Justin Bacon said:
Then why should dropping the first guy ever result in someone else being more vulnerable to an attack?
The second guy (A) is not more vulnerable to an attack. He is only just as vulnerable to an attack as if the first guy (B) was not there. If B was not there, C could have attacked A anyway. The way I see it, Cleave allows C to dispatch B with ease, so easily that his efforts against A are not hampered at all. This is represented by the fact that he gets an attack roll against A (representing his efforts at attacking A in the round) even though he has already made an attack roll against B.
(Note: B changed to C in this quote to standardize)
A and C are facing off in combat. Someone releases a pack of dire weasels who all carefully move up to within 5 feet of C. On his turn, C uses his high BAB to make an attack against each dire weasel; kills each in turn; and uses each dire weasel death to Cleave into A.
Again, as in the previous example, C's Great Cleave feat makes the additional opponents irrelevant, but he doesn't get any more attacks against A than he would have got in a round. Had he ignored the dire weasels, he could still have made the same attacks against A. His Great Cleave feat just makes him so efficient at dispatching weak opponents like the dire weasels (C must be awfully high level if he can regularly drop a dire weasel with one blow) that his effectiveness against A is not hampered at all.
The AoO element of your scenario is essentially irrelevant.
Yes it is, and this is why. The fundamental premise I'm working on is this: an AOO happens when you lower your defenses (barring special abilities that allow you to take AOOs even when your opponent normally wouldn't provoke them, such as a rogue's Opportunist ability, and the Hold the Line feat). If you don't lower your defenses, you shouldn't be hit with what effectively is an AOO.
If A and C are fighting each other, C's damage potential against A is approximated by the attack rolls that C gets by virtue of his BAB. If A does something that causes him to lower his defences, e.g. A attempts to disarm C or sunder his weapon without the appropriate feat, or moves through C's threatened area, this lapse in A's defences is represented by C being able to take an AOO against A, thus increasing C's damage potential against A.
If you allow Cleaving off an AOO, C's damage potential against can A increase not because A has lowered his defences, but because someone else (B) did. Take a numerical example. Assume A and C are both 4th-level fighters. In a normal round, C gets just one attack roll against A. Now, three dire rats run behind C. With Combat Reflexes and a Dexterity of 14, C gets AOOs on all three of the dire rats, and with a bit of luck, drops them all (assuming a Strength of 18 and a
+1 greatsword, C only needs 6 or better to hit a normal dire rat's AC of 15, and automatically deals enough damage to drop each one on a hit). If C then uses Great Cleave, he then gets three extra attack rolls in that round against A.
What I don't particularly like is how C's damage potential against A can quadruple in one round, not because A did anything to lower his defences, but because three weak opponents happened to provoke AOOs from C. This is why I don't think it's fair.
Personally, I wouldn't overrule cleaving from inivisible opponents in either case. I'd try to come up with some game-world explanation: Maybe killing dire weasels really gets B's blood pumping. Maybe invisible dire weasel blood splashing in A's eyes distracted him. And so forth.
But the rules are clear. And I'm not going to nerf C just because A can't see the opponents B is attacking. Otherwise we start getting into whacko scenarios in which A closes his eyes to avoid cleave attempts from C.
Just to clarify: I've no problems with Cleaving off invisible opponents, just Cleaving off AOOs. And I agree that you can explain Cleaving off an AOO in this manner. I just don't like it that's all. There's no accounting for taste, right?
