Super Mutants: Where Fallout's Hulking Green Mutants Come From

Super mutants are humans who have been changed by the Forced Evolutionary Virus, or FEV, into huge, green-skinned, heavily muscled mutants that shrug off disease and radiation. They can't have children. They first appeared in the original Fallout as the army of the Master, and every main game since has had its own strain, made at a different lab from a different version of the virus. (Fallout; Fallout 3; Fallout 4)

How are super mutants made?#

A super mutant is a human soaked in FEV. The virus rewrites the body, adding size, strength and toughness and making the subject immune to most disease and radiation. The cost is fertility, and often intelligence: how bright a mutant ends up depends on the strain and on how healthy the person was going in. (Fallout; Fallout: New Vegas)

The research started before the war. Files at Mariposa Military Base show the FEV project moving there from West Tek, and the experiments on prisoners that followed. In the TV series, one of the executives at a secret Vault-Tec meeting suggests using a Vault to develop "a super-mutant soldier". (Fallout; Fallout, "The Beginning")

The Master's army#

The first super mutants came from Mariposa after the war. Richard Grey, a doctor on an expedition to the base, fell into a vat of FEV and emerged fused into a single mass of flesh. As the Master, he sent his mutants to kidnap travellers and dip them in the vats, aiming to turn all of humanity into one new race and end the differences that caused the war. (Fallout)

He called his army the Unity and ran a front religion, the Children of the Cathedral, in Los Angeles. In 2162 the Vault Dweller destroyed both him and the vats. One way to stop him is to show him that his mutants are sterile, so the Unity could never replace mankind. (Fallout)

Super mutants after the Master#

Not all of the Unity's survivors stayed hostile. In Fallout 2, the super mutant Marcus is sheriff of Broken Hills, a mining town where humans, mutants and ghouls live together, and he can join the Chosen One. The Enclave reopens Mariposa to get at its FEV. (Fallout 2)

By New Vegas in 2281, Marcus runs Jacobstown, a mountain retreat for mutants. The Nightkin, the Master's elite stealth troops, live there and at Black Mountain, their minds damaged by years of using Stealth Boys. New Vegas also explains that a second, less intelligent generation formed when the Enclave's slave miners were exposed to leftover FEV at Mariposa. (Fallout: New Vegas)

Vault 87 and the Capital Wasteland#

The super mutants of Fallout 3 come from Vault 87, where Vault-Tec tested its own strain on the residents. They are almost all hostile, barely speak, and keep growing as they age until the oldest become behemoths. They pour out of the Vault to raid Washington, DC, and the Brotherhood of Steel has been fighting them for years. The Lone Wanderer has to go into Vault 87 itself. Fawkes, a mutant held there, is one of the few friendly ones and helps the Wanderer get through. (Fallout 3)

The Institute strain#

In Fallout 4 the Institute made its own super mutants while experimenting with FEV on people abducted from the Commonwealth, then dumped them on the surface. They form tribes, see humans as weak, and are among the most common enemies in Boston. Strong, a companion, is one of them. Brian Virgil, a former Institute scientist, makes a serum that turns him back into a human, the only known cure. (Fallout 4)

West Tek and Appalachia#

Fallout 76 takes the story back to 2102 in West Virginia. There, super mutants come from West Tek's research centre, from the exposure of the town of Huntersville to FEV, and from Enclave experiments on survivors. They are as aggressive as the Commonwealth strain and look much the same. (Fallout 76)

Super mutants in the Fallout TV series#

Season 1 shows a large green hand on a gurney at the Enclave's research colony, the first hint that the Enclave is working with FEV. In season 2, after the Ghoul is impaled on a pole in Freeside, a super mutant pulls him free, treats him with uranium and takes him to its hideout. It says the Enclave calls mutants abominations but "created our kind", that ghouls and mutants are kin, and that war is coming against "the people who set all this in motion". The Ghoul refuses to join, so the mutant knocks him out and dumps him somewhere else. (Fallout, "The Target"; Fallout, "The Other Player")