Does Backswing apply to attacks of opportunity provoked during a full attack?

Question

The Two-Handed Fighter archetype has the ability:

Backswing (Ex)

At 7th level, when a two-handed fighter makes a full-attack with a two-handed weapon, he adds double his Strength bonus on damage rolls for all attacks after the first.

The fighter I'm building has a trip focus so, in a full attack, I can use my first attack to trip and all subsequent attacks will have double str bonus against a prone enemy. However Greater Trip allows me to take an AoO after a successful trip and, combat reflexes and the fortuitous weapon special would allow me to take 2 AoOs against this target that I tripped.

So since these AoOs are occurring during a full attack, does Backswing apply to attacks of opportunity provoked during a full attack?

Why or why not?

Answer 1

It does not

when a two-handed fighter makes a full-attack

This means that you gain the benefits of Backswing only during a full attack, and on all attacks that are part of said full attack.

Attacks of Opportunity break the flow of combat, and are never part of a full attack, but instead, they are like free actions that happen between other actions and at any time. You would gain the benefits of the ability if it said "until the beginning of your next turn/round", "lasts until your next turn" or "this effect lasts until the end of the turn", like Power Attack or Combat Expertise.

Any other interpretation of the ability's text, will also mean that the character only needs to make a single full attack with the feat and will recieve the benefits for the rest of his life, which is funny, but kind of silly.

Jason Nelson (the feat's author) explains how overhand chop and backswing should work. He does not mention attacks of opportunity, but talks about iterative attacks and how backswing and overhand chops affects them:

"This normally means you're only getting a better damage bonus... on your iterative attacks"

And he explains that backswing is used as part of the full attack action.

Which means that instead of a +10/+5 (1d6 + 6/1d6 +6) iterative full-attack, you will do +10/+5 (1d6 + 6/1d6 +8) (str 18, +4 bonus, 1.5 times is +6 bonus, 2 times is +8 bonus). In other words, you get that last 0.5 Strength bonus on your iterative attacks.

Answer 2

If Pathfinder was a law book it would apply (because the trip is an attack, and the AoO comes after). Moreover, if you keep this down-to-earth reading, "all attacks after the first" should get the bonus, even those made the next turn or ten years later, even those made by his allies or his opponents, or people in other countries you don't know about. Yup, when you would take this feat suddenly everyone in the universe should start adding twice your Strength modifier to their damage rolls.

But actually it is not. It relies a lot on tacit understanding and here the tacit meaning is "replace his +1.5*Strength bonus with 2*Strength bonus for all attacks of this full-attack that come after the first". As your AoO is not part of this full-attack you don't get the bonus on it.

This reading of the feat is supported by this comment by the author and more particularly the line:

You only get Backswing when you make multiple attacks with the full attack action, on attacks after your first.

Answer 3

RAW I think it does. The first attack is a trip attempt. The AoO resolves immediately after it is provoked, before the full-attack ends. It is an attack "after the first." The text doesn't specify that the attack must actually be part of the full attack.