Touch Attack

[Leertes]

How, exactly, is touch attack calculated? From my understanding it side-steps some of the target's AC, but I was curious what the actual calculations were. Thanks for any answers.

[Hamlet]

Dexterity bonus, dodge and deflection modifier count against it.

[korak]

Do the following count also:

Natural Armor
Armor Skin
Expertise/Adv. Expertise

I have always wondered about those. It always seemed like I got hit less with those on, but it could be my imagination....which is pretty good.

[Leertes]

I understand that there are different variables that affect whether the touch-attack is a success or a failure, but I wanted to know the entire calculation. As in: 1d20 + Highest Attack Bonus + spell level vs. AC/2. Does anyone know the actual calculations?

[Pathos Street]

Do the following count also:

Natural Armor
Armor Skin
Expertise/Adv. Expertise

I have always wondered about those. It always seemed like I got hit less with those on, but it could be my imagination....which is pretty good.

Natural Armor - touch attack ignores. They only have to touch you, it doesn't matter how thick your skin is.
Armor Skin - "other" bonus, pretty sure it applies.
Expertise - I think this applies as well.

This is untested, of course.

[gwydion2]

I understand that there are different variables that affect whether the touch-attack is a success or a failure, but I wanted to know the entire calculation. As in: 1d20 + Highest Attack Bonus + spell level vs. AC/2. Does anyone know the actual calculations?

Basiclly if you want to know your touch attack AB just unequip your weapon and see what AB you have with bare hands. (Holding a +5 sword obviously won't help your touch attack)

Your target will have his ac reduced as follows :-
Ignore any natural armour bonus that comes from race or from spells (like barkskin) or items (such as amulets of natural armour)
Ignore any bonus from armour or shield (treat the enemy as naked with no shield equipped).

So for example, if your enemy had 35 ac, but that included +2 full plate (10 points of AC) A +1 tower shield (4 points of ac) and a +3 amulet of natural armour (3 points of ac).
His effective ac vs your touch attach would be 35-17=18

Unless your foes ac is almost exclusively dex/dodge/deflection based, he is going to be very much easier to hit.

[Kinarr]

Touch attack details from NWNWiki

http://nwn.wikia.com/wiki/Touch_attack

A touch attack denies the defender their armor and shield AC (base and bonus), as well as their natural armor bonus to AC. All other armor class modifiers, such as the size modifier, dexterity modifier, and deflection/dodge bonus (if any) apply normally.

The attacker uses their normal attack modifiers, excluding modifiers specific to whatever weapon is currently wielded. Note that as for regular attacks, the dexterity modifier is used for ranged touch attack rolls, not strength.