While every GM is free to define his world and his NPCs as he sees fit, the “default” setting of The Savage Soul (i.e., the aftermath of Yellow Mike and the Great Destruction) envisions a world where mutants are universally feared and hated by non-mutant humans.  As a result, when a character has any “Mutation” Peculiarity, it comes with the built-in disadvantage of widespread prejudice.  This is why Peculiarities such as “PW: Deceptive Appearance (1)” and “SP: Non-Mutant Augmentation” are valuable.

For each group of NPCs in his world, the GM must decide that group’s typical attitude toward mutants, which may range from murderous hostility to (in very rare cases) tolerance and acceptance.  A group like the Combine (Section 2.7.8), for example, is openly hostile toward all mutants and seeks to eradicate them.  This does not necessarily mean any given Combine member will mindlessly attack any mutant he sees (although he might); he will, however, likely refuse to associate with the mutant, subject the mutant to rude behavior, and seek opportunities to bring about the mutant’s eventual demise (possibly by reporting the mutant’s existence and whereabouts to Combine units better suited to engage with lethal force).

Most NPC groups (the average human settlement, for example) will not be quite so hostile toward mutants; but most (if not all) will genuinely believe one or more of the following:

• Mutants are dangerous and unpredictable and cannot be trusted.
• All mutants are secretly (if not openly) evil.
• All mutants secretly (if not openly) hate non-mutant humans.
• Mutants are unclean (or cursed) and exposure to mutants can cause disease or other maladies.

Keeping these deeply held beliefs in mind will help the GM decide how any given NPC would likely react to any given mutant.  For example: On an ordinary day, merchants, innkeepers, bartenders, and the like might refuse service to mutants, and townspeople might seek to drive mutants away.  In desperate times, however, these same proprietors and townspeople might grudgingly tolerate mutants that are willing to help solve problems . . . but be quick to fall back upon old prejudices once those problems are solved.

In any case, being a mutant should not be something a character can easily disregard.  And the GM should make a point of reminding such characters that, for them, few places in the world are truly friendly.