40 (melee attack), 200 (BFG-9000)
Central Processing: Primary Server Bank
Sabaoth is actually Sergeant Kelly after his demonic transformation. His lower half has been transformed into a tank-like vehicle, while the upper portion is a twisted body attached to heavy machinery armed with a very sharp claw and a shoulder-mounted BFG. Sabaoth is large, being slightly taller than a Hell knight and significantly wider. His claw does 40 points of damage per strike, and his stolen BFG-9000 deals a massive 200 points. His BFG was taken from Jack Campbell.
The reason for Kelly's subversion and transformation still remains uncertain. While it is possible that he was working with Betruger and the demons since the beginning (substantiated by the fact that he insisted in contacting the Earth armada to bring them to Mars, maybe knowing it would be taken over by the demons), it is equally possible that he was captured, mind-enslaved and transformed by Betruger to serve him, and that his zealous attempts at contacting the fleet to get reinforcements were simply basic military logic (realizing that the battle is lost without reinforcements).
Jonathan Ishii—who is unlikely to have been allied with Betruger—was also attempting to send a distress signal before the invasion when Sarge issued orders to the player to find and arrest the scientist, lending some weight to the latter interpretation.
Sabaoth follows a fixed movement pattern, driving around the room in a figure eight pattern around the four pillars in the corners of the room. As the battle progresses, the pillars will open and close one by one, emitting electrical arcs that can damage the player if they are standing too close. Additionally, bridges will extend from the central platform to various side rooms where additional health, armor, and ammo can be found.
Sabaoth is a large target with tons of hit points and enough firepower to topple even the hardiest marine. The suggested route involves running and gunning, avoiding both Sabaoth's claw and BFG shots. Unleash the Soul Cube if it is charged and then pummel Sabaoth with rapid fire weapons such as the chaingun and plasma gun. The rocket launcher can be effective, provided the player can aim and fire the weapon without exposing himself to Sabaoth too much.
Getting close to Sabaoth is unwise, considering his claw attack. However, he cannot run the player over with his tank treads. For ranged combat, Sabaoth fires a BFG shot at the player every several seconds. A single direct hit from the BFG is almost always fatal even at full health and armor; however, the BFG projectiles are very slow moving and easy to dodge. Unfortunately, the BFG projectiles constantly emit secondary energy beams which deal continuous damage to the player for as long as he or she is in the BFG projectile's line of sight. It is arguably best to use small weaponry like the chaingun or the machine gun to destroy the BFG shots, since the player takes more damage the longer each BFG projectile is active; furthermore, disrupting the projectile soon enough should also catch Sabaoth in the ensuing explosion.
Another strategy involves waiting for Sabaoth to get out of its garage, then quickly hitting it with a charged Soul Cube and a salvo of five rockets. This will kill him quickly.
A riskier strategy involves launching the Soul Cube at him, running towards him, ducking and using the chainsaw on the tank section of his body while strafing right - it should kill him very quickly, but the downside is that you might lose a lot of health.
A final option is to launch the Soul Cube at him immediately, pull out the chaingun, and then fill him with bullets while sprint-strafing to the side, and—if possible—aiming to hit his BFG blasts. Using this method can be quick if you get lucky and hit a shot right out of his cannon, and the chaingun is especially effective against stronger enemies such as Sabaoth.
When playing on Nightmare difficulty, this is likely the toughest fight in the game if the player does not have a charged Soul Cube. Less than a second of exposure to the BFG rays will kill you, so it is best to use the rocket launcher constantly, as the splash damage will likely blow up the BFG shots the moment they are fired. There is enough time to unload five rockets and blow up Sabaoth's first shot before he changes direction for the first time. After that, three to five more rockets and another explosion should bring him down.
- The word sabaoth is Hebrew for "armies". Ironically, the term is almost always a descriptive suffix for Jehovah, making Jehovah Sabaoth, or "Lord of Hosts".
- Sabaoth bears a strong similarity to the style of cyborg enemies (especially the Tanks) called the Strogg, seen in Quake II. It is also reminiscent of the earlier arachnotrons and spiderdemons, being an organic creature with a robotic, tank-like lower body. The later Doom hunter shares these traits as well.
- Oddly, when rendered motionless with "notarget", melee attacks with fists, chainsaw or flashlight can draw blood from the lower tank section of Sabaoth (strangely, considering its mechanical nature). This is probably a bug, since the player is not meant to hit Sabaoth in melee.
- No matter where Sabaoth was killed, its corpse will always end up in the middle of the room.
- According to the book The Making of Doom 3, the original intention for Sabaoth was that Sergeant Kelly's torso would be crucified onto a demon, which in turn would be fused with a tank. The demon Sabaoth would then use Kelly's military experience and knowledge to its advantage. Some of this concept, however, was "lost in translation."
- Sergeant Kelly's transformation into his Sabaoth form may not have happened until after he killed Campbell, as the corridor he ambushed Campbell in is too narrow for Sabaoth's body.