Phobos Mission Control


Phobos Mission Control
Start of Phobos Mission ControlStart of Phobos Mission Control
Author John Romero
Port Limit-removing
Year 2016
Link Doomworld/idgames
This level occupies the map slot E1M4. For other maps which occupy this slot, see Category:E1M4.

Phobos Mission Control is a single Doom level for limit-removing ports released on April 26, 2016, by John Romero as a second warm-up exercise before working on a new FPS game, Blackroom. It is an alternate take on E1M4: Command Control.


Map of Phobos Mission Control
Letters in italics refer to marked spots on the map. Sector, thing, and linedef numbers in boldface are secrets which count toward the end-of-level tally.


Whenever you see any deep pits in slime pools, do not fall in. These pits are inescapable, and are type 16 damaging floors that will put an end to you quickly.

Switch 1

You begin in a semi-open air area. Head to the southwest, kill the zombieman and take the chaingun he was protecting. This lowers a ledge containing up to three shotgun guys, two imps, a zombieman and a demon. Grab yourself a shotgun (if available) and slaughter these enemies. Next, go to the switch marked "1" in the northeast of this area and flip it. This opens up a staircase in the west of this area, but also reveals a ledge in the north with a number of former humans and imps.

Switch 2

Head up the staircase in the west, then go south and follow the brown catwalk around. You will have some former humans and imps to deal with. Eventually, you will come to a thin ledge in the south of a slime pit. Kill the imp and zombieman in the alcove to the east, then follow the ledge onto the alcove and flip switch 2.

After flipping switch 2, turn around and an imp will be revealed on the chainsaw platform to the west. A burst from the shotgun will do. Also, a number of traps have opened on the brown catwalk. These monsters are not deaf, so lure them onto the ledge for a chokepoint, where you can easily mow them down with a chaingun. In total, you will need to kill a zombieman, three shotgun guys (one on Hey, not too rough and below), two imps (one on Hey, not too rough and below) and one demon.

Switch 3

Backtrack to the brown catwalk and head north. You will attract the attention of up to three demons. From the "4" sign on the floor, turn left, then left again. Descend the stairs into a computer room infested with more imps, demons and shotgun guys. Grab the armor and head southeast into a narrow passage. Shortly after entering the passage, the L-shaped computer bank to the west will open out with a large number of imps and former humans. Continue forward until the passage widens out into the southeast corner of the room. From here, take the right path, then the first right to enter a path that leads to switch #3.

Switch 4

Backtrack to the north of the computer room, then head into the passageway in the northwest marked "3". Follow this passageway to its end, where there is a staircase. Use this to get up onto one of a number of brightly lit ledges in this computer room. This ledge sequence has a number of traps:

  • Walk to the end of the first ledge. An L-shaped piece will rise to form a path to the ledge in the south of the room.
  • When you step onto the L-shaped piece, a large portion of the computer banks in the southeast will lower, releasing up to a zombieman, an imp, two shotgun guys and a demon.
  • Continue along the brightly lit ledge in the south. As you approach its end, a portion of the floor will rise up to join into another ledge in the north. A lift to the south will lower with up to two shotgun guys.
  • Continue north along this final ledge. Approximately 2/3s of the way along this final ledge, three small lifts with enemies will lower - one to the southeast with a shotgun guy, one to the northeast with an imp, and one to the northwest with another imp.
  • Flip switch 4 and collect the rocket launcher. A small trap will open to the west with a shotgun guy. Up to two shotgun guys will be released into the north of the room. A teleport trap will be activated, and up to three shotgun guys, an imp and a spectre will be teleported to various parts of the computer room. Enemies from a trap opened outside the computer room (up to two shotgun guys, two demons and two imps) may also enter the computer room.


Backtrack to the entrance of the computer room. From the "4" sign, head north, then east. Pull out your chaingun and mow down all the cannon fodder on the walkway ahead. Walls will open to the north, exposing you from fire from enemies across a slime pit, but they should not be too much of a problem. Be careful of a trap that opens to the south, which is designed to send enemies behind you while you are being caught up in dealing with the cannon fodder on the ledge.

Follow the walkway around to a platform. When you step on it, it lowers you into a large room with quite a number of enemies. Quickly rush to the south of the room and collect the items (including 4 shotgun shells, a clip, a box of rockets and a medikit. This lowers the grey structure in the middle of the room, revealing some shotgun guys, but also lowers a wall in the east of the room, revealing the bridge to the exit room.

Cross the bridge and walk around the two pillars instead of between them (this avoids triggering a trap). Open the exit door and put two rockets inside to clear out the exit room. Flip the switch in the exit room to exit the level.

Other points of interest[edit]

After completing the computer room and proceeding to the northern walkway, drop into the slime pit and head west. This leads into a slime tunnel containing a computer map. Use the switch next to it to lower a platform, which leads you into an opened trap opposite the entrance to the computer room.


  1. After flipping switch 1, head up the stairs to the west, then return to the area where you took the chaingun. One of the walls to the east will have a different texture now. Open it to reveal a secret room with four health bonuses, six armor bonuses and a soulsphere. (sector 21) When you approach the armor bonuses, a ledge to the west will lower, releasing up to two shotgun guys, an imp and a zombieman.
  2. While in the alcove with the soulsphere in secret #1, open the north wall. This reveals a secret corridor (sector 66) leading to a room with an imp. Once you flip switch #2, a door will open in this room, allowing you reach an isolated ledge with a chainsaw.
  3. Once you have raised the steps to the first ledge in the western computer room, head onto the ledge and continue walking forward to the first gap. As you approach the first gap, an L-shaped piece will rise out of the ground to fill the gap. When you step on the L-shaped piece, a large portion of the computer banks in the southeast will lower with enemies. Run onto this portion of the computer bank and ride it to the top. This leads to a secret passage in the east (sector 294) with nine armor bonuses and a soulsphere.
  4. Further along the ledges in the computer room (just before you reach switch #4), you will cross a line causing three small lifts with enemies to lower (this is shortly after you walk past the segment of ledge with switch #3 on it). Once you hear the lifts lowering, jump off the ledge to the north, go up the steps to the start of the first ledge and look northwest to find an octagonal lift that has lowered (it is directly west of the curved set of steps allowing you to easily reach the starting section of the ledges). Ride it up to the top to reach a secret passage. (sector 108)
  5. Follow the passage in secret #4 around until it goes north-south (beware of the shotgun guy in here). Once the passageway goes north-south, walk towards the two southernmost panels on the eastern wall. These are fake walls that can be walked through, dropping you onto a megaarmor. (sector 114)
  6. West of switch #4 is a computer panel with a yellow and black caution strip. Open it to access a hidden hallway with six armor bonuses. At the end of this hallway is an inset with a different texture. Open it to gain access to the isolated ledge (sector 160) in the southwest of the computer room, with six health bonuses. Follow it to a small sunken area with a box of bullets, a box of shells, a medikit and a megaarmor.


  • Linedef 1190 has tag 28 and action 38 (W1 Floor Lower to Lowest Floor), but there is no sector with tag 28. This is presumed to be an error; this linedef appears to be intended to lower sector 206 (the wall separating the room after the lowering platform from the bridge to the exit area) if the player accesses the exit area from the slime and runs west across the bridge, but that sector has tag 29 instead.

Demo files[edit]

Areas / screenshots[edit]


Routes and tricks[edit]

Current records[edit]

The records for the map at the Doom Speed Demo Archive are:

Run Time Player Date File Notes
UV speed 1:30.09 Bdubzzz 2021-09-10
NM speed
UV max 4:31.51 Joca64 2016-04-26
NM 100S 4:20.66 Jean-Charles Dorne (JCD) 2022-03-14
UV -fast 4:20.20 Coincident 2020-06-05
UV -respawn
UV Tyson 7:11.77 Joca64 2016-04-27
UV pacifist

The data was last verified in its entirety on April 12, 2022.


Player spawns[edit]

This level contains four spawn points:

  1. facing north. (thing 253)
  2. facing north. (thing 254)
  3. facing west. (thing 255)
  4. facing west. (thing 258)


Map data[edit]

Things 347
Vertices 1866*
Linedefs 1829
Sidedefs 3009
Sectors 321
* The vertex count without the effect of node building is 1513.


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

Technical information[edit]

File checksums[edit]

Phobos Mission Control is contained in a ZIP archive whose filename is Said ZIP archive has the following SHA-1 checksum:


The contents of are as follows:

File SHA-1 UTC timestamp
e1m4b.txt d6981fd46269d3bb22adf2a962e8b6c62179565e 26 April 2016 00:04:51
e1m4b.wad 46215ed8988e4fea8fdb458aa45e75a4c6f2d014 25 April 2016 23:59:27

Inspiration and development[edit]


  • This is the second map John Romero created with third-party editors (Doom Builder 2 and GZDoom Builder) rather than his own DoomEd. The first one was Tech Gone Bad.
  • Several multiplayer-only rocket launchers (things 260, 343, 344 and 345) are placed within deep inescapable pits in the southern slime area. It is unknown if this is intended as bait for unsuspecting players (in the style of MAP57: The Marshes), a means for the trapped player to kill themselves more quickly, or simply unintentional.


External links[edit]