BFG 9000 (Doom 3)

The BFG 9000 (initials for "Big Fucking Gun") of Doom 3 is one of the weapons created by the Union Aerospace Corporation under its weapon research programme, and is considered the most powerful weapon of the game. It is first introduced in UAC Administration, when Campbell opens his suitcase to an unknown green glow (green being associated with the colour of the BFG projectile). It is seen being used in Alpha Labs Sector 4 and Communications by Campbell, however, the player only manages to wield it starting from Delta Labs 2A. It is lost during the transits to and from Hell (where it is available as a pick-up), but the player manages to retrieve it again in the CPU Complex by taking it from the corpse of Sabaoth, who had stolen it from Campbell after leaving him fatally wounded.

Weapon schematics
The BFG in Doom 3 functions in a largely different way from its Doom counterpart. Comparing the weapons visually, the Doom 3 version is more compact, lacking a harness, has a shiny smooth metallic framework versus the original's rough design studded with various technological implements, and totally lacks the corrugated aperture that was shared with classic Doom's plasma gun.

The BFG9000's projectile consists of a computer chip contained within a massive ball of relatively slow-moving green plasma, the strength of which is determined via a charge-based system: holding down the trigger causes the weapon to charge through four different power levels for a more powerful shot, the status of the charge being displayed on the weapon's integrated monitor (which also displays the ammo count, dispensing with a game HUD, just like Plasma gun, Chaingun, and [Machine gun]]). Caution must be utilized, as if the weapon is charged beyond the fourth level, the weapon will explode and will instantly kill the player wielding it. This is referenced in-game as a glitch in the prototype weapon's design which was still being worked on by the UAC's tactical arms research and development team.

The projectile's embedded computer chip contains a sophisticated system, and, similar to the BFGs found in the Quake series of games, fires green energy rays at opponents which debilitate them prior to the detonation of the plasma projectile. The damage of these rays is around ten points per second. If the computer core in the projectile is destroyed before the projectile impacts with a surface or soft target, the explosion will be suboptimal, though can still deal considerable damage at close range. This makes use of the plasma gun in countering an enemy's BFG shots critical.

The effects of the weapon are devastating: a projectile charged at the lowest level can obliterate any weaker monsters, whereas a fully-charged shot will kill any monster with health equal to or less than the Vagary. "Elite" monsters with high hit points such as the Hell Knight or the Mancubus generally require a double or triple-charged shot to kill, and this weapon is ideal for dispatching Arch-viles quickly when the Soul Cube and Artifact are not available.

Unlike in the classic Doom and Doom II, the BFG 9000 in Doom 3 no longer uses the same ammo as the plasma gun, but has its own type of cells instead. The BFG cell is a small green cylinder with an actively vibrating sphere inside, with an appearance similar to an atom, and holds four charges. Unlike in Doom II, BFG cells are extremely rare and often placed in relatively obscure locations, and it is therefore recommended to use the weapon sparingly.

Tactical analysis
The weapon is recommended for medium to long-range combat, as firing at a monster up close will severely damage the player from the blast radius. Moreover, the longer the projectile exists undetonated, the longer the time it will have to attack other enemies within the vicinity with its rays. The BFG is also recommended for usage in areas with heavy enemy presence due to its targeting system, as the other weapons specialize more in single-enemy combat. It is also advisable to deploy the weapon for boss fights, such as in Caverns 2, due to the heavy premium on the ammunition.

Do not overcharge the weapon, as it can overheat and explode in the player's grip, killing him instantly.

BFG 9000 Briefing (Video Disk)
Creator: UAC Advanced Weapons Date: 10/10/45 Informational video on the BFG 9000

''Representing the pinnacle of UAC research and design, the BFG 9000 is the most advanced firearm ever designed. Fully self contained and deployed is a handheld platform it is capable of an excessive amount of fire power. The BFG 9000 contains sophisticated friend or foe technology that discriminates targets in real time.''

''Each projectile contains a small but very powerful computer core that actively maintains targeting and delivers a stream charge down each beam to soften targets before detonation. The detonation stage of the projectile is devastating. Targets within 15 meters of the flashpoint are not likely to survive.''

''While not recommended for small quarter combat, the BFG 9000 is ideal in the field and against movable targets. The only foreseeable defense is small arms ballistics. If the projectile is destroyed before exploding, the computer core cannot process the final fusion reaction, resulting in a less than optimal detonation. For more information contact the UAC's Advanced Weapons Department.''

Expansions
The BFG-9000 appears in both of the expansions for Doom 3:
 * In Resurrection of Evil, the BFG is first available under the monorail tracks after returning to Phobos Labs after shutting down the life support systems. Though the Martian Buddy Blaster arcade game hints that this is a prize dropped off for you by Martian Buddy for getting a high score in the game, in reality the game only serves as a hint to the weapon's location, as it will still be there even if the arcade game is not played at all.
 * In The Lost Mission, the BFG is not available until Hell.

Trivia

 * The player can kill Campbell in Alpha Labs 1 to get his BFG, instead of waiting for Delta Labs 2A. It must be taken into account, though, that there is no ammunition anywhere until Delta Labs 2A.