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Doom 3 maps

MARS CITY - "Mars City is the gateway to all Union Aerospace's Mars City Base. All Arriving personnel are processed here before moving to their assigned posts. Mars City houses the primary Marine Operations control room as well as the Main Administrators Office."

Mars City is the first level of Doom 3, consisting of a short tutorial on the basic features of the game. The player also picks up the first assignment from Sergeant Thomas Kelly ("Sarge"). It is the only level in the game to not include any enemies or usable weapons.


The game begins with a short video introducing the Union Aerospace Corporation (UAC), an interplanetary company that operates above and beyond all legal and moral obligations in the development of the most advanced technology known to man.

Mars City Hangar


Following the UAC presentation, the game cuts to a display showing the approach of a transport coming in for a landing on Mars. The dropship contains Counselor Elliot Swann and his bodyguard, Jack Campbell, who have come to Mars to check up on Dr. Malcom Betruger. According to Swann, Betruger has overstepped his authority in some way, and Swann and Campbell are there to bring him back into line. You are also on the transport. As a Marine who's been called up to active duty on Mars, your first duty is to report to Marine Command and receive your orders. As soon as the opening cinematic ends, walk forward and speak to R. Cooper, who tells you that all new arrivals must be processed at reception.


Follow the walkway to the Security Checkpoint’s doorway. You pass M. Caseon, seated on a bench. This disturbed fellow says he needs to get out of here, and he encourages you to do the same. He advises you not to trust anyone. Behind Caseon is a control panel with a transfer manifest on it. When you approach it, your reticule changes to a cursor; inspect the items on the manifest: two bins of administrative supplies, several crates of sealed biological specimens, and three metaseal containers of classified material. You can delete any of the items from the manifest if you wish, except the classified metaseal containers. Doing so has no effect on the game. Proceed through the door to the Security Checkpoint. Note that the door has a green light on it, indicating that it is unlocked. The door's display panel says "General Access," meaning that anyone can go through it.

Security Checkpoint


Walk into the Security Checkpoint where a technician tells you to stand on one of the red squares on the floor so that he can begin your bio-scan. After the technician ensures that you're not carrying any dangerous bacteria or pathogens into the facility, the door to the north opens into the Departure Lounge. Go through the door.


  • Personal
  • Adam Berneche
  • Note: If you spawn a weapon using cheats and kill a character who possesses a PDA, the PDA will appear in your PDA display under the name "Duncan Mathews". If you do this before receiving your personal PDA, it will take your PDA's place.

Email Downloads (Personal Email Inbox)

  • Director W. Banks / Welcome Message (already in PDA)
  • Sergeant Kelly / Report To Marine HQ (already in PDA)
  • Safety committee / Safety Awareness Month
  • UAC Security / Code-Black: Missing Staff
  • HR Coordinator / New High Score!
  • HR Coordinator / Volunteer to earn extra credits

Video Disks





Note: If you use the "noclip" cheat to reach these items, you may take the weapons to use later in the game, giving you an advantage up to the EnPro Plant

Cabinet/Door Codes

  • Storage Cabinet #001: Supplies - 396 (Note: If this cabinet wasn't opened, it will be open after you return from the old communications facility)
  • Weapons Storage - 584 (Note: This door cannot be opened even if the code is entered correctly)


  • At several points in this level, soft-drink vending machines can be found, dispensing Thirsty Burst (whose logo resembles a past 7-Up logo, but the background is yellow rather than green) or Robo Cola (resembling a generic cola logo, with white graphics on a red background).