Starting a full-round action then becoming staggered

[EvilMinion]

So how does one adjudicate the following:

NPC starts a coup de grace action on fallen opponent while threatened, thus provoking an attack of opportunity.

PC hits NPC with their AOO, taking the NPC to exactly 0 hp's, thus NPC is now staggered.

Can the NPC complete their coup de grace action this turn? next turn? at all?

Similar sort of situation could come up if a character charges.

[BobtheSamurai]

IIRC, AoO happens before the triggering action, except in special cases. So, the coup de grace would be prevented, but a charge might still be possible depending on the distance already traveled.

[Claxon]

Quote:

A staggered creature may take a single move action or standard action each round (but not both, nor can he take full-round actions). A staggered creature can still take free, swift, and immediate actions. A creature with nonlethal damage exactly equal to its current hit points gains the staggered condition.

Quote:

The "start full-round action" standard action lets you start undertaking a full-round action, which you can complete in the following round by using another standard action. You can't use this action to start or complete a full attack, charge, run, or withdraw.

So, based on this I would say the NPC can complete the coup de grace because he can start is as a standard action and finish it as a standard action on his next turn.