LonePaladin said:
Sorry, hyp, but that's not quite right. Improved Trip specifically says otherwise, as Legildur stated. Free attack rolls that follow up on a prior attack (including the one granted by Improved Trip, as well as Cleave and Great Cleave) retain all the bonuses and penalties you took into the original attack; the only numbers that change are the ones that are circumstantial (such as flanking, higher ground, etc.).
True Strike
is a circumstantial bonus. The circumstance is that there is a spell in effect; after the first attack, which discharges the spell, there is no spell in effect, and you can't gain a bonus from a spell that isn't there.
For what it's worth, the 3E Main FAQ addressed this question directly:
If you use the true strike spell and you get a threat, does
the +20 bonus from the apply to the critical confirmation
roll? Would the +20 bonus apply to the extra attacks you
get from the Cleave, Great Cleave, or Whirlwind attack
feats?
When you roll to confirm a critical, you use whatever
bonuses applied to the attack roll that made the threat, no
matter where those bonuses came from.
True strike affects only one attack. (Rolling to confirm a
critical is not a separate attack for this purpose.) If you make
multiple attacks in a round, your bonus from true strike applies
only to the first attack you make, no matter how you managed
to get multiple attacks.
You agree that Cleave considers circumstantial modifiers separately - you don't get to apply a flanking bonus to an unflanked second opponent just because the first opponent was flanked, for example. In the same way, you can't apply a bonus from a non-existent spell to an second opponent just because it existed for the first opponent.
Similarly, there are circumstantial modifiers that differ between the initial trip and the followup attack. Taken to an extreme, we can say that if we had not used the first attack to trip, the opponent would not be prone, and thus he should not incur a -4 to AC against the second attack - since it is made as if we had not used an attack to trip. But the -4
does apply, because circumstances have changed. In the same way, the circumstances relating to True Strike have changed - on the trip attack, the spell was in effect, but on the followup attack, the spell has already discharged and is not in effect.
-Hyp.