What is FEV in Fallout Season 2?

Fallout Season 2 is giving the live-action treatment to many elements from the franchise. We’ve already seen creatures such as Radscorpions and Deathclaws in the show, although there’s another important mutated race that’s yet to make an appearance. We’re, of course, referring to Super Mutants, who haven’t yet featured in Amazon Prime’s web series.

With that being said, episode five appears to be hinting at their arrival by introducing audiences to F.E.V., or the Forced Evolutionary Virus. In the show, Norm discovers a terminal carrying a brief description of the virus, before he is rudely interrupted by Vault 31’s Ronnie. The show will likely reveal the details in future episodes, but you’re interested in finding them out right now, here’s what you need to know about FEV. in Fallout.

Fallout Forced Evolutionary Virus (FEV) Explained

In Fallout’s expansive lore, F.E.V. (Forced Evolutionary Virus) was developed by the West Tek Corporation, the biggest pre-war defense contractor for the United States. The virus was intended as a bioweapon capable of forcing mutations on subjects, leaving them entirely unrecognisable in the process. The virus can be modified quite easily, which is why different strains of FEV were developed to meet different objectives.

No matter the strain, exposure to FEV almost always causes extreme pain and distress as it quite literally rewrites parts of its host’s DNA. The virus was at the center of Fallout 1’s narrative, as the game’s antagonist – the Master – uses the FEV-2 strain to create a new race to replace humanity. He dubbed his creations ‘Super Mutants,’ whose mutations give them a better-chance of surviving the nuclear wasteland. FEV is also responsible for monstrosities such as Centaurs and Floaters, but it is primarily linked to the creation of Super Mutants.

In episode five, the virus is described as a “gene-altering agent” capable of organism supercharging. This definition lines up with what we see in the games, as FEV can have a regenerative effect while also accelerating mutations, theoretically creating “a better version” of its subject. Unfortunately, this often comes at the cost of organ failure, body deformation, and mental damage.

What Role Does FEV Play in Fallout Season 2?

As of episode five, it’s unclear exactly what the FEV reveal could be building towards. That said, it seems increasingly likely that we’ll see a Super Mutant in future episodes. The Season 2 trailer strongly hinted at this via a scene featuring a hooded figure, whose deep, guttural voice matches up with what Super Mutants sound like in the games.

With all that said, it’s hard to say what narrative implications the introduction of Super Mutants could carry. The series has already established the Enclave and the Brotherhood of Steel (two factions that detest Super Mutants), so perhaps it could set up some sort of Mutant rebellion? Or maybe it’s just hinting at one of Vault-Tec’s inhumane experiments involving FEV exposure? The only way to find out is by waiting for the next episodes.

And that is everything you need to know about FEV in Fallout. What are your thoughts on Season 2 so far? Let us know in the comments.