Sigil is a Doom PWAD developed by former series designer John Romero, with a high quality soundtrack composed by Buckethead and an oldschool MIDI soundtrack by James Paddock. It serves as the unofficial fifth episode for the original Doom. It was announced on December 10th 2018, the same date as Doom's 25th anniversary, with a release date on May 31 2019 for free users. Those who ordered the limited edition got the mod on May 22 2019.
After killing the Spider Mastermind in "Thy Flesh Consumed", Doomguy prepares himself to go back to Earth and save the planet from the forces of Hell, but Baphomet (the Icon of Sin) drags him to the deeper depths of Hell after sabotaging the final teleporter with his powers. Now Doomguy must slaughter every demon that stands in his way in order to return to Earth.
The mod can be downloaded here, and is available officially as free DLC for the current console, smartphone, and PC releases of Doom.
- Dragged Off to Hell: How the episode starts. Your mission is to get out of there.
- Drought Level of Doom: Or rather, Drought Episode Of Doom; SIGIL is notorious for its maps having a rather low amount of available health pickups, and ammo being scarce, especially non-Shotgun ammo. It's also stingy with weapon pickups, so those pistol starting each map will be stuck with just the Shotgun for large chunks of most maps. While it never gets as unfair in this regard as Hell Beneath was in Ultimate Doom and you'll always have enough ammo to kill everything without having to resort to melee, there isn't a lot of room for error on UV difficulty throughout the whole WAD, and you're going to need to sometimes kill Barons with just the Shotgun or berserk fist with little room to maneuver, especially if you miss some vital secrets.
- Early-Bird Cameo: Baphomet, the one who pulls you back to Hell, is the Icon of Sin, final boss of Doom 2. You don't actually get to fight him in this one.
- Interquel: Takes place between the original game and Doom II.
- Nintendo Hard: This WAD was designed to be a lot more consistently difficult than Episode 4 of Ultimate Doom was, with frequent cramped combat scenarios, and a general lack of health, ammo, and strong weaponry. While far from the hardest WAD out there, more casual Doom players jumping in on UV and expecting something on the level of the original two Dooms because they heard Romero made it will be in for a rude awakening.
- Number of the Beast: The Megawad with the Buckethead soundtrack is listed for 6.66 (About $8 US) on Romeros website. Additionally, the "G" in the WAD's logo is a stylized 666.
- Underestimating Badassery: Baphomet apparently thought that trapping Doomguy in the deepest part of Hell would seal his fate. Needless to say, Doomguy proves to be too tough to contain.