How do I make a touch attack?

Question

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?

Answer 1

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

Answer 2

You use the general rule, except where a more specific rule changes it.

Touch attacks say this:

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). When you are the target of a touch attack, your AC doesn't include any armor bonus, shield bonus, or natural armor bonus. All other modifiers, such as your size modifier, Dexterity modifier, and deflection bonus (if any) apply normally. Some creatures have the ability to make incorporeal touch attacks. These attacks bypass solid objects, such as armor and shields, by passing through them. Incorporeal touch attacks work similarly to normal touch attacks except that they also ignore cover bonuses. Incorporeal touch attacks do not ignore armor bonuses granted by force effects, such as mage armor and bracers of armor.

So a touch attack is an Attack:

An attack roll represents your attempt to strike your opponent on your turn in a round. When you make an attack roll, you roll a d20 and add your attack bonus. (Other modifiers may also apply to this roll.) If your result equals or beats the target's Armor Class, you hit and deal damage.

Your attack bonus is BAB + strength modifier + size modifier.

You're trying to hit AC, without the things listed in touch attacks (no armor, shield, or natural armor bonus). That's generally called Touch AC.

Touch attacks do not do weapon damage. All you're doing is touching. If you are trying to attack to inflict weapon damage, it's a normal attack and not a touch attack.

Alternatively, you may make a normal unarmed attack (or an attack with a natural weapon) while holding a charge. In this case, you aren't considered armed and you provoke attacks of opportunity as normal for the attack. If your unarmed attack or natural weapon attack normally doesn't provoke attacks of opportunity, neither does this attack. If the attack hits, you deal normal damage for your unarmed attack or natural weapon and the spell discharges. If the attack misses, you are still holding the charge.

So, you can do a touch attack to inflict the spell (and not do weapon damage), or you can use a normal unarmed strike (and do weapon damage). In either cases, if you hit, the touch spell effect occurs.

Answer 3

A very simple version of the answer:

A Touch Attack is a melee attack that does no inherent damage. You only have to touch them or their armor. Their armor doesn't matter, because touching their armor counts as touching them. You're not trying to hurt them with the touch. Just with what spell the touch discharges.

An Unarmed Attack is a melee attack that is trying to do damage. Armor matters, because you're trying to punch (kick,bite,claw,slap) them, and if you punch (kick,bite,claw,slap) them in the breastplate they won't get hurt. You are trying to hurt them with your fist.

If you do both at once, you are trying to hurt them with your fist AND with the discharging spell.

Mechanically, these are the same thing until it gets to the AC that they have to overcome, and whether or not the attack has the potential to deal normal, physical damage.

http://www.d20pfsrd.com/gamemastering/combat#TOC-Touch-Attacks