Reverse Missiles / not an "attack"

[Pursuivant]

This thread is Part 8061 as to why GURPS 4E Magic needs a massive overhaul.

Reverse Missiles is an expensive spell with a big prerequisite tree, so it ought to be pretty lethal. Given all the possible situations where a mage might cast Reverse Missiles, it deserves way more than a single short paragraph explaining how it works.

My house rules/proposed fixes (collected from clever folks like you all, all the way from sometime in the last millennium) are in line with what other folks have proposed.

* If it flies through the air, it's not alive, is physical or magical, and has the ability to mess up the mage's day, it's an attack.

* Reverse missiles doesn't work against insubstantial non-magical attacks which don't depend on physical force. GM's discretion as to what counts as "physical force." Hostile gusts of wind count, psionic "mental stabs" which work at range don't.

* Missiles don't get any rebound energy when they're bounced back. If they're aimed at the mage from beyond 1/2D range, they don't make it back to the shooter. Likewise, spells/missiles which go past 1/2D range on the return, or otherwise weaken with range do less damage to the attacker when hit.

* Dropped attacks just randomly bounce away, landing at the same distance from the caster as the distance they fell.

* Shrapnel, etc. from ranged attacks which emerge at a distance from the attacker (e.g., grenades, artillery shells) just gets bounced back to the hex from which it originated.

* Anything between the caster, the attacker, and the reserved missile might get hit on a maximum roll of 9- on 3d.

* Roll randomly to determine which part of the attacker gets hit by a returning missile.

* The attacker gets all the benefits of Cover and Cover DR to defend against the returning missile. If the modifiers for Cover, Size, Range, Hit Location, etc. for the attacker to "hit himself" means the missile misses, it just lands in the attacker's hex. Cover DR protects normally.

* Attackers turned defenders get bonuses to Active Defenses against missiles they can see reversing and coming back at them. Usually +1, maybe +2 vs. slow and large missiles.

* Critical hits get through the shield and aren't reversed, but the attacker has to roll again to hit. Only a second CH means a true CH.

* For extra energy, the caster can block all missiles - even Critical Hits. If Critical Hits are reflected they automatically hits the attacker but roll against to see if it's a real CH.

This option makes Reverse Missiles even more brutal, but it's necessary if a mage hopes to survive massed missile or autofire. Otherwise, the law of averages will eventually turn the caster into a pin cushion/pinata.

* Cost can be pro-rated or the spell can be based on TL to defend against extremely heavy or powerful missiles. i.e., you might need to spend extra energy to defend vs. trebuchet shot or learn the TL6+ version of the spell if you want to reverse autofire bullets.

This gives needed game balance in campaigns where magic and high tech missile weapons coexist. While most GURPS Magic spells suffer at TL5+, Reverse Missiles gets turbocharged, making it an almost guaranteed fight ender vs. gun-equipped foes.

Reverse Missiles is NASTY against unsuspecting foes and completely screws missile-only fighters, especially high TL foes who aren't likely to have serious melee/unarmed combat skills.