An (unofficial) explanation for why super mutants are in Fallout 76
Yes, Master.
A Fallout "lore nut" has attempted to explain why super mutants are in Fallout 76 when at first glance it seems like they shouldn't be.
Hot on the heels of the kerfuffle around a perceived retcon of The Brotherhood of Steel, which Bethesda has now explained in an official capacity, we have an unofficial explanation for why the super mutants are in Appalachia, Fallout's version of post-apocalyptic West Virginia circa 2102 - 25 years after the nuclear war that ruined the earth.
Ever since the Fallout 76 gameplay reveal in the summer, players have wondered whether the appearance of super mutants in West Virginia is consistent with Fallout lore. Prior to Fallout 76, the Fallout games had established super mutants in three areas: California, Washington D.C. and The Commonwealth (Boston). There was no mention of super mutants in West Virginia, and all previous Fallout games are set after Fallout 76. So, how did they get there?
The appropriately-named Vault took to Twitter to issue a thread that goes into detail on how and why this makes sense.
Vault points out that super mutants have existed on the east coast of America since 2078 "at the latest" - 24 years before Fallout 76.
Here's the background: the Forced Evolutionary Virus (FEV), the mutagen behind Fallout's famous super mutants, was sent to Vault 87 in Washington D.C. (as seen in Fallout 3) to allow research to continue in a sealed environment in the event of a nuclear war. The batch sent to D.C. led to a different strain of the virus than was used at the Mariposa Military Base in California on the west coast, and so is not linked to The Master, the antagonist of the first Fallout game.
According to Vault, the Vault 87 test subjects escaped in 2078, so there would have been plenty of time for super mutants who had established themselves in Washington D.C. to make their way to West Virginia by the time Fallout 76 kicks off in 2102.
As an aside, according to the Fallout timeline, the year Fallout 76 is happening, Richard Grey explores the abandoned Mariposa Military Base and is knocked into a vat of the virus, becoming The Master. The Master got on with his experiments on the west coast independent of events on the east coast. In short, Fallout 76 has nothing to do with The Master.
Questions, however, remain. Did the super mutants in Fallout 76 emerge from Vault 87 originally, or are they the result of an entirely new source of the virus?
Fallout 76 is out very soon, so hopefully an official explanation isn't far away.