What would be the touch AC of a character with +5 chain mail, a +5 medium shield, a +5 ring of protection and 18 Dex? I just want to make sure I'm calculating this right.
P.S.: The above isn't a character or npc, just a sample.
That's exactly the issue a friend of mine and I are discussing... he beleives that you do keep the Armor Enhancement Bonus, I thought you didn't...
We're not really sure who is right.
The armor enhancement bonus is not separate from the armor. Its an enhancement to the AC that is provided by the armor. It isn't an enhancement to your AC.
On armor and shield the enhancement bonus is not a deflection bonus and so in no way relevant to the touch-AC. Only Deflection and Dodge Boni add to the Dexterity.
As far as I know the bonus on shields and armor is named enhancement bonus. So no deflection of blows and touches. Just some kind of ... hardened material or so.
So the AC (touch) is 10+4(Dex)+5(Deflection)
Dodge boni like from Mobility or Dodge would work, too.