E1M4: Command Control (Doom)

E1M4: Command Control is the fourth map of Knee-Deep in the Dead in Doom.

Walkthrough
Start by collecting the secrets, if you like, described below.

Take any of the corridors and you will soon arrive in a round room, near the center of the map, containing a round structure with four doors. Approach any of the doors and they will all open; but be careful, there are imps inside. Go inside and collect the blue keycard. If the doors should happen to close while you are inside, simply walk again over the small lighter-colored square where the blue keycard was.

Exit the round structure to the west and continue out of the larger round room also to the west. Turn south and you will see the blue door ahead on the right.

Go through the blue door into a maze. To get through the maze quickly, take the first right and bear slightly left to go down a long corridor heading north. As you near the end of the long corridor, turn right, then immediately left, and then left again. You will notice the wall texture changes in the hallway ahead.

Go into that hallway, turn right, and you will see the yellow keycard. Collect it, continue down the hallway and up the stairs, and you will see the yellow door. But before going through it, click the red-colored switch to its left (raising the bridge leading to the exit door).

Go through the yellow door, turn right and follow the room around to the left. There will be a door on your right and stairs on your left. Optionally go through the door to see the platform that was formerly swastika-shaped (see development changes below). To finish the level, go up the stairs and across the bridge to the exit door.

Secrets

 * 1) Immediately where the player starts, there is a secret door on the south wall leading to a room containing powerups.
 * 2) In the second room (where a soul sphere is visible), take the far south corridor.  Drop down into the slime "river" and go east.  There is a room here containing a rocket launcher and various other powerups.
 * 3) While standing on the elevator it is possible to activate the switch next to it and cause the elevator to rise (although it is difficult; if done incorrectly, the elevator may rise without the player).  The soul sphere is then accessible.

Demo files

 * [[Media:e1m4secr.lmp|No monsters, 100% secrets walkthrough]] (([[Image:e1m4secr.lmp|file info]]))

Ledge run
It is possible to jump across the nukage pool and onto the ledge in the nukage room in the north west part of the map. This allows one to grab the yellow key and exit the map without grabbing any other keys.

The story behind the discovery of this trick is given by Compet-N:


 * The first player to discover the trick was Steffen Winterfeldt, who sent his demo to Yonatan, but for some reason this was not included in COMPET-N. Later, Jonas "Chrozoron" Feragen independently discovered the trick. As he was never a COMPET-N player, he sent his demo to Yonatan, who did not upload this either. Later, Rudy Jurjako also discovered the same trick. He somehow sensed the truth in his text file: "I have a hard time believing that I was the first to discover that jump...". Just one day later, Ralf Schreivogel also discovered the jump, not knowing of Rudy and the other people.

Rudy Jurjako's demo was e1m4-017 (August 18, 1998), beating Yonatan Donner's e1m4-022. The best time using this trick is e1m4-016 by Adam Hegyi (August 25, 1998).

Romero has confirmed in a reply to Adam Williamson that the trick was inserted deliberately:


 * Here's the answer, straight from The Man who mainly designed E1M4, Tom Hall: "Heeeeeeeeeee. Yeah, I'm pretty sure. :) But not sure if you can get to it.... it stops before it gets to the stairs now...so I think you'd have to get propelled backward somehow... so long ago though...


 * I totally forgot that this was in episode 1...man, I should play it again...yeah, like I have time..."


 * So... i think he *did* design it for a shortcut.


 * John Romero

Exit jump
Using strafe 50, it is possible to jump across the 192 units wide gap in the exit room, completing the level without grabbing any keys at all. This trick was created by Adam Hegyi and first used in e1m4-014 (June 8, 1999). The time was subsequently refined down to 0:13 by Jonathan Rimmer and ultimately 0:12, believed to be optimal, by Adam Hegyi again.

The same jump can be done without strafe 50, by rocket jumping. Due to the time involved in grabbing the rocket launcher in the level, this mainly saves time in the NM100S run.

Records
The Compet-N records for the map are:

Development changes


E1M4, started by Tom Hall and finished by John Romero, can be found in primitive versions in the 0.4 and 0.5 alpha versions of Doom, both as E1M7.

The version of E1M4 in Doom 1.0 contained a structure formed as a swastika (visible in the upper-left center of the 1.0 map to the right), inserted as homage to Wolfenstein 3D. The symbol was changed to a shape that only loosely resembles a swastika for version 1.4, as John Romero has commented :


 * "Yes, [in Commander Keen 5] there is a swastika in one of the levels, one of my levels to be exact, but I removed it shortly after the game was released because people were upset that an evil symbol was in a cute kid's game (the changed version is in the screenshot). It was a premonition of things to come, namely, Wolfenstein 3D. I also put a swastika in Doom ' s E1M4 as a Wolf3D reference, but I changed it later for the exact same reason."