Readied Action vs. Attack of Opportunity

[skullboy]

I've seen a number of posts about the order of attacks between readied actions and attacks of opportunity, but I don't see one covering this situation.

A sorcerer is standing in a corridor next to a door (not at the door -- the next square over). He readies an action to cast a spell on the first thing that comes out the door.

A bad guy comes out the door. Who attacks first -- (a) the sorcerer with his readied action, or (b) the bad guy with his attack of opportunity vs. the spell-casting sorcerer? Any rule references would be appreciated.

Thanks.

[Cevah]

Bad guy comes through the door, triggering the readied action.
The action is casting a spell in melee, which provokes an Attack of Opportunity.
AoO gets resolved
If spell is a ranged spell, it provokes another AoO, which gets resolved first.
Readied action resolves
Bad guy move resolves

Smart sorcerer casts defensibly.

Smarter sorcerer readies the action cast+5'step for a melee spell or does not cast next to the door on a ranged spell.

/cevah

[Saldiven]

This is actually one of my preferred time paradoxes in Pathfinder.

"I ready an action to attack anyone opening that door.

Concerning readied actions, the CRB states:

"The action occurs just before the action that triggers it."

So, your attack takes place just before the person opens the door....?

There are lots of examples, but imprecise wording of a readied action will result in something happening before it could possibly happen (no line of effect or no ability to threaten the target, for example).

I figure most of us hand-wave this and handle it intuitively, but it's a funny interaction with the way the rule is written.

[Brother Fen]

Why would a spellcaster stand within range of being hit when he has enough time to ready an action. Your premise is faulty. If they're going to stand right next to the door and then not cast defensively, then yes, they get hit by an attack of opportunity first.

[UnArcaneElection]

^In some cases, you might not have anywhere else to stand/sit/float/whatever.