Do feats that improve Power Attack charging damage last until your next turn?

Question

Say you make a Leap Attack with Shock Trooper and a two-handed weapon, taking -5 to attack and assigning the full penalty to AC instead. That's +2 attack, +15 damage, and -7 AC. You also use Karmic Strike, so your total AC penalty is -11.

Now it's an enemy's turn. It seems like they should have an extra +11 to hit you, so there's a good chance they do, provoking your attack of opportunity. I see no reason that you'd keep the charge attack bonus, so you swing with your normal attack modifiers. If this attack of opportunity lands, do you get +15 power attack damage?

Answer 1

• Your baseline Power Attack carries over to the start of your next round.
• The AC Penalties for charge and shock trooper carries over to the start of your next round.
• To hit and damage bonuses from Charge, Leaping Strike, and Shock Trooper, only apply to the one attack made on your turn.

The bonus damage from charge, leap attack, and shock trooper does not persist until the start of your next round, only the penalties to AC does.

Charge

You get a +2 bonus on the attack roll and take a -2 penalty to your AC until the start of your next turn.

"On the attack" signifies that the bonus to attack modifier is singular, and only applies to the attack at the end of the change. The -2 penalty however, persists until the start of your next turn.

Leap Attack

...This attack must follow all the normal rules for using the Jump skill and for making a charge, except that you ignore rough terrain in any squares you jump over.

Again in leap attack we find a singular designator specifically telling us that the bonus damage only applies to the one attack you get to make during the round following the charge / leap.

Heedless Charge (Shock Trooper):

... In addition to normal charge modifiers (which give you a -2 penalty to AC and a +2 bonus on the attack roll), you can assign any portion of the attack roll penalty from Power Attack to your Armor Class instead, up to a maximum equal to your base attack bonus.

Again we find that singular attack reference. Meaning that any bonuses we acquire for this one attack are temporary and do not persist after making this one attack. Restoring power attack to its original functionality following the event.

Penalties to AC persist, as expressly described in charge attack.

Karmic strike is a non issue for carry over, as its a -4 to armor class for a chance of an opportunity strike and does not factor into this stack beyond the ac penalty.

---

There is an argument to be made that since you "traded" the power attack penalty for an AC penalty on your heedless charge, you have fundamentally changed the mechanics of power attack, allowing you to effectively trade AC for damage bonuses for the purposes of opportunity attacks.

This requires a loop hole style reading of a clear sequence of events. Mechanically the interaction (suspension of the power attack penalties) is attached to the temporary side of the charge function. So once the attack is completed, the removal of the power attack penalty goes away, but the penalty to AC persists.

But as stated earlier, the bonus damage from charge and leaping strike do not persist past the singular attack made on your turn as part of the charge.

So at the end of your turn, through the start of your next turn:

• -5 to all attack rolls
• +10 to all damage rolls (Two handed power attack, otherwise +5)
• -11 to Armor class
• One additional attack of opportunity if you are hit.

Answer 2

Charge: No

You get a +2 bonus on the attack roll [that you make at the end of the charge]

This bonus doesn’t persist after you’ve made “the attack” from the end of the charge. Your attacks of opportunity thereafter definitely don’t qualify.

If you have pounce, it is an open question whether or not your full-attack at the end of a charge gets this bonus on all attacks—see this Q&A for details. But attacks of opportunity are definitely out.

Power Attack: Yes

The penalty on attacks and bonus on damage apply until your next turn.

This is pretty straightforward: it explicitly says the penalty and damage apply until your next turn, so they do. You get these effects on your attacks of opportunity.

Leap Attack: Yes

you deal +100% the normal bonus damage from your use of the Power Attack feat

Since your bonus damage from Power Attack persist until your next turn, and this bonus applies to that bonus, this also applies until your next turn. So yes, for the round after using Leap Attack, your attacks of opportunity do increased damage.

Note that the conditions for successfully triggering Leap Attack:

If you cover at least 10 feet of horizontal distance with your jump, and you end your jump in a square from which you threaten your target,

require you to do certain things on your turn. This timing requirement does not apply any restriction to the benefit gained thereafter, however—if you do this thing, then you get the increased Power Attack damage.

Shock Trooper’s heedless charge: Not entirely clear, but probably Yes

Heedless Charge: To use this maneuver, you must charge and make the attack at the end of the charge using your Power Attack feat. The penalty you take on your attack roll must be -5 or worse. In addition to normal charge modifiers (which give you a -2 penalty to AC and a +2 bonus on the attack roll), you can assign any portion of the attack roll penalty from Power Attack to your Armor Class instead, up to a maximum equal to your base attack bonus.

So the thing here is, we are both charging and using Power Attack. The modifications from those effects have different durations, as discussed above. You definitely have to charge in order to be allowed to use this option, but it’s not clear what is being modified here: the charge, or the Power Attack. Considering that the actual option is to move your Power Attack attack penalty to AC, it seems to me much more likely that what we’re modifying here is the Power Attack—and therefore the modification applies as long as Power Attack does, i.e. until your next turn. However, the same sentence also says “In addition to normal charge modifiers,” which could maybe suggest that these are special “charge modifiers” and therefore only apply as long as the charge does. My reading here is that it’s more likely that this is just providing a reminder and confirming that these changes stack with those from a regular charge, but there’s no way to confirm that.

Conclusion

You are correct, or arguably correct, in your analysis. The charge modifiers do not persist, Power Attack and Leap Attack’s modifiers do, and those from heedless charge also persist I think. That corresponds to the −11 AC penalty, +0 attack bonus, +15 damage bonus you list. If heedless charge is limited to just the charge, however, then you are looking at just −2 AC from the charge and −4 from Karmic Strike, so only −6 AC, but also −5 attack.