Perception actually determines melee THC.

[LaserSaysPew]

Game says "Melee" skills does that, but it's false. I've got one character with 8 perception and 1 melee skill VS 3 perception and 5 melee skill. 95% THC vs 65% THC from the back.

[KnorKater]

Mhmm, still think there's something wrong with the THC itself too, cause I frequently miss even with 80-95% THC.

[ZombieBisque]

Thanks for the report.

[ZombieBisque]

No issue here, Melee properly determines melee THC; no other stat has any effect on it from the attacker. What you're likely experiencing is the Agility of your target, which will affect your THC. Different enemies also have different evasion values, so that would change your THC as well. When you attack the same enemy with different stats (for the attacker), the THC should be consistent. If not, let me know.