I'm a newbie to Pathfinder and the general D&D 3.x area, having only played a small number of sessions ever. Following a recent question I dove into the touch attack rules, since I realised I didn't know how they worked, having never seen them in use. What I have learned is: I have absolutely no idea how to even begin finding out how they work.
Combat: Touch Attacks says:
Some attacks completely disregard armor, including shields and natural armor—the aggressor need only touch a foe for such an attack to take full effect. In these cases, the attacker makes a touch attack roll (either ranged or melee).
No mention of how to make a touch attack roll, though. Range: Touch doesn't really explain anything at all. The Core Rulebook itself doesn't clarify anything in the spaces I've looked – there's nothing named 'touch attack' under the Attacks section in Combat, and the 'Touch spells in combat' thing doesn't explain much about the actual process involved.
For a moment I thought "hey, maybe touch attacks aren't actually a thing, since touch spells just discharge when you touch someone, so you can just make an unarmed attack and pow!" — then I read a comment within the above linked question:
An unarmed strike and a touch attack, while closely related, are different things (although one can combine the two).
So, I have no idea how someone makes a touch attack, and I have no idea how anyone knows how to make a touch attack, because I can find nothing on it beyond instructions to make one.
How do I make a touch attack? What's the actual process involved? What modifiers do I apply, if any?
And where, exactly, are the actual instructions on doing it?
Best Answer
A touch attack is a type of melee attack; you make it just the same as any other sort of melee attack. Effectively, it is a melee attack made using the charge of a touch-attack spell (or other ability) as your “weapon,” and with the benefit of ignoring armor, natural armor, and shield bonuses to AC.
An unarmed strike is another “effective weapon,” this time your fist or (for monks) other body part. You default to unarmed strikes when you are, ya know, unarmed, not using any other weapon. Since the charge of a touch attack is effectively a weapon, you do not default to using an unarmed strike for it.
However, you do have the option of discharging a touch attack with an unarmed strike. When you do this, you have to hit regular AC (i.e. including armor, natural armor, and shield bonuses), but you both hit with an unarmed strike, dealing the usual damage for that, and discharge the touch-attack charge on your target.
Note that while touch-attack charges are, in many ways, effectively weapons, they are not weapons. Unarmed strikes, on the other hand, are.1 This matters for all the things that boost “weapon damage,” like Inspire Courage.
1 though they exist in a weird quantum state combining the rules for manufactured and natural weapons