Preventing a coup de grace with an attack of opportunity

Question

We recently had a situation where an enemy red mantis assassin was using his death attack on another player's character. (He first fascinates the target and can make a coup de grace later).

My pc noticed the assassin the round before he did the coup de grace and charged him, dealing some damage. His making the coup de grace provoked an attack of opportunity but it was sure that the enemy still had too many hp left to defeat him by dealing damage.

In the end I decided to disarm him, which worked but did not help because he was wielding two weapons and thus still had one he could use for the coup de grace.

I assume that a trip would not have stopped it either because the coup de grace is an automatic hit and all being prone does is give a penalty to hit.

Is there anything I missed that can be done as an AoO, without needing a special feat, that could stop a coup de grace?

Answer 1

Bull Rush

Normally a bull rush can only be attempted as a standard action or as part of a charge action.

You can make a bull rush as a standard action or as part of a charge, in place of the melee attack.

But there are abilities and feats that let you bull rush an opponent as part of a melee attack, like the Shield Slam feat. This means you could use bull rush as part of an attack of opportunity if you attacked with your shield.

If the target was bull rushed away and you didn't move with him, you would be out of his reach and his attack would fail.

Disarm

Disarm uses an attack action with a held weapon, thus it can be used with an attack of opportunity, similar to a bull rush.

Even if he had another weapon, he cannot replace the weapon he declared on his action, you interrupted his action after he declared it, so it was interrupted and he would have to spend another full-round action with his other weapon.

Condition that remove the ability to act

Such as Nauseated (Nauseated creatures are unable to attack), Paralyzed (A paralyzed character is frozen in place and unable to move or act.), Staggered (A staggered creature may take a single move action or standard action each round), or Stunned (A stunned creature drops everything held, can’t take actions).

This can be done with certain feats or class abilities, such as Stunning Fist.

You could kill him

If you deal enough damage so he goes unconcious or death, his action is simply interrupted and his coup-de-grace fails.

Draw a weapon

The Fascinated condition has another way to prevent this special attack:

Any obvious threat, such as someone drawing a weapon, casting a spell, or aiming a ranged weapon at the fascinated creature, automatically breaks the effect.

If the target is no longer fascinated, she can no longer make a coup de grace.

At any point after 3 rounds, she may make a coup de grace attack against the target, provided the target is still fascinated.