Reverse Missiles / not an "attack"

[Curmudgeon]

Originally Posted by ravenfish

This is a tempting reading, but it runs into the problem that, due to air resistance slowing the projectile both coming and going, a strict reversal of its direction would almost certainly fall well short of a shooter firing from anything greater than point-blank range [EDIT: I assume, at least- can anyone who knows about ballistics analyze this?]. Unfortunately, this may ultimately be one of those spells that "does exactly what it says on the tin by inexplicable magic"- it works out where the attack came from, and uses the incoming missile for counterbattery fire.

The question is complicated by the fact that some Protection and Warning spells do throw in a mind-reading effect as a free bonus- Watchdog, for example, explicitly checks whether an intruder has "hostile intent" (which raises a host of problems itself- does it fail to warn you when mindless zombies or golems close in to attack, to say nothing of question of using magic or Mind Block to mask hostility).

EDIT: As to the particular question the OP asks, I would rule that "attack" in no way implies "particular hostile intention", and an incoming projectile is returned to its source with no regard for the reason the source lobbed it. If there were any doubt, the Kromm quote mentioned up thread (saying that even shrapnel is deflected back to the site of its source explosion) would force us to conclude that the "attacker" doesn't need to have any intent at all, so hostile intent is clearly not a requirement.

Meh. It's magic, not science. If you need a scientific reason for it to do what it does, here's one that couples magic with science and doesn't require any special aiming effect. The missile itself turns end for end in both the x and y axis so that it's pointy end is facing the shooter (more or less), everything thereafter is simply the missile remembering where it's been (essentially Law of Contagion), one point at a time. As part of its remembering, it remembers the velocity it had at that point and resumes it. In effect, the effect of air resistance on the return path is negligible because the missile is accelerating back to its original muzzle velocity (or equivalent) as it reverses along its course and arrives with full damage potential (i.e. 1/2 D range damage, not Max range damage).