon Games and Hunter (character).
• The "Armstrong" was an Orbital Space Station in low orbit around the Earth. During the Strogg invasion of Earth, it was used by the U.A.C. to study and store creatures and weapons developed on Mars. When the Strogg invaded Earth, the station had been turned into an Orbital Defense Platform, but it was ultimately taken down by the Strogg. During this incident, Kane found an old U.A.C. weapon which he used to survive. He turned out to be the only survivor of this attack, but United Nations kept him quiet about this incident, leading to rumors that the weapon wasn't all he had found.
• Doom imagery appears in Quake III Arena. The image of a Lost Soul on the lower side of Anarki's board. Another typical Doom image (Demonic head in a pentagram) can be seen on the back of Biker's jacket. There are also several images of the Icon of Sin appearing as wall decorations on some of the maps.
• BFG 10K (the next model after BFG 9K) appears in Quake II and Quake II Arena.

See also

Doom Bible

(Includes all events described or mentioned in the Doom Bible document by Tom Hall) The Doom Bible may of be some interest to individuals looking into the history of Doom's development. While the unused storyline doesn't have any dates to make a specific timeline (other than characters ages) there is at least a detailed list of events.

• Doom Bible

Notes

• Some Fanon does not accept developer comments, partly due to the fact that developers come and go, and varies per game. Many of the original developers on Doom to Doom II no longer work at ID software. And the developers of Doom 3 and Doom 2016 for example are different developers and sometimes different companies outside of ID software. Currently Bethesda owns the franchise and they have said little confirming or denying the status of canon or canons of the series.
• After the release of Doom (2016), there was fan speculation that the Doom Slayer's past included the interdimensional adventures of the original classic Doom Marine after Doom 64 in a new parallel earth (as confirmed in Quake Champions and his ties to "Daisy"), however many also consider Doom 3 to be in a seperate 'canon'/'alternate universe' from the other two, or at least Doom 3 Marine being a different individual than the one from the original series, even if from the same shared timeline. Quake Champions does contain information about Doom 3 Marine in the armor bios, but offers no explanation as to how it fits chronologically with the Classic Marine (but implying it may be the Marine's first encounter with demons, and thus a prequel to others), Arena Marine (Doom), or Doom Slayer (some fans point out that Quake Champions is about pulling characters from parallel dimensions that the skins could simply be "parallel universe' versions of Doom Slayer's character from several different Earth universes). The rabbit's foot and its description however is standard gear for the basic Doom Slayer character skin (and specifically refers back to the Doom Slayer in it's description), and Doom Slayer himself is pulled From Doom (2016) including his bio from that game. His other standard accessory gear is the backpack he keeps the mini versions of himself in (referencing all the dolls collected in the Doom 2016). Doom 64 has been included with Doom Eternal as a preorder bonus, and has an extra campaign confirming its part of the backstory to Doom Eternal..
• The introduction of the character in Doom II manual discusses a Mars invasion in the UAC Mars Base (sort of a precursor to the plot of Doom 3 and Doom RPG), and tells of a completely different set of events than occur in both the original Doom or Ultimate Doom endings which took place on Phobos and Deimos instead. Some Fanon believe this to mean that the marines in Doom 1 and Doom 2 are completely different individuals who reached Earth by different means (Mars hero by drop ship, and the Phobos/Deimos marine by teleportation).
• According to the Doom 64 manual it mentions "planetary" twice and "space installation" when discussing previous events. Some Fanon believes this may be a reference Phobos/Deimos invasion, while others believe it could be a reference to the Doom (character) it doesn't specify which."You, the tough Marine, are returning to a space installation you once saved from these vile beasts. Unfortunately you weren't as thorough as you thought, and their carcasses were resurrected."). Doom II introduced the Mars installation itself had also been saved from a demonic invasion (the base itself was also mentioned in the backstory for the original Doom). Only a short-story/article in Nintendo Power claimed it to be another base on Phobos.
• The nature of canon or canons is unknown, with hints at possibilities of there being a single timeline (and sometimes single character) for at least much of the material according to some interpretations (BFG Edition, and Doom RPG website), or a single canon including a doom multiverse with multiple parallel earths being invaded by the same Hell dimension as implied by Quake Champions and Doom 2016 (which could make Quake Arena/Champions events (see Doom (character)), the classic Doom universe, Doom 3 universe, Doom RPG universe, and Doom/Doom Eternal universe, each seperate but connected through Hell. Doom Slayer according to quake is directly connected to the original Doom Marine from Doom/Ultimate Doom, but appears to have been discovered in Hell by explorers from yet another parallel Earth universe, one in which actively worships Demons). But alternatively each iteration could represent their own seperate canons, divided into groupings including Classic Doom series, Doom 3 series, Doom RPG series, and Doom 2016 series (in which any 'nods' between each game would only be seen as 'Easter eggs' at the most).
• Some Fanon prefers to think of 'current' iteration as 'canon' and previous series Classic Doom series, or Doom 3 series, or Doom RPG series as non-canon (assuming they don't also acknowledge the idea that Doom Slayer is the Doom 1 Marine).
• Some Fanon (depending on individuals) do not accept "extra/additional/add-on" such as Maximum Doom, Master Levels, Lost Episode, Thy Flesh Consumed, No Rest For the Living, or stand-alone games such as Final Doom, and Doom 64, or console ports/adaptations (such as PSX/Saturn/GBA/SNES) as canon. Final Doom are essentially commissioned and repurposed megawads given stories by ID and retooled and reedited by ID software. Thy Flesh Consumed like Final Doom was partially designed in contrast with third party level designers the John Anderson (Dr. Sleep) level: E4M7: And Hell Followed was originally part of his Canto series and retooled by ID software (several of his Canto levels were also retooled by ID for the Master Levels). Some fans note it’s second confusing ending in conflict with Doom's original ending, as both more less end with the Marine ending up on earth from Hell discovering his Dead Daisy). In one sense at least Master Levels was not stand alone and is largely a bunch of individual level put together for ID under contract (many of which do not have stories, some stories that are included are not even set in the Doom Universe at all (but try to tell some kind of non-Doom backstory from when the levels were originally intended to be their own thing for when the levels were going to be released for free on the internet) . These synopsis are rife with spelling errors and lack of editing, and not even discussed in the manual). It however was commissioned, heavily curated and edited by ID themselves as an “official” dlc, and in later releases (PSX, Xbox, PSN and Doom I + Doom II) retooled into a proper episode of its own), with an “ending” screen. Maximum Doom is just a completely random compilation of stuff taken from the internet without much oversight (and no re-editing by ID). As such fans tend to consider none of its wads canonical.^[6] Doom 64 was originally designed as a third party product (Midway) with very little ID input (and no oversight). Doom 64 has since been officially released across platforms, and is no longer just an Nintendo 64 exclusive.
• A number of commercial campaigns such as The Lost Episodes of Doom, Perdition's Gate, Hell to Pay, Hacx , Action Doom 2: Urban Brawl, etc are simply third-party with no official ID involvement or licensing... Thus should not be considered 'canon' at all.
• Sigil and Sigil II is John Romero's 'spiritual' 'fifth episode' and 'sixth episode' (mods) to the Original Doom. However, is is considered unofficial to the original canon (as it originally was not endorsed, published nor owned by Bethesda^[7]). It also takes some liberties with the story lines presented in previous 4th episode (Thy Flesh Consumed) and the official Doom Strategy Guide. Noteably, whereas Episode 4 was supposed to have taken place in a city on earth during initial invasion, Sigil posits that it was actually some kind of limbo or purgatory before reaching earth (Stygian Abyss). That after defeating the mastermind in Episode 4, the Marine attempted to catch a portal to earth, but is sent into a deeper section of Hell, one ruled by Satan, and had to fight his way out to find another way back to Earth. Sigil was not officially produced by Bethesda, but it could be downloaded as an add-on to use with 2019 Enhanced released versions of Doom.^[8] And it has been added along with other "official add-ons" (of unofficial third party mods) to recent console ports as well.^[9][10] Betheda's Slayer's Club refers to it as 'revisionist history', and as 'unofficial sequel'. The description on the Add-On describes it as 'unofficial sequel' as well. The 2024 Doom + Doom II added Sigil to the main menu (noting its unofficial sequel status) along with other classic Doom games (plus Legacy of Rust), and updated later added Sigil II to the main menu as well.

References