The wastelands of the Fallout universe are full of many weird and mutated creatures resulting from the radiation leftover from the Great War. Super mutants, however, weren't created by radiation - so what did?

Super mutants have existed since the very first Fallout game, and have appeared in every game in the franchise. Although these humanoids have a reputation for not being particularly intelligent, they are capable of organizing in groups and wielding any advanced weapons they come across. Super mutants are incredibly strong and resistant to disease and radiation. They frequently raid human settlements and have even coordinated larger attacks against humans in order to control an area.

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The first existing super mutants of Fallout originated on the west coast. They are the result of humans being exposed to a chemical known as the Forced Evolutionary Virus (FEV). The FEV was developed at the Mariposa Military Base in California as a way to create super soldiers. An expedition to the Mariposa Military Base after the Great War discovered the virus, and the sole survivor of the expedition, Richard Grey, was accidentally exposed to the virus. His mind warped by his mutation, Grey became determined to infect humans with the FEV and create a world of super mutants. His efforts are eventually stopped by players in the first Fallout game, but by then, Grey had infected a sizeable number of people with the FEV. Super mutants became a permanent fixture of wasteland life.

How Super Mutants Got to Fallout's East Coast

Fallout 3 Capital Wasteland

Although super mutants were a west coast creation, the FEV made its way to the east coast through distribution to other research locations, eventually creating three major super mutant groups. Vault 87 super mutants came from a modified version of FEV used in the vault as part of the Evolutionary Experimentation Program. The super mutants of Fallout 76, meanwhile, were created when company West Tek dumped FEV into the local drinking water of the town of Huntersville, West Virginia. The last (and largest) major enclave of super mutants was created by experiments done by the Institute as part of the faction's work to create synths.

Perhaps most horrifyingly, the FEV renders super mutants infertile, meaning that the only way to create more super mutants is to expose humans to FEV. This has sometimes resulted in super mutants capturing humans and forcibly injecting them with FEV. Safe to say, most normal humans wandering the wastelands of the Fallout universe should avoid super mutants at all costs.

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