just my 2 bits
Cleave based on an AoO, sure
AoO provoked by friendly summoned creature, nope
But what if the magic user summons a creature and tells it to attack the fighter-type in question? I think the spell says something about summoned creatures automatically attacking your enemies, so they know who the "good guys" are, therefore they won't attack friendly PCs even if ordered to do so, therefore they cannot provoke an AoO from the fighter type. *whew*
On the other hand, some of these "morality" arguments could be applied to other situations (using summoned creatures to set off traps, grapple enemies while you shoot them with Area spells), so I'll put in another 2 bits for that. As quoted by Ridley's cohort, the summoned creatures are not "killed" by any action you take, they reform 24 hrs later on their home plane, none the worse for wear. Effectively, if you "kill" a summoned creature, all you are killing is a spell, which carries no moral stigma. Therefore I have no problem letting good clerics use summoned creatures in any way they desire(except attacking the party, see above). Specifically addressing storm raven's argument: If a good creature isn't allowed to cause the death of a summoned creature for their own convienience, then they wouldn't be allowed to summon a creature into any situation where said creature is likely to be killed, which is nearly all situations in which the spell will be used. (note, btw, that I'm not talking about the party directly attacking the summoned creature, but putting it in harm's way. The rest of my argument shows why a good party would have no need to directly attack an allied summoned creature)
As far as wether cleave-on-AoO should be allowed or not, there seem to be two arguments: cenematic and game balance.
Cenematic: " it just doesn't make sense for X situation to occur."
ok, this is a game, the activities portrayed therin take place in a fictional realm not necessarily subject to the same conditions as are present in our reality. We're talking magic here people and that applies no less to the "mundane" classes of fighters and rogues than it does to the spellcasters.
game balance: err. actually I haven't seen any game balance arguments, all I've see is people saying that it isn't "fair" that, in some situations an individual can become subject to an attack due to another individual provoking an AoO. I don't see how this is any less fair than someone triggering a trap which ends up hurting someone else, or someone making too much noise and giving away the presence or location of the party. If someone screws up and ends up hurting the rest of the party you need to chew them out for being stupid and/or plan around their inadequacies in the future. Oh, and I hold evil groups to the same reasoning which prevents "sack of puppies" attack as I do good groups. Namely allies don't provoke AoOs, therefore it never gets to the AoO/cleave point.
And just to be a hypocrite, here's some cenematic reasoning for cleave: You are relying on your allies to cover you and/or to take up some of the attention of your enemy. When one of them drops, there is a moment of opportunity while you are shifting your defense to adapt to the new tactical situation that an individual with cleave can take advantage of if they dropped the ally in question. Why just that person? because as the individual who delivered the blow, they are the first to realise that the target is going to drop, so they have an edge on everyone else. This also addresses the situation where the dropped individual is nowhere near the target of the cleave attack. The relationship between the two targets (AoO provoker and guy that gets cleaved to) is the individual performing the attack, now that the attacker has one less thing to worry about, they can make an unexpected move and catch anyone they threaten with a follow-up to the first attack. Lastly, this also illustrates why an attacker cannot perform an AoO on an ally in order to gain a cleave attack on an enemy. The ally does not threaten the attacker, so elliminating them does not change the combat situation in the favor of the attacker.
An important thing to remember here is that one attack does not necessarily correspond to one physical swing or thrust of a weapon. A single attack may correspond to a number of feints, shifts of weight, stance changes, parray attempts, psudo-magical combat techniques, etc... which culminates in a single potential hit. Therefore the AoO/cleave combo does not necessarily consist of a killing blow followed by a single strike at a different opponent (though I'll allow the player to describe it as such if they want to), it might be a subtle opening in a target's defenses which allows the combatant who is cleaving to make a series of actions which culminate in a potential hit.
Yea I'm long-winded, I know it.
