MAP31: Wolfenstein (Doom II)

MAP31: Wolfenstein (named MAP31: IDKFA in the BFG Edition) is the first secret map of Doom II and can be accessed via MAP15: Industrial Zone. It was designed by Sandy Petersen and uses the music track "Evil Incarnate". The par time is 2:00. From this map, the player can choose between accessing the second secret map or returning to "normal" Doom II gameplay (by exiting to ).

Essentials
This secret level is based on Floor 1 of the "Escape from Wolfenstein" episode of Wolfenstein 3D, and the layout is fairly straightforward. From the start, go through the door ahead of you. Turn left and go through the door at the end of this hall. Continue through one last blue hallway and you'll arrive in a large grey room. Go through the door across from you once again. Proceed through the wooden hallway and through the door at its end. In the large wooden room, turn left, head through the door, around the bend in the next hall, and through another door. From the stone room, continue due south through another trio of doors. You will now come to an intersection; go left again.

Once in the final room, you can either flip the exit switch in front of you, which takes you to, or see secrets #2-3 for instructions to the super-secret level,.

Other points of interest
For those familiar with Floor 1 of the shareware version of Wolfenstein 3D, each brown-uniformed guard that appears in the "I am Death Incarnate" skill level is replaced with Wolfenstein SS (one on I'm Too Young To Die and Hey Not Too Rough, two on Hurt Me Plenty and four on Ultra-Violence and Nightmare) and the dogs are replaced by demons. In addition, the hallways appear larger and the guards smaller than in Wolfenstein 3D.

Official

 * 1) At the east end of the map is a blue, T-shaped hallway. Take the door at the south end of this hall into a room with several alcoves in the walls. The back wall of the southeastern-most alcove opens, revealing a decidedly non-Wolfenstein secret area (sector 21) containing a BFG9000, a megasphere, a super shotgun, and several backpacks.
 * 2) In the room with the (regular) exit elevator, instead of flipping the exit switch, open the southwestern corner of the room to reveal a secret area with a medikit. (sector 77)
 * 3) Open the western wall in secret 2 to reveal the secret exit elevator. It will take you to, the second and last secret map of Doom II. (sector 76)
 * 4) Before hitting the secret exit switch, open the southern wall of this last area to reveal a supercharge. (sector 74)

Non-official
These are a pair of hidden areas present in the original Wolfenstein game that do not count towards Doom's secret tally:
 * 1) In the first wooden hallway, the back wall of the western alcove opens.
 * 2) The painting of Hitler in the stone room in the northwest corner of the map opens.

Bugs
Two demons in sector 41 (on Ultra-Violence or Nightmare) occupy the same location, and are immobile until one is killed.

One Wolfenstein SS in the northern-most alcove in sector 51 has the ambush flag set, while his three companions are not.

Five large brown trees (Things 245, 246, 247, 248 and 249) in the square room in the west, with 247 and 248 placed on top of each other, have no flags set for any of the three difficulty classes, so they do not actually appear in the level.

Current records
The Compet-n records for the map are:

The data was last verified in its entirety on July 6, 2020.

Player spawns
This level contains seven spawn points:
 * 1) facing east. (thing 15)
 * 2) facing west. (thing 299)
 * 3) facing south. (thing 300)
 * 4) facing west. (thing 301)
 * 5) facing west. (thing 302)
 * 6) facing west. (thing 306)
 * 7) facing west. (thing 307)

Things
This level contains the following numbers of things per skill level:

Inspiration and development
The map is a replica of the first map of Wolfenstein 3D. There are however some key differences:
 * 1) The brown guards and German shepherds that occupy this floor in the original game are replaced by groups of four SS guards and demons respectively. The SS guards look and behave somewhat differently here, being weaker than their original counterparts, and their lines are derived from the Macintosh version of the game.
 * 2) The textures and sprites carried over from Wolfenstein are twice the resolution of the DOS originals. The SS soldiers have been scaled down to half their original size, presumably as enemies in Doom are seen from eye-level rather than chest-level as in Wolfenstein 3D. Conversely, the wall textures and by extension the level itself is twice the size of the original. This is because the textures come from the higher resolution Macintosh and Atari Jaguar ports rather than the original DOS version.
 * 3) id chose not to use the original map's elevator textures, so their textures are not present in the IWAD. Instead they used stock Doom II textures for the exit.
 * 4) The doors and push walls operate like Doom doors, despite their appearance. The Doom source code contains partially completed (but commented-out) code for horizontally opening doors, suggesting that it was at one point planned to make the doors open horizontally.
 * 5) The MIDI track used for this level is not the same as the original, and instead uses a track from the prequel game .

Trivia

 * This level was going to have horizontally sliding doors like the original Wolf3D. The code is still present but commented out.
 * The music in this map is from Spear of Destiny (Level 21, the Angel of Death), the prequel to Wolfenstein 3D.
 * While the secret in the southeast corner of the map is not in the original Wolfenstein 3D map, there is a secret in the same location in the Super Nintendo version of Wolfenstein 3D.
 * The 128x128 wall textures are taken from the Atari Jaguar port of Wolfenstein 3D (the same graphics were later used in the 3DO and Mac versions of Wolfenstein 3D), where they were used in the same dimensions of the original Wolfenstein 3D game. The only texture to display a significant difference is the red brick with a swastika. The wall RW35_1 used in regular levels in Doom II is also ripped (and slightly redrawn) from the Atari Jaguar port of Wolfenstein 3D.

Censorship
In the German version of Doom II, this level was entirely removed.

In the version included with Doom 3: BFG Edition, all Wolfenstein SS have been replaced with zombiemen. In addition, the map is renamed to MAP31: IDKFA, the music track used is Doom, and the Nazi iconography has been removed from the textures. However, the latter two changes have been made by modifying the resources instead of modifying the map. This has been known to cause multiplayer network game synchronization issues with the original Doom II when playing this level. A patch to un-censor the BFG Edition version is available.