This is an unfinished idea. If your character has a stat, maybe they have a 1 in 6 chance to have a “quirk”. These quirks represents real life talents or biological quirks people have, and tying them to stats makes them reasonably rare and fitting to the character. Use only the character's highest/lowest/most extreme stat if they have a quirk and give them a Quirk for that.
: Some kind of Keloid scarring disorder. Any wound or injury has a good chance to form an abnormal amount of scar tissue. Probably shouldn't make a game element out of this, just what I feel fits good for a “quirk” for having strength.
-2 Strength: Some minor to severe scoliosis or spine misalignment.
+1 or +2 Strength: You can jump super high. Basketball player jump.
-1 or -2 Dex: Probably seizures of a minor kind.
+1 Dex: Double jointed in one body part. Just a quirk, not super useful.
+2 Dex: Partially ambidexterous. Can use weapons in both hands just fine.
-1 or -2 Int: Putting something here like development diseases or actual down syndrome would be a bit offensive and too crippling in a “realism” sense- and aspergers/autism is more of a social trait then a mental one in this context. Dyslexia would work just as well as a negative quirk. -1 Int just gives Dyslexia when in stressful situations but -2 is like permanent Dyslexia.
+1 Int: Photographic Memory?
+2 Int: No idea.
-1 Con: Sweaty?
-2 Con: Allergic to bees or something.. Will die without medical treatment after sting.
+2 Con: You've got that thing that makes lactic acid go away so you can basically run forever cross country if you wanted as long as you get enough food and sleep.
-1 Wis: Aphantasia, or you can't imagine things. Probably doesn't need to come up in a game but neither do any of these stupid ideas lmao.
-2 Wis: Colorblindness. Maybe only if you're male, unless you have -2 then you can have some more severe colorblindness or as a female. Colorblindness is more common in men but in weird fantasy genetics it could be totally different, especially for nonhuman races.
+1 or +2 Wis: Perfect pitch? Maybe unable to feel fear? I don't think that's a common medical thing though. Making people with High Wis sociopaths doesn't really fit even if it would make sense from a sort of “willpower” or “ignore fear” kind of thing, but I don't think so. Animal magnetism is more Cha so I'm unsure what to put here.
-1 Cha: Can't whistle.
-2 Cha: Insomnia. I know this could be in Int or Wis, but I like Cha because it gives you the bags under the eyes and makes you more irritable, and leads to moody behaviors and walking around at night because you can't sleep.
+2 Cha: Ok you can be Heterochromatic now.