Sabaoth

"Your duty has always been to die, soldier!"

- Sabaoth

Sabaoth is the third boss in Doom 3. He is encountered in the level Central Processing: Primary Server Bank in the CPU chamber. Killing him will reward the Player with a BFG 9000.

History
Sabaoth is actually Sergeant Kelly after his demonic transformation. Its 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 rather 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 "incident" still remains uncertain. While some affirm 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), others think 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 attempting to send a distress signal before the invasion, giving some weight to the latter interpretation.

Tactical analysis
Sabaoth follows a fixed movement pattern, driving around the room in a figure 8 pattern around the 4 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 it 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 the Sabaoth too much.

Getting close to Sabaoth is unwise, considering his claw attack. However, he can not run the player over with his tank treads. For ranged combat, Sabaoth fires a BFG shot at the player every several seconds or so. 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 they are 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 the Sabaoth to get out of its garage, then quickly hitting it with a charged Soul Cube and a salvo of 5 rockets. This should topple it on Marine difficulty. Also you can use any powerful weapon such rocket launcher, chaingun or plasma gun anyway as starter to begin the battle and finish him with the charged Soul Cube.

Another 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 you might lose a lot of health.

Another strategy is to launch the Soul Cube at him immediately, pull out the chain gun, 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 very quick if you get lucky and hit a shot right out of his cannon, and the chain gun is especially effective against stronger enemies, such as Sabaoth.

When playing in 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's 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 5 rockets and blow up Sabaoth's first shot before he changes direction for the first time. After that, 3-5 more rockets and another explosion should bring him down.

Trivia

 * The word "Sabaoth" is Hebrew for "armies". Ironically, the term is almost always a suffix for Jehovah, making Jehovah Sabaoth, or Lord of Hosts (or Armies).
 * Sabaoth bears a strong similarity to the style of cyborg enemies (especially the Tanks), called the Strogg, seen in Quake II. It also has a similar appearance to that of the Arachnotrons and Spiderdemons, as being an organic creature with a robotic, tank-like lower body.
 * Oddly enough, 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 just a bug, since the player is not really meant to hit Sabaoth in melee.
 * No matter where you killed the Sabaoth, its corpse will always end up in the middle of the room.
 * According to the Making of Doom III book, the idea 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.