Flashlight

"UAC Standard issue light source. This model utilizes a static transfer power supply, so battery replacement is unnecessary."

- PDA Description

The Flashlight is a tool and weapon in Doom 3, taking the appearance of a large red baton-like flashlight. It is the starting weapon the player obtains, alongside the Pistol.

Weapon schematics
The Flashlight is primarily used as a light source to illuminate dark areas. It runs through a static transfer power supply, thus allowing the player to utilize the flashlight indefinitely without the need to worry on battery depletion. The Flashlight can also be used as a club in close combat, dealing roughly twice as much damage as the player's fists. However, the range has reduced, and the attack rate is slower.

Tactical usage
On lower difficulties, the Flashlight can be used to attack Zombies to conserve ammo (two hits will kill them), provided if the player can constantly back away before the enemy can land a hit. Attacking an enemy stronger than an Imp is not recommended.

On higher difficulties, the Flashlight should only be used as a light source, as the damage from even a Zombie increases drastically. making it risky to even be using it as a melee weapon. The Flashlight could also be used to shine light on any "sleeping" Zombies to awaken them, distinguishing them from dead corpses. In deathmatch, using the Flashlight alerts other people to your whereabouts. The weapon is not included in the Xbox version's deathmatches.

Trivia

 * In response to the common criticisms players had about not being able to use the flashlight while using their weapon, the BFG Edition added a "mounted flashlight" on the Marine's armor as a replacement for the original flashlight. The new mounted flashlight only has a limited time period (roughly 30 seconds) to use before it has to recharge itself again. The world model for the red Flashlight still exists, although the player can't take it.