Plasma rifle

Plasma rifles or plasma casters are energy based weapons that appear in Fallout, Fallout 2, Fallout 3, Fallout: New Vegas, Fallout 4, Fallout 76, Fallout Tactics, Fallout: Brotherhood of Steel, Fallout Shelter and Fallout: The Board Game.

Background
 Plasma rifles or plasma casters are high tech weapons firing superheated bolts of plasma, powered by either microfusion cells, heavy energy cells, Plasma cartridge (Fallout 4)s, or Plasma cores which find numerous applications in military and industrial fields. The bolts form into toroids in the plasma chamber, which are then sent down a superconducting barrel,  propelled by, and in some models stabilized by, electromagnetic claws upon exiting it. However, the plasma bolt chamber can be hotwired in order to accelerate the bolt formation process, effectively turbocharging the rifle. The primary damage mechanism of plasma rifles is thermal transfer, causing serious burns to soft targets and melting hard ones. In extreme cases, the plasma can cause spontaneous dissolution of the target, including separation of soft tissues from hard ones or wholesale molecular destabilization that turns the target into a viscous green fluid.

Initially, the weapon was a bulky, industrial plasma caster, manufactured by Winchester Arms; while it performed admirably, it was expensive and required specialized training to use. However, later developments for the United States Army would lead to a more compact design that was cheaper to produce and easier to train for, perfectly suited for urban warfare. 

Winchester P94


 The Winchester Model P94 is a bulky, industrial-grade energy caster, firing superheated bolts of plasma down a superconducting barrel, ending in electromagnetic claws helping to stabilize the plasma bolt. In an interview for Future Weapons Today, United States Army Colonel Moretti slammed the design, likely for being bulky and outdated. This would lead to corporations like REPCONN Aerospace and Poseidon Energy undertaking projects intended to replace the P94. 
 * For the modified version that appears in Fallout and Fallout 2, see Turbo plasma rifle.
 * For the unique P94 plasma caster in Fallout: New Vegas, see The Smitty Special.
 * For the modification that appears in Fallout: New Vegas, see Plasma caster HS electrode.

Winchester P94 military
In the military version, the company has downsized the weapon and revamped its design, making it a more portable energy rifle, complete with a stock, pistol grip and carry handle which can, presumably, also mount optics.

Urban plasma rifle


This plasma rifle is a lightweight urban warfare weapon created as part of a desire to replace the aging Winchester P94 "Plasma Caster" design. This design was produced and fielded in number prior to the Great War of October 23, 2077. This however was not the end of the design nor manufacture of this weapon platform. Prior to the nuclear Armageddon, REPCONN Aerospace (as a subsidiary of RobCo Industries) would successfully develop an improvement from their spaceflight research. With significantly advanced factions tinkering with the design post Armageddon. 

This rifle uses a microfusion cell as its power source and draws plasma from a separate cartridge. When depressing the trigger, a plasma toroid is produced that can remain stable under normal atmospheric conditions. This toroid is then ejected down a superconducting barrel against a given target. The rifles are highly modifiable, able to be converted into a pistol with ease, and potentially turned into a designated sniper rifle, flamethrower, scatter gun, and even an automatic rifle by simply swapping out the barrels. 
 * For the unique plasma rifle in Fallout 3, see A3-21's plasma rifle.
 * For the unique plasma rifle in Fallout: New Vegas, see Q-35 matter modulator.
 * For a unique plasma rifle in Fallout 4, see Experiment 18-A.
 * For a unique plasma rifle in Fallout 4, see Sentinel's Plasmacaster.
 * For the Legendary weapon in Fallout Shelter, see Mean Green Monster.
 * For the cut content plasma rifle in Fallout: New Vegas, see Plasma rifle always crit and Plasma rifle weak.

V.32 Quantum plasma modulation matter injection rifle
Version: 32

Status: Failure

Notes: While v.32 didn't have the power yield of the v.31 or v.30, we managed to increase the stabilization threshold by approximately 27.35%. This is promising, however we still have yet to come up with a solution for the matter inversion issues.

V.33 Quantum plasma modulation matter injection rifle
Version: 33

Status: Failure

Notes: Lab destroyed. Data Lost.

V.34 Quantum plasma modulation matter injection rifle
Version: 34

Status: Failure

Notes: Interesting. I'm not sure where we got this data from, it is a completely different direction from what we've been working on. We managed to cycle the matter inversion using a polarized quantum spin. I think that we solved the issue with the Compensation field, I have high hopes for the next weapon.

V.35 Quantum plasma modulation matter injection rifle


 Also known as the Q-35 matter modulator, the V.35 quantum plasma modulation matter injection rifle was created by REPCONN Aerospace engineers as part of the Quantum Plasma Modulation Matter Injection Rifle project, a research program overseen by Colonel Moretti of the United States Army, who was looking for a replacement for the aging plasma rifle designs, especially the Winchester P94.

The prototype was created by a team of engineers under the lead of Senior Staff Engineer Xuan Duong, using design specifications stolen from Poseidon Energy for the canceled plasma rifle project Semele, in conjunction with designs from their own plasma engine, the failed quantum matter modulator of the Z43-521P rocket. Poseidon data allowed the REPCONN team to rectify issues with matter inversion by using a polarized quantum spin, simultaneously solving the issues with matter conversion in the Heisenberg compensation field, enabling the creation of the first prototype of a new line of plasma weapons.

With the data from the SEMELE project, REPCONN was finally able to create a functional prototype after thirty-four failures. While prototype materials make it unsuitable for prolonged field use, the Q-35 has a longer refire rate on average, but a more consistent delay between shots, an increase in active bolt charge time, increased accuracy and a 30% increase in bolt energy.

When the prototype was completed, unknown individuals conspired with REPCONN's CFO, Julia Masters, to intercept and secure the prototype while it was in transit to the Department of Defense. 

Multiplas rifle


 The multiplas rifle (a portmanteau of "multiple" and "plasma") is based on the urban plasma rifle design. It is a sort of "plasma shotgun," firing three rounds of plasma in a volley, at the cost of a massive drain on the microfusion cell.

Electric plasma rifle


 The electric plasma rifle only appears in the city of Los and the Secret Vault. It's to be manufactured using technology contained in the Secret Vault. It's equipped by the most important ghouls of the Church of the Lost and some super mutants of Attis' army.

Turbo electric plasma rifle


 The turbo electric plasma rifle is an upgraded version of the electric plasma rifle, and is only found in the Secret Vault. It's to be manufactured using technology contained in the Secret Vault. It's equipped by the most important super mutants of Attis' army and by the champion of the Gladiator Pit in Los, the wasteland stranger.

Behind the scenes
According to the Fallout demo, the P94 plasma rifle's item name was originally going to be called "Plasma Caster."