MerricB said:
They may well consider it to be an "Attack of Opportunity triggered by Movement" - such would only trigger one AoO.
The rules do not limit you to "one AoO triggered by Movement".
They limit you to one AoO triggered by "
moving out of more than one square threatened by the same opponent in the same round".
The Hold the Line AoO is not provoked by moving out of a threatened square, but by moving into one. It
does not, as written, fall under the restriction, and is thus a separate opportunity.
That's why I said the wording was important. As written in Sword and Fist, it would require a special note if it were to fall under the restriction in 3.5. That note was not inserted.
If you take the AoO, you un-set your weapon and lose the Readied Action, because you can't very well be bracing it for the charge if you're waving at the approaching opponent.
You've given up a standard action for the sole purpose of gaining extra damage if your opponent charges. A Readied action does not occur until the triggering conditions are met.
As he enters the square, he provokes an AoO via Hold the Line.
Once he's in the square, your Readied Action triggers; you set your spear and get a double damage attack.
As he leaves the square, he provokes a movement AoO.
-Hyp.