This article is a stub. Please help the Doom Wiki by expanding it.

This is about the marines that appear in Doom 3. For the marine that the player controls, see Doom's protagonist.

In Doom 3, the player may occasionally come across friendly Marines. Marines are usually equipped with a Machine Gun, combat helmet and body armor, but are less skilled (and not as lucky) than the player. Marines are never seen in active combat during gameplay, other than in multiplayer. However, during a cutscene, the Marines of Bravo Team are seen being ambushed and killed by a group of Imps and Wraiths. They are also seen on camera views and heard over the radio trying to defend their positions and fight off the demons.


Marines in combat.




Background, storyline, gameplay, etc.


A Marine in full gear.


The Marines are responsible for security and defense at the UAC facilities on Mars. They are purported to have come from the United Nations Space Marine Corps, which is reinforced by the Doom 3 novels (while not directly stated in-game, their names are all generally American). In the game, Marine HQ is the hub of activity for the Marines and their subsection, Mars-Sec (short for Mars Security), and is also one of the main air and space traffic control centers for Mars City. Marines and Security personnel are stationed and/or patrol throughout the base, in and around areas including the EnPro Plant, Alpha and Delta Labs, the Monorail, and most visibly in Mars City where the Marine HQ and the primary Armory is located. In the character's PDA, a video disc about the Marine's role on Mars states that all Marines are under the command of Master Sergeant Thomas Kelly, who tries unsuccessfully to contain the invasion before being corrupted.

The Marine Corps also apparently possesses a number of spaceships of its own, which the player is commanded by Kelly to call for backup from the UAC Base's primary communications center. Whether or not the player sends the transmission himself, it is still sent - and when the Earth fleet finally arrives to back up Mars, they find the planet wrecked, and only one Marine left alive who had almost single-handedly stopped the entire demon invasion.

Marine characters

Marine and Mars-Sec teams

Weapons, vehicles, technology, etc.


  • There are Doom 3 mods that enable the player to have Marines on their side to help fight the demonic forces.
  • The Marine staff is stated to have increased in Doom 3: Resurrection of Evil; this is supported by more dead Marines in the expansion.
  • The Doom Protagonist from the first Doom was part of an unidentified Marine squad stationed on an unknown outpost on Mars, before being sent to Phobos due to a distress called and were Killed in Action.
  • A reoccuring gag (known as the "Useless Allies" trope) all unpossessed marines, except for a certain few (such as Doomguy) are shown to be extremely incompetent, and reckless, being killed by weaker demons and possesed security guards extremely easily.


Allied Marine Squadmates: A popular AI ally mod for Doom 3. Adds characters such as Campbell and Sergeant Kelly, as well as more minor characters such as Bravo Team, Fireteams 2 and 4, and Recon Zulu as functional AI units. Those and others are also included as "followers" that the player can lead, rather than standing in place and talking, like usual.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.