The Machine Gun, also known as the MG-88 Enforcer, is a weapon introduced in Doom 3, drawing inspiration from the Chaingun in the classic games. It is essentially an assault rifle, with a large magazine size, high rate of fire, and great accuracy. Its default key is 4. The Machine Gun uses ammunition from clips.
The ammo counter is on the weapon itself and not on the game HUD - similar to the Chaingun, Plasma Gun and BFG 9000. Also, unique to the Machine Gun is that it has a built-in "buzzer" alarm which activates when the current clip has been reduced to 10 bullets, suggesting the user to reload. The Chaingun also has this built in alarm.
The Machine Gun is excellent in medium to long range combat against lightly armored foes. Zombies make the best targets, being slow and weak. The Machine Gun is also effective at taking down hordes of lesser demons, such as Trites, Cherubs and Lost Souls. The Machine Gun is most effective against Z-Secs (aside from those armed with Riot Shields) as it takes down them down quicker than the pistol, especially when they are hiding behind cover. In a tight spot, Machine Guns are good against Maggots and Imps as well.
While a very versatile weapon, the Machine Gun has its drawbacks. Each bullet does a lot less damage than the pistol. Therefore, it is not effective against tougher enemies such as Demons or Commandos in close range, as they can easily withstand a couple of bullets before rushing in to finally attack you. The Machine Gun also burns through its magazine quickly, requiring you to reload the weapon occasionally before every firefight.
Overall, while the Shotgun is an ideal defensive weapon for close range, the Machine Gun is an ideal defensive weapon for mid to long range scenarios, whenever an enemy surprises the player from a distance.
- An assault rifle was originally going to be used in the original Doom game. First-person sprites for it exist in both the 0.4 and 0.5 alphas. Its 0.4 appearance appears to have been a modernized MP40 (an obvious callback to Wolfenstein) but its later 0.5 appearance is similar to some sort of 7.62mm Assault Rifle.
- In Doom 3: Resurrection of Evil, it is now the main starting weapon in Multiplayer, while the pistol acts as the Sidearm.
- The Machine Gun is probably based on the FN P90 personal defense weapon, with UAC design. Strangely, the in-game weapon only has rear sight notches up the front, with no front sight present on the gun, making them unviable outside of close quarter combat.
- In reality, such weapon with aesthetics cannot be used for long range combat.
- This is actually the first weapon the player will come across in the game. Majority of the NPCs (i.e. J. Yezback, S. Holmes, and E. Grafton) in the first level will be seen holding this weapon while performing their duties.
- Although the Marine is commonly seen with the Shotgun in most cutscenes, only few instances depict him holding a Machine Gun. He is seen holding it on the introductory cutscenes of the Wraith, Revenant, and the Hell Knight. He also holds it in Monorail: Facility Transport, in the cutscene where the tram crashes.