AoO questions

[chaotician375]

What exactly can you do with an attack of opportunity. I know how they trigger, but what can you do with with one. I always thought that all you could do was attack, but last game my DM said that you could trip disarm and grapple with them. I'm looking for clarification on this and I can't find anything that says either way if you can or cannot. Either way, where, and what is, the answer?

[Diarmuid]

Any action that can normally take the place of an attack action can be used when an AoO is triggered.

Attack
Trip
Grapple
Disarm

Those are the usual suspects.

Edit- Realised you were looking for more "proof".

AoO Definition

Making an Attack of Opportunity: An attack of opportunity is a single melee attack...

Definition of some of the actions I specified.

DISARM
As a melee attack, you may attempt to disarm your opponent. /snip

Starting a Grapple
To start a grapple, you need to grab and hold your target. Starting a grapple requires a successful melee attack roll.

So basically any action that can be taken "as a melee attack" can be used in an AoO.

[SiuiS]

You can perform any attack action that is possible with one of our weapons, I believe.

Grappling, Disarming, Tripping and Non-lethal strikes are all still attacks. I think it gets sketchy if, say, you have a touch spell charged but provoke attacks because you're equipped with a dagger. Otherwise, anything that can be done as a single attack during a full attack routine can be done as an Attack of Opportunity.

A 20th level warrior type gets four attacks, at +20/+15/+10/+5, and he could do a no lethal attack with the first, a disarm with the second, a trip with the third, and a grapple with the last if he chose. So all of those would be attack actions.

[kulosle]

There are some feats that let you do more fun things with AoO, move 5ft(negates full round attacks), aid other checks, and i'm sure there are more but i can't recall at the moment. Also if dragon content is allowed then there are two feats that can let you make an additional attack for each AoO at -5 and -10. Its really worth it if you have the dexterity to have an absurd number of AoO.

[DarthCyberWolf]

I think it gets sketchy if, say, you have a touch spell charged but provoke attacks because you're equipped with a dagger.

I'm not sure, but don't you threaten if you have a touch spell charged? I'd certainly be wary if my opponent's hand was glowing with an as-yet unknown spell.

Though yes, I would make someone AoO with the dagger if that's how they're threatening.

[Gwendol]

I'm quite certain that you do threaten when holding the charge of a touch spell. Ah, yes: here's a quote from Rules of the Game (All about AoO's part 2): http://www.wizards.com/default.asp?x=dnd/rg/20041102a

You can use any special attack that you can use as a melee attack as an attack of opportunity. That includes disarming, grabbing someone to grapple, sunder, or trip. In the case of a trip attack, you must make the trip attack with whatever weapon you're using to threaten the area where you're making the attack of opportunity.

Though you cannot cast a spell as an attack of opportunity, you can use some spells as attacks of opportunity. If you're holding the charge from a touch spell, you can try to touch a foe as an attack of opportunity. Some spells last long enough to let you to make several melee attacks. Spells such as chill touch and produce flame prove useful for attacks of opportunity if someone provokes an attack of opportunity from you.