How do those correlate? If I have a bonus to touch AC - does it improve my overall AC?
If it doesn't - what if I get touch AC that is higher than overall AC?
Touch AC is affected by the same things as regular. It is your regular AC, minus armor bonuses, shield bonuses, and natural armor bonuses. It will be less than your regular AC 99% of the time (barring corner-case feats, traits, etc.). If you get a bonus to it specifically, then no, it wouldn't boost regular AC, but since things that boost touch AC usually affect regular, both tend to do up at the same time. There's nothing saying it can't be higher than regular AC at all, just that mathematically, it's very rare.
If you get a bonus to it specifically, then no, it wouldn't boost regular AC
But I still will use my touch AC, which is higher, against touch attacks?
Touch AC is always vs "Touch" attacks.
If somehow, your Touch AC is higher than your usual AC (I don't even really know how that's possible usually, but, whatever), then you are somehow magically harder to touch than specifically to hit.
Case in point, if you are completely unarmored, your AC and TAC are both equal to 10 + Dex. Your FFAC is equal to just your Dex (since you have no armor on). If you have a magical item that gives a +3 to Touch AC SPECIFICALLY, your AC = 10 + Dex, your TAC = 10 + Dex + 3.
It doesn't make ANY sense, but mechanically there it is.
Anyway, attacks that don't mention that they are Touch always go against your normal AC (unless, you are flat-footed).
Ranged Touch Attacks, normal Touch Attacks, etc. all use your TAC to hit.
Even if your TAC is higher, you do not use your TAC vs normal attacks.
Touch AC is always vs "Touch" attacks.
If somehow, your Touch AC is higher than your usual AC (I don't even really know how that's possible usually, but, whatever), then you are somehow magically harder to touch than specifically to hit.
Case in point, if you are completely unarmored, your AC and TAC are both equal to 10 + Dex. Your FFAC is equal to just your Dex (since you have no armor on). If you have a magical item that gives a +3 to Touch AC SPECIFICALLY, your AC = 10 + Dex, your TAC = 10 + Dex + 3.
It doesn't make ANY sense, but mechanically there it is.
Anyway, attacks that don't mention that they are Touch always go against your normal AC (unless, you are flat-footed).
Ranged Touch Attacks, normal Touch Attacks, etc. all use your TAC to hit.
Even if your TAC is higher, you do not use your TAC vs normal attacks.
Bolded above is wrong, Sorry.
AC = 10 + Dex Mod + Armor + Natural Armor (everyone has +0 if no other NAC listed) + Shield + Deflection + Dodge + Sacred + Profane + Luck + Untyped
Touch AC = 10 + Dex Mod + Deflection + Dodge + Sacred + Profane + Luck + Untyped
Flat Foot = 10 + Armor + Natural Armor + Deflection + Sacred + Profane + Luck + Untyped
There are a couple of corner cases (Trait Bonus from a trait that adds +1 to your Armor AC if you wear Medium or higher armor
In general, unless you have a ring of deflection or unusual bonus, your flat foot touch AC is 10 (Base 10 + no bonuses).
Flat Foot = 10 + Armor + Natural Armor + Deflection + Sacred + Profane + Luck + Untyped
Don't forget that you also add your shield bonus to FFAC.
As for having a Touch AC higher than your normal AC, it should function just like normal, and you would use your likely higher than average touch AC against touch attacks and your normal AC against most other attacks.
Bolded above is wrong, Sorry.
Meant to say "everything BUT your dex" - must've deleted too much.
Having a Touch AC that's higher than your normal AC is just... weird.
I mean, having a Touch AC higher than Flat Footed is pretty easy to do, but Touch being greater than normal is... really, REALLY abnormal.
Obviously, mechanically, it works, and your TAC and normal AC are two different things and are used for two different types of attacks, but normal AC is, be design, SUPPOSED to be higher than both TAC and FFAC.
Anyway, that's a real fringe thing, and not something you should really worry about HOW something like that is possible, and just know that:
non-Touch Attacks use normal AC.
Touch Attacks use Touch AC
non-Touch Attacks use FFAC when you are caught Flat-Footed or denied your Dexterity Bonus to AC for whatever reasons.
Flat Foot = 10 + Armor + Natural Armor + Deflection + Sacred + Profane + Luck + UntypedDon't forget that you also add your shield bonus to FFAC.
As for having a Touch AC higher than your normal AC, it should function just like normal, and you would use your likely higher than average touch AC against touch attacks and your normal AC against most other attacks.
Meh, yeah, left that out, sorry.
Probably a freudian slip. I've always thought Shield AC is an active defense, so flat footedness should affect it (except for tower shields! LOL).
A Barbarian with the Ghost Rager Rage Power can in fact have a higher Touch AC than Regular AC.
Think that's about the only example, though.