Reverse Missiles / not an "attack"

[ravenfish]

Originally Posted by Fred Brackin

You don't need an extensive ballistics education. You just be able to read the Gurps stats for "Max" (and "1/2D" is also of interest).

If the total distance traveled by the Reversed projectile exceeds the "Max" stat it does indeed fall to the ground. If it exceeds the "1/2D" it is slowed and does 1/2 damage.

This might happen fairly frequently for thrown weapons but very seldom for bullets whose 1/2 and Max are in hundreds of yards.

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.

(In a vacuum, if an incoming object that has been moving along a ballistic parabola is launched back out with the same speed it came in and in the exact opposite direction, it will move in reverse along the same parabola to pass precisely through the point from which it was launched on its original flight. In an atmosphere, an object so launched would be slowed down over the course of its path, and consequently have fallen slightly farther by the time it reaches said original source. How far "slightly farther" is, and whether it would be enough to miss a man-sized target, would depend on how much the projectile has been slowed- hence my appeal to those with better knowledge of ballistics.)


The 1/2D rules, of course, are a simplification for gaming purposes of the reality that a projectile in an atmosphere is gradually slowing over the whole course of its flight.

[Fred Brackin]

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.d.

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.

[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.

[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.