Reverse Missiles / not an "attack"

[ravenfish]

Originally Posted by Fred Brackin

That's just the range penalty for the increased range and the only roll to hit in the process is the one the original attacker made. If that was successful the Reverse shot is unfailing.

But my point is that whereas, in a vacuum, a moving object with its momentum magically reversed would travel back exactly the way it came, air resistance in an atmosphere would cause such a projectile to move on a different course going back than the one it took coming in (the projectile is moving slower when it approaches the mage then it was moving than when it was launched [assuming both mage and archer are at the same elevation], and it is moving slower yet after being launched back towards the original archer, so it will fall somewhat farther going than coming it if travels over the same distance of ground- whether this results in the archer getting shot in the abdomen or the legs, or whether it results in the arrow ploughing into the ground at his feet, depends on details of ballistics that I am not competent to determine).

EDIT: The Reversed Missile, of course, does hit the archer per the spell description, so my point is that the spell must be doing something slightly more complicated than strictly reversing the path of the incoming missile, presumably throwing in a precise amount of extra force to get the missile exactly back to its origin.

[mlangsdorf]

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?].

Assuming negligible aerodynamic lift from the projectile and a flat path to the target, a bullet fired from an aimed position needs to fall about 1.5m to hit the ground. Gravity acceleration is 10 m/s^2 or so, and the equation to calculate accelerating movement from a standing start is D = 1/2at^2, or solving for t, t = sqrt(2D/a). A is 10, D is 1.5, t is 0.54 s or 0.44 s when firing from the hip, 1 m above the ground.

Typical .45 ACP rounds have a muzzle velocity around 300 m/s (+/- 10%). So if you fire a .45 ACP at a mage with Reverse Missiles who is 90 yards away, it's possible the round would hit the ground instead of reversing into you. But it's unlikely if target is much closer, and if the target is farther away, the bullet is going to be fired at an upwards angle out of the gun so that the bullet drop lets it hit the target, and that complicates the analysis some (or a lot, depending on the range).

Guns that fire faster bullets are going to have relatively longer ranges - a supersonic .308 round covers 350+ meters in 0.5 seconds, for instance, and the optimum range is going to be closer to 200 yards.

For simplicity, I'd pretty much ignore the possibility of a projectile reserved by Reverse Missiles hitting the ground unless the target is beyond half the maximum range of the attacking weapon. If I was feeling really generous, I might make that a quarter the range if the attacker is aiming at the target's feet (or a prone target, etc) and the projectile starts the reversal much closer to the ground.

[ravenfish]

Originally Posted by mlangsdorf

...

Thank you- that's the sort of analysis I was hoping someone here could do. So, for fire at reasonably close range at least, a "dumb" Reverse Missiles would be perfectly functional, but the spell probably has some active targeting component if it still works at great range.

EDIT: For my "Mages of the Enlightenment" setting, which at least makes a pretense of spells functioning based on the simple laws of the universe rather than the caster's intent, and at any rate there is a fairly hard rule that magic has no more intelligence than the caster put into it, I may decide to houserule that the spell is the "dumb" version and steal your ruling about half maximum range- a simplification, as you say, but playable.

[Varyon]

Originally Posted by ravenfish

I am not concerned about air resistance bringing the projectile to a stop, but rather about the projectile being slowed enough that gravity has more time to pull it down before it reaches the target. A marksman firing at long distances can take this into account when aiming; I strongly suspect that the Reverse Missiles would have to make further adjustments when firing the missile back.

If what the spell does is reverse the projectile's velocity state, that could be an issue. But that's not what the spell does - it specifically sends the projectile back at the shooter, which may well require it to arc the shot or similar.

As to "hostile intent" (which I don't think is part of Reverse Missiles, but apparently is part of some spells), that doesn't necessarily require any sort of mind reading. In many settings - particularly various flavors of shounen anime - "hostile intent" is a detectable force/energy that is produced/released by anyone acting as such. It may be possible for someone to engage in hostile action without any hostile intent, but this is likely to be the exception rather than the rule (there's an antagonist in Rurouni Kenshin who has sufficient psychological damage as to not generate such). How to handle that - and if it's even an option - would ultimately be up to the GM.

[Fred Brackin]

Originally Posted by ravenfish

EDIT: For my "Mages of the Enlightenment" setting, which at least makes a pretense of spells functioning based on the simple laws of the universe rather than the caster's intent,

Reverse Missiles doesn't divine intent anyway. It responds to _actions_.

So, assume you have a magical gun that heals beings struck by its' projectiles. Those healing bullets would still get reversed even though they are fired with _helpful_ intent.

[ravenfish]

Originally Posted by Fred Brackin

Reverse Missiles doesn't divine intent anyway. It responds to _actions_.

We established that early on. My remarks since then have focused on its aiming ability, which under the rules-as-written must be considerable (when facing an attack that would have hit the caster, the returning projectile hits the attacker without fail- a feat casters of ordinary missile spells gaze at with envy-, and, against attackers at long range, this cannot be explained by simple reversal of momentum).

[Balor Patch]

How does Reverse Missiles work with Homing or Guided attacks that can have multiple passes?

If a shooter immediately (before the bullet reaches the initial target) teleports to his favorite pub then does the spell know where the pub is?

[ravenfish]

Originally Posted by Balor Patch

If a shooter immediately (before the bullet reaches the initial target) teleports to his favorite pub then does the spell know where the pub is?

Or, if one prefers to avoid the reducto ad absurdum, what happens if the shooter fires while moving and, when the projectile returns, is no longer where he stood when he fired (unlikely if the projectile is a bullet but potentially quite relevant for a horse archer)?

As I said, and having nothing to do with any question of "intent", the rules-as-written Reverse Missiles spell has some amazing targeting skills.

[Fred Brackin]

Originally Posted by Balor Patch

How does Reverse Missiles work with Homing or Guided attacks that can have multiple passes?

s?

Multiple attempts to strike a target only come into play if the first attack misses. Reverse Missiles ignores attacks that would miss its' caster. If a secondary attack would hit then the Reverse Missiles takes effect then and most things considered a "missile" destroy themselves when they hit but won't care if they've been Revered into their original launcher.

If there's something with an IQ score and the ability to move under its' own volition in play that's not a missile. It's actually some sort of character.

[RGTraynor]

Originally Posted by ericthered

The other option is that the missile is "reversed", that is, turned around and sent back on the path from whence it came. This is my favorite opinion, and its supported by the name of the spell, but its hardly an unassailable one.

That's what I'd rule myself, but I agree it's a debatable point, and I wouldn't growl at a GM who ruled otherwise.