At least they all sound male...but why? I don't really know of any super mutant backstory, such as how they were created (which may lead to an answer), but I never once heard a super mutant that sounded female when they spoke.


3 Answers 3


Not all super mutants are male.

Super Mutants are sterile. The nature of the FEV virus rewrites their genetic code from scratch, from exposure to particular strains of the virus -- mutants are NOT born, but rather they are recreated. The virus removes both primary and secondary sexual characteristics and leaves all the mutants sterile. Some mutants have male genitalia (seen by losing an arm wrestling match with Francis in FO2, then becoming his personal gimp for the night). Of course, this doesn't stop them from engaging in intercourse, but they are unable to breed.

The only two super mutants that attempt to pass off as female are Tabitha on Black Mountain and Lily from Jacobstown in FO:NV. Their voices, however, are not female, but rather attempting to emulate a female voice, similar to a male speaking in a falsetto tone.

Not all Super Mutants are male, it's just we haven't seen any female Super Mutants yet in any of the games to confirm this. East Coast super mutants seen in Fallout 3 and Fallout 4 lack genitalia, but the West Coast super mutants seen in Fallout 1 (not F:NV) could have genitalia (a few have it).


Actually the super mutant females are confirmed in Fallout 1 alongside the problem they can not breed. The strange thing is you never see a female super mutant or maybe you do see them but are unable to identify them.

To clear it up there will be some spoilers from Fallout 1 so you best stop reading if you intend to play it.

The last objective in Fallout 1 is to dispose of the leader of these super mutants. It is a strange mutant which seems to be an ex overseer hiding in his vault. When you meet him you start with a debate which if done right (includes some previous side quests) will lead to your victory without any battle.

It will explain that humans and super mutants don't go along and will battle each other until there is nothing left. That is why he established this cult and engaged the war between the 2 species, but he had to chose which side to join and he joined the mutants simply because they have a better chance of survival in this new world (what a great guy).

Now this leads to the situation where you may have a proof that super mutants simply lack the ability to breed (a quest). By showing him the proof he will then call his female super mutants to confirm that none of them are pregnant while expecting that some of them should be by now. Since it is such a good guy it is now in its conflict and sees it chose the wrong side. He proceeds by setting a countdown timer on a nuclear bomb in its possession. You run away and the whole cult is being destroyed.

  • Very good point, but since his females are never shown to us explicitly, while there is the assumption they exist we don't know if they have female genitalia at all
    – childe
    Commented Feb 4, 2017 at 19:20
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    That is true, there is nothing about their genitalia explicitly. Still they did seem to assume they would be able to breed so it might be safe to assume there was no obvious reason to think they will not be able to breed. And having no visible reproductive organs is an obvious reason to think otherwise. Commented Feb 4, 2017 at 19:25

Super Mutants were created through use of the Forced Evolutionary Virus (FEV for short). There have been several variation of the virus, but they all tend to leave those affected sterile, and without their secondary sexual characteristics (some strains of FEV remove all signs of pre-mutation gender).

The virus was originally designed to make humans immune to a wide variety diseases (among other things) by re-writing the genetic code. So while the virus is doing its thing, it sees the genetic code for the gender split as damage and... 'fixes' it.

There have been a few super mutants that identified as female (Tabitha and Lily from Fallout New Vegas). It is difficult to tell how many super mutants might have been female before mutation, as the games tend to not show us their genitals (assuming their particular strain of the virus kept those). So it is really only the super mutants who remain intelligent (somewhat rare) and aware of their past life (even rarer) who can express their old gender.

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    Consider it is not necessarily up to super-mutants to self-identify themselves as female, since as you mentioned Tabitha and Lily try to pass off as one, but as humans playing the game and playing as a human character it's not entirely difficult to classify the difference between male and female, even that far into the post-apocalypse
    – childe
    Commented Feb 4, 2017 at 8:20
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    Ordinarily I would agree - but presence of genitals between the legs of the west-coast variants aside; The FEV paints all super mutants with the same secondary sexual characteristic brush. We may associate big mountains of muscle and a deep voice as male, but it doesn't apply to super mutants. The visual cues we look for among (non-mutated) humans are simply not there. And the visual cues that you MIGHT be able to see on the west-coasters - unless you're a protagonist or the heavens have set your essential rating to 1, you probably aren't gonna survive getting close enough to check. Commented Feb 4, 2017 at 9:09
  • Just a pedantic thought here, but technically speaking wouldn't the gender split being considered "damage to be repaired" mean that the Y chromosome is "repaired" into a second X, resulting in an all-female Super Mutant population? :D Commented Feb 4, 2017 at 14:30

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