Arrow Eruption: useless because it requires "killing" a creature?

[Mikko Kallio]

When I first saw the Arrow Eruption spell (rgr 2, sor/wiz 2) I thought "awesome, a neat AoE spell for gishes and rangers".

But looking at the description more closely, I noticed that you have to "kill" a creature: "You create exact duplicates of the arrow or crossbow bolt you used to kill a creature in the previous round and launch one at enemy creatures within a 30-foot radius of the corpse."

Creatures are dead only when they're reduced to negative hit points equal to their Con score. This means that you often have to keep shooting an already downed foe to be able to use this spell. Most GMs don't bother with calculating negative hit points for mooks (which are the most likely creatures to use to trigger this spell) so it's also more work for the GM.

And what about undead and constructs? Technically, you cannot kill them because they're not living creatures, and the game term "destroyed" is used, not "killed" or "dead" as with living creatures. ("Immediately destroyed when reduced to 0 hit points or less.")

So do you people think this needs errata or is it fine as is? Or does everyone allow players to trigger the spell when you reduce the target creature's hit points to 0 or less, regardless of creature type?

[Diego Rossi]

Against most opponents you will have to fire 1 extra arrow to be sure they are dead (assuming you are an archer build, no reason to memorize the spell otherwise). Generally it is the second or later attack of a full attack so you are sacrificing an attack with a lower chance to hit in exchange for a area attack on the following round.

Undead and constructs are creatures, so being destroyed should count as being killed. That will make this spell more useful against them, as you will "see" immediately that they have been killed, making its use easier.

All considered, it is a bit situational but acceptable.

I am sure a lot of GM would consider a downed enemy "dead" for this spell use.

[Fatespinner]

Personally, yes, I'd allow an "unconscious" character to be used as a valid catalyst for this spell. Additionally, I would have the spell deal the arrow's damage to the creature who served as it's origin, thus all but guaranteeing that if the creature wasn't dead before the spell, it almost certainly is afterwards.