Likewise the automatic and full attack actions mentioned upstream. I ready an action to shoot target A when it attacks, my action takes place after the trigger, which is when the attack is finished. That’s when the automatic fire has completed, or when all the attacks in a full attack have finished.
I quite agree with you, it's a solution I was defending as RAI, but everyone is against it.
Also it generates some silly cases. For example, if you have shot on the run, you can move, shoot, and get back behind a wall, and noone can ready an action to shoot at you as you end your move behind the wall. So, you can basically be untouchable and still shoot at people.It also forbids you to shoot at something "passing by" the window, for example.
And you can't shoot at someone approching you before he ends his move, so if the enemy has enough movement, he ends in melee range and you haven't had the opportunity to shoot at him without taking an AoO. Once again, it looks a bit weird considering the length of his movement.
So, there are many cases where you can't do things that are intuitively possible to everyone.
The same approach that would allow you to ready an attack for when someone "begins to cast" and interrupt a spell would allow you to ready an attack for when they "move their weapon toward you" and interrupt a shot.
Please don't misconstrue the discussion in this manner by associating something outside of the realm of the rules with something specifically part of the rules.
The reason we are talking about spells specifically is because in the spell casting section of the CRB it specifically states that spells can be interrupted by damage from a readied action.
As for the ready action and other triggering events which are part of another players actions, not related to spellcasting, I don't see the problem with the RAW.
I must agree with Claxon on his point about changing the wording to something more specific than triggering event. As it stand this has led to quite a bit of confusion and speculation.
I sit firmly in the camp of interpreting the RAW in the most favorable light as I can't realistically or intellectually discern the intent of the creators when trying to make an interpretation. I recognize my own hubris in attempting to do so and must try to abide with RAW until someone officially clears things up. I am actually going to open a post citing the examples from Xenocrat on the forums but also noting that these examples come prior to the official release and as a result are somewhat circumspect in their ruling.
Let's take the conversation on the readied action and spell casting to this new forum post as we have driven off course in answering the original posters question!
Thanks everyone for your input and feedback as I find your insights valuable.
So far the changes in suggested wording would not help. You're changing something to a synonym which means something to you individually but wouldn't necessarily have that same meaning to someone else.