The Gauss rifle, also called a "coil gun," is a device used to propel a ferromagnetic projectile by accelerating it through a process of magnet induction. The Gauss rifle (and Gauss gun) are named after German mathematician Carl Friedrich Gauss, who formulated mathematical descriptions of the magnetic effect demonstrated by magnetic accelerators.
This rifle uses a series of electromagnetic fields to propel 2mm rounds at tremendous speed. It has a knockdown effect that will knock enemies off their feet following a Critical Hit.
Unlike the German M72 Gauss rifle, which uses 2mm EC magazines containing both batteries and ammunition, this gun requires the user to load in the microfusion cells needed to magnetize each pre-loaded round contained in the magazine attached to the side of the weapon. Each round produces a small "explosion" on impact, dealing minor splash damage.
The Gauss rifle has greater reliability per shot than the Victory Rifle for knocking down enemies, but its buggy V.A.T.S. performance and low magazine size limits its usefulness in close-quarters combat.
Sim version (Operation: Anchorageadd-on) - A sim-only version of the weapon which differs only in health (essentially non-degrading).
The following is based on Fallout 3 cut content and has not been confirmed by canon sources.
Gauss rifle - There is a beta version of the Gauss rifle that uses the model of a laser rifle and features a five round magazine. It does only about 25% of the damage of the final version, but has a 100% knockdown chance. It is only obtainable through console commands.
End of information based on Fallout 3 cut content.
The Gauss rifle is one of the few Energy Weapons that doesn't disintegrate the target when they are killed with a Critical Hit.
Even though it does have a very large 2mm round magazine located on the right of the gun, no matter how many shots are fired, it never needs to be replaced or reloaded. Only the microfusion cells used to charge the 2mm rounds need to be reloaded.
Although quite a powerful ranged rifle, its firing and reload times are extremely time consuming.
You can only obtain this weapon once without glitches, so you can only repair it with Alien epoxy (Mothership Zeta add-on) or ask an NPC to do the repairs.
If you have the Finesse perk, nearly every shot you fire (V.A.T.S. or not) will score critical. This is useful against enemies like super mutant overlords, feral ghoul reavers, Enclave Hellfire troopers, albino radscorpions, or aliens. This is also an ideal way to take out super mutant behemoths as the high damage combined with the knockdown effect makes it more useful than even the Victory Rifle since the high damage means fewer shots are required to kill.
If the player were to shoot an enemy's weapon and break it with a critical hit, the enemy will go flying several feet without taking any fall damage.
Although Gauss rifles are seen on Chinese propaganda posters throughout the Anchorage simulation, none of the Chinese soldiers carried one.
pcps3xbox360 The scope on the Gauss rifle, like on the sniper rifle, is not perfectly zeroed. The shot will travel up and to the right of the target at extreme distances. [verified]
pcps3xbox360 Occasionally, shots dealt from the Gauss rifle will not do damage, regardless of the type of hit it was (crippling hit, critical strike, sneak attack critical). However, it can still knock down enemies and cripple them. [verified]
pcps3xbox360 This weapon does not deal proper damage when in V.A.T.S. Any hit will do exactly 95.244% of the maximum damage, regardless of enemy DR, critical hits, or sneak attacks. This means that, with 100 energy weapons, a Gauss rifle shot will do 95.244 points of damage with every V.A.T.S. shot. This is still lower than free aiming, and no bonuses are applied to headshots. [verified]
pcps3xbox360 If your character is knocked down, either by a gas explosion or a frag grenade, the Gauss rifle may go flying. It will stay wherever it lands, and pulling the trigger will cause the rifle to fire from wherever it landed. This can also be achieved if the impact of the rifle's shots are too close and knock the weapon out of your character's hands. Holstering the weapon has no effect. Equipping another weapon will fix the issue. [verified]
pcps3xbox360 If you have any type of power armor equipped at the same time the rifle is equipped, the air tanks and valve on the armor will disappear. This is because it has the "hide backpack" flag marked, despite not having a backpack component like other weapons with this flag (minigun, Gatling laser, etc.). [verified]
pcps3xbox360 Critical shots to the target's weapon will still knock them down. [verified]
pcps3xbox360 Critical shots that do not kill will occasionally cause the target to fall through the map. [verified]
xbox360 Sometimes in V.A.T.S when firing there will be a slight delay for firing but the firing sound will be normal, like when you reload and the sound for reloading is already done. [verified]
xbox360ps3 Sometimes if you fire the Gauss rifle straight down when standing, the camera will be switched to third person and the rifle will be knocked out of your hands until the reload animation finishes. It usually takes more than one shot since it doesn't always do damage. [verified]
↑We did it this way because we knew we wanted to have an energy weapon equivalent of the sniper rifle, but also have it be consistent with other fictional versions of the Gauss rifle, including the one known in the Fallout universe. We also knew it had to use and existing ammunition type, since the player was going to get access to the Gauss rifle in the Wasteland, and would need to be able to find ammunition for it. It didn't feel right using the sniper rifle ammunition (we had considered it), and instead opted to "power" the weapon with the microfusion cell, but (fictionally) have it fire a standard slug, which is already pre-loaded into the weapon. - Emil Pagliarulo in the Bethesda Game Studios forum