Chainsaw/Doom 3

"Self powered chain-blade cutting tool. Part of a shipment incorrectly routed to the Mars dropship distribution center."

- PDA Description

The Chainsaw is a melee weapon, based on its classic iteration. They were items that were accidentally shipped to Mars by Mixom Corporation when the original order was for jackhammers. It is the game's most powerful melee weapon, first found in Service Room 2A of Communications Transfer, after the player gets ambushed by a pair of Sawyer Zombies who first make use of them against the player.

The chainsaw does not appear in Doom 3: Resurrection of Evil or in Doom 3: The Lost Mission, the bonus campaign featured in the Doom 3: BFG Edition package. It seems to have been replaced in these campaigns by the Grabber.

Weapon Schematics
Known commercially as Mixom's Beavertooth, the Chainsaw is powered by some kind of internal combustion engine (as seen by the smoke it generates). The player may aim it like most other weapons but it is only limited to melee combat. The length of the Beavertooth chainsaw is 30" according to the boxes the saws came in.

Tactical Analysis
As its only usage is limited to melee, the Chainsaw doesn't require any ammunition to function, hence being able to run indefinitely. However, it also takes a noticeable amount of time to rev up the chainsaw for usage, hence players may want to take this fact into consideration, particularly in close-quarters combat.

The chainsaw can be used, as a last ditch attempt, to survive when out of ammunition or as a means to dispatch Zombies, due to the fact the weapon has effectively infinite ammunition like its classic counterpart. It's also particularly effective against newly-spawned monsters like Imps (as they require a short amount of time to activate), Arch-viles (since they are vulnerable when summoning monsters), and Wraiths whilst teleporting. The Cacodemons' habit of flying toward the player also makes them vulnerable to being mowed. This weapon is also useful against riot-shield Zombies, as the blade can cut through their bulletproof shields.

Utilizing hit and run tactics is also recommended as the chainsaw deals massive damage once it hits the target, and is guaranteed to tear through enemies. Multiple strafing is advised against enemies with long range attack capabilities.

However, any enemies beyond that should be approached with caution. Usage on powerful enemies (such as Mancubi or Hell Knights) is not recommended as they will counter-attack the player, potentially causing heavy damage. The chainsaw is also not ideal for the smaller "pest" enemies like Lost Souls. If these conditions are unavoidable, it's wise to step back in line of the Lost Soul's attack pattern as it will go, without thought, directly straight into the player's weapon.

It should also be noted that the chainsaw's motor creates a large amount of noise while it's being wielded, which can prevent the player from hearing the noise cues generated by nearby enemies intended to warn the player of their presence. This can be circumvented by quick-switching to the chainsaw using the weapon's select key, rather than having it equipped while exploring.