Doom 3 Cheats

Skip checkpoints:
Hold L and press B, A, X, Y while playing the game to advance to the next checkpoint. A sound will confirm correct code entry.

Invincibility:
Hold L and press X, Y, B, A while playing the game. You will hear a sound if you have entered the code correctly. To verify that it is enabled, fire any weapon with splash damage at a nearby wall. REMEMBER: The code cannot be enabled until you take the elevator after being attacked at the start of the game. When a new area is loaded, the code must be re-enabled to regain its effect.

Doom Ultimate and Doom 2: Cheat mode
Submit one of the codes below while playing the game. You will hear a sound if you have entered the code correctly. Repeat the code to disable its effect. REMEMBER: These games are only available in Doom 3: Collector's Edition.

Doom Ultimate and Doom 2: Toggle God and Degreelessness mode:
Hold L and press A(4).

Doom Ultimate and Doom 2: All weapons, health, keys, and armor:
Hold L and press B(4).

Doom Ultimate and Doom 2: Temporary invincibility:
Hold L and press X(4).

Doom Ultimate and Doom 2: Full map:
Hold L and press Y(4).

Doom Ultimate and Doom 2: Berserk mode:
Hold L and press X(3), Y.

Doom Ultimate and Doom 2: End level:
Hold L and press A(2), B(2).

Doom Ultimate and Doom 2: Chainsaw:
Hold L and press B(2), A(2).

Doom Ultimate and Doom 2: Invisibility:
Hold L and press X(2), Y(2)

Doom Ultimate and Doom 2: Light Amplification Goggles:
Hold L and press Y(3), X.

Doom Ultimate and Doom 2: Radiation Suit:
Hold L and press X, Y(3).

Nightmare mode:
Complete the game once under any difficulty setting. When you start on Nightmare Mode. you will start with the Soul Cube.

Cabinet combinations:

Cabinet 001: 396
Cabinet 003: 483
Cabinet 009: 752
Cabinet 013: 586
Cabinet 017: 347
Cabinet 023: 531
Cabinet 038: 409
Cabinet 039: 102
Cabinet 047: 123
Cabinet 048: 123
Cabinet 049: 123
Cabinet 054: 246
Cabinet 054 (second): 142
Cabinet 063: 972
Cabinet 064: 651
Cabinet 078: 364
Cabinet 079: 364
Cabinet 103: 259
Cabinet 104: 579
Cabinet 112: 538
Cabinet 114: 715
Cabinet 116: 972
Cabinet 116 (second): 624
Cabinet 117: 624
Cabinet 213: 371
Cabinet 215: 298
Cabinet 216: 624
Cabinet 217: 624
Cabinet 317: 841
Cabinet 386: 836
Cabinet 387: 836
Cabinet 452: 571
Cabinet 666: 372
Cabinet 669: 468
Martian Buddies 1 and 2: 0508
Weapons Storage 1 and 2: 584
Monorail Override Junction 5: 826
Monorail Override Junction 5 Junction 7: 953

How to beat the final Boss:
When you each the end Boss, do not bother wasting your ammunition on him. Just stay away from him. Kill the Imps and other demons and use the Soul Cube on him. If you are play in co-op mode, shoot him. Use the Soul Cube on him about five or six times. On the last time you will see an intermission sequence of him dying.

How to beat the Guardian Of The Soul Cube:
When fighting the Guardian Of The Soul Cube in hell, do not bother shooting his body. This is a waste of precious ammunition. Instead, blast his "searchers" with something with good coverage like the chaingun, and he will have to spawn more. When he does, a blue light will appear over his body. Shoot it with the rocket launcher. Do this a few times and he will die easily. Also, look in the room around the columns for ammunition, health, etc.

How to beat Sarge:
Be prepared to die a few times. Beware of the edge of the room, as you can fall off. Also, do not hide behind the pillars for too long. They will open up and arc electricity periodically. When you walk into the room, a giant bay door at the opposite end of the room will open, revealing the "new and improved" Sarge. As soon as that door opens a crack, start lobbing rockets in there. After you score about six good hits without being splattered by his BFG, break out the Soul Cube (that you should have charged before entering the room) and let him have it. It should kill him and heal you. Pick up the armor and ammunition around the room before continuing.

How to beat Imps:
If the Imp is jumping at you, blast it while it is in the air with the shotgun to kill it in one shot. This is slightly difficult to time.

How to beat teleporting demons:
When a demon teleports in (generally signaled by whisperings, a red tint throughout the screen, and always red lightning in the location where they will appear), you will have a split second before they are able to attack. Take a good weapon (for example, a shotgun or chainsaw for imps and wraiths) and stand close by. For powerful creatures, such as Pinkys, use a ranged weapon and stand at a safe distance. Remember to save the game often

Saving ammunition:
If you can avoid it, try not to use weapons like the shotgun or others that have difficult to find ammunition on the weaker zombies. The flashlight (if you are fast enough) or just the pistol usually will suffice.

Pumped up Soul Cube:
After you acquire the Soul Cube, equip it and wait about one to two minutes. It will reveal its blades and spin for a very short time.

Bathroom scare:
After you have found the lost scientist and are returning to the main building, find your way back to the bathrooms. Stand in front of the mirror with your pistol then cycle through until your shotgun then get very close.

Doom 3 Official Game Site

Doom 3 Review - Game Chronicles

Doom 3 Review - IGN