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. His lower half has been replaced with a tank-like vehicle, while his upper half 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, taken from Jack Campbell, deals a massive 200 points.

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, and by his phrase, "Your duty has ALWAYS been to die, soldier!"), others think he was captured, mind-enslaved, and transformed by Dr. 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). It is also worth noting that 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 should he/she stand too close to them. 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 him 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 cannot 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, even on Recruit difficulty; 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.

The best strategy to take down Sabaoth is to launch the Soul Cube once you start the fight. There are plenty of enemies earlier in the level that you can use to power the Cube, but leave it charged and unused for some time before you meet Sarge. Hide behind the four pillars in the corners of Sarge's square to shield yourself from his BFG shots, so long as they aren't arcing. You can then take him down quickly by using powerful weapons like the Rocket Launcher, Chaingun, or Plasma Gun to finish him off after that. The chainsaw is also effective if you duck under his tank section of his body while strafing right.

Related achievements

 * You're Not My Boss! - Defeat Sabaoth boss

Trivia

 * Sabaoth is the only boss in the game that doesn't have an introductory cutscene.
 * The word "Sabaoth" is Hebrew for "armies". Ironically, the term is almost always a suffix for Yahweh, forming "Yahweh 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. He also has a similar appearance to that of the Arachnotrons and Spiderdemons, being an organic humanoid demon with a robotic, tank-like lower body.
 * A similar monster appears in Doom Eternal in the form of the Doom Hunter (a humanoid on treads).
 * Oddly enough, given his mechanical nature, when rendered motionless with "notarget", melee attacks with fists, the chainsaw, or the flashlight can draw blood from the lower tank section of Sabaoth. This is probably just a bug, since the player is not really meant to hit Sabaoth in melee.
 * No matter where Sabaoth dies, his 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 his 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. However, it is possible that this is not the case, as a dying Swann does say to the player, "he's no longer human", implying that Kelly had already been transformed into Sabaoth, possibly without the tank modification at that time.
 * The character Sarge in the Doom movie bears a resemblance to Sabaoth, as they were both allied to the protagonist before being transformed by antagonistic powers, defecting, and then being killed by the protagonist. It's also possible that Sarge is based on Kelly.
 * The name "Sabaoth" is never used in the game. Even the demonic voices which taunt the player about his upcoming confrontation with Sabaoth always refer to him as "Sarge" ("Sarge will destroy you!", "Sarge is waiting for you.", etc.).