Reverse Missiles / not an "attack"
 

In a thread on another forum, a poster opined that the Reverse Missiles spell does not work against suppressing fire, on the premise that it's not actually an "attack," and that RAW leans on the term "attacker" used throughout.

Now at my own table, I'd rule that as nonsense; someone shooting bullets at me isn't off the hook just because he might not explicitly be attempting to hit *me*, and furthermore that reduces the effectiveness of an expensive and prerequisite-laden spell. (Beyond that, how in the merry hell is the spell divining the intent of the "attacker?" The spell's sentient? It's able to read the mind of the attacker, divine his intent and act upon it? Does it then not work at all upon an automatic trap/weapon system, or a missile with internal homing capability? And if so, shouldn't Mind-Reading be thrown into the prerequisite basket?)

But now I'm curious. Is that actually the intent of RAW, or is "attacker" just a simple way not to have to repeat "person initially launching the missile?"

Re: Reverse Missiles / not an "attack"
 

B.409-410 under Suppression Fires says you must attack all targets that enter the area.
I don't think Reverse Missile would have any issues deflecting those attacks.

Re: Reverse Missiles / not an "attack"
 

I concur with your interpretation: nonsense, indeed.

Even if we were being extremely conservative in our reading, the text explicitly says that "you must attack anyone – friend or foe – who enters the zone" (B410), so I don't see how you could possibly interpret that as not an attack.

Re: Reverse Missiles / not an "attack"
 

I had thought Reverse Missiles didn't work against shrapnel from an explosion, but a bit of Googling brought up this Krommpost, which states outright that, while the explosion itself is unaffected by Reverse Missiles, the shrapnel would be bounced away (presumably back to the hex where the explosive was). Considering it's hard to get a more impersonal missile then the "to whom it may concern" shrapnel from an explosion, I'd say even if Suppression Fire is considered not to involve an explicit attack on the Missile Shielded character, the projectiles still get bounced back.

Re: Reverse Missiles / not an "attack"
 

If it helps, the prerequisite spell Missile Shield explicitly stops shrapnel

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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).

Re: Reverse Missiles / not an "attack"
 

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?

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

My take is that we need to take into account what the spell's supposed to do, which is to attack the attacker with his own missile. If air resistance was to be a factor, one would expect that the spell would have language along the lines of "Double the range for the purposes of the attacker's 'to hit' roll, as well as assessing any resulting damage."

Re: Reverse Missiles / not an "attack"
 

GURPS ranged attacks are hitscan weapons*, and wherever you are when you make an attack, that's where you are when the projectile returns to you - there is no travel time involved. You need look no further than the penalties for Range to determine this - something that is twice as far away looks half as large, and lo, both situations (twice as far, or half as large) result in the same -2 to hit (you can repeat this for anything else; basically, Range penalties just treat the target as though it were 2 yards away but only as large as it appears... which is exactly how hitscan weapons work).

If you're wanting to get more simulationist than the default, you'll need to make some decisions. How does the spell determine the point of origin, and how is this point fixed in space? Maybe the projectile "remembers" where it came from, and the spell tells it to go back home. The origin point is obviously set relative to the planet (otherwise, with how quickly Earth hurtles through space, I suspect anything beyond point-blank would wildly miss the attacker when it returned), but what else could it be set relative to? A vehicle (so Reverse Missiles still works as-advertised on a speeding train)? A mount (so that horse archer isn't immune)? A shooter (so a teleporting mage isn't necessarily safe.... although I'd argue the projectile should still be subject to 1/2D and Max Range under such a simulationist handling)? What happens if there's something in the way of the projectile returning, that wasn't there when it initially departed? How you answer these questions may well modify how Reverse Missiles functions in your game.

*For those unfamiliar with the term, this is the way projectile weapons work in many - mostly older - video games. When you attack, rather than your weapon producing a projectile that must collide with your target's hitbox to have an effect, the game simply checks to see if your aimpoint is in line with said hitbox when you attack - if it is, the target immediately takes damage. There are some games where there's a visual effect that's slower than the instantaneous damage effect, which can have humorous results - such as a foe falling dead, then being struck by the fireball that killed it (or an arrow fired at an erratically-moving target gaining homing capabilities).

Re: Reverse Missiles / not an "attack"
 

You are allowed to dodge the returning attack.

Re: Reverse Missiles / not an "attack"
 

However, that requires that you can see it coming, or otherwise be aware of it. This is fine for large, slow missiles, but not for bullets.

Re: Reverse Missiles / not an "attack"
 

In a vacuum, reversing path will work unless the attacker was moving (in which case it will wind up returning to the point the projectile was fired from). In atmosphere, it's not going to work correctly for long range fire, but it's probably safely ignorable at normal combat ranges.

Re: Reverse Missiles / not an "attack"
 

I think it the case of shrapnel it would revese back to center of AE rather than where missle was launched, same with a grenade.

Re: Reverse Missiles / not an "attack"
 

Or worse case scenario; the original 'archer' scores a critical hit with his 'arrow', he gets no defense since the incoming Reversed attack is still a critical hit.

Re: Reverse Missiles / not an "attack"
 

However with a homing or multiple attack projectile Missile Shield gets to a comedy level. A bullet with such properties fired on a called shot head would FREX somewhat resemble an Ioun Stone.

Orbit and Orbit the head, never to strike...

Re: Reverse Missiles / not an "attack"
 

A Critical Success should never be detrimental to the character rolling it. In this case, at worst I’d have the reversed missile wind up missing the attacker. I’d honestly be tempted to have something like a 1/6 chance of it bypassing the shield and perhaps a 1/6 or 2/6 chance of getting deflected into another target; in either case, there would be no roll on the Critical Hit Table.

Re: Reverse Missiles / not an "attack"
 

No, it isn't. Actually I'd argue that a critical hit would at the least be a guaranteed miss by the Reverse Missile spell because critical hits mean you got lucky.

Re: Reverse Missiles / not an "attack"
 

Critical hits would interfere with Blocking Spells like Deflect Missile since crit hits prohibit active defenses, but Reverse Missiles doesn't use your active defense - it's a Regular Spell so I don't think a Critical Hit would interfere with how it operates in any way, unless you had it prepped via Reflex.

Re: Reverse Missiles / not an "attack"
 

Critical Successes let you do the improbable, even the extremely improbable but not the impossible.

Each GM runs their own game of course but an 'archer's' skill does not negate a magical effect.

If an 'archer' rolled a 3 attempting to shoot a mage protected by a Force Dome spell I would not have the 'arrow' pass through and hit the mage.

I do not see a substantial difference with Reverse Missiles.

There are extant counters and tactics to deal with mages, this spell IMHO is no different nor do I see a reason to treat it differently.

But as always Rule #1 is it's the GM's game.

Re: Reverse Missiles / not an "attack"
 

Even so it doesn't seem right that the defender could benefit in any way from the attacker's lucky roll which is why I think the attacker certainly wouldn't get the benefits of a critical hit and I would go so far as to say the arrow would go astray thanks to a bit of wind, a chance obstacle, or just enough unplanned movement on the attacker's part. It's not changing how the spell works, just the chance permutations of the arrows course back to its origin point.

Re: Reverse Missiles / not an "attack"
 

Well the defender is not benefiting from the attacker's roll, he is benefiting from having cast the right spell at the right time.

Personally as a 'combat' spell I prefer Invisibility to Reverse Missiles. It is cheaper to cast and an Invisible Mage is generally safer than one under Reverse Missiles, can do a lot more offensively, and it is a much better general utility spell.

Of course I also 80+% of the time tend to take Luck to keep from being Frelled over by the dice...because it can happen. The case we are speaking of would be just one of many.

Re: Reverse Missiles / not an "attack"
 

(nods) With the 4th edition change, at this point, anyone who doesn't take Luck (except under the most extreme CP pressure, for RP considerations, or under GM veto) as immunization against critical failures is selling their characters badly short.

Re: Reverse Missiles / not an "attack"
 

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).

Re: Reverse Missiles / not an "attack"
 

Yeah, that. Note that any kind of physical reversal process runs up against the problem of what happens if the shooter moved, and the more serious one that it would almost always fail to threaten the shooter even if he has not. The missile should hit his weapon, or smoothly return to his quiver, or pass through the point in space where the end of his sling was when he released the string....

The downside of the magic being able to hit the shooter anyway is that logic would suggest it should be fairly trivial to design a variant spell that uses a similar process to propel something the mage tosses randomly into the air so that it infallibly hits the eye slits of anyone he designates as the "shooter", possibly at hypersonic speeds at ranges over the horizon, given that the Reverse spell seems to work on such projectiles. Now you need a second justification for why magic does something that doesn't make sense to prevent that, which is likely to require a third and a fourth and...

It may be better to just call it from the beginning, it's magic, it doesn't make sense, and stop wasting time trying to figure it out or develop exploits. The downside there is some exploits are pretty cool, and it's a shame to lose them.

There really is no good way to balance all of those in a way that doesn't involve case by case arbitrary rulings. Mind you if magic is sapient, which a lot of evidence seems to support, the spell spirits or whatever might well [change their minds] from casting to casting and alter what exploits do or don't work from day to day.

Re: Reverse Missiles / not an "attack"
 

I should note here the post you were responding to was simply arguing for the returning missile to miss the attacker - I was the one who suggested there may be a chance for the arrow to pass through the Reverse Missiles (or possibly deflect into another target the attacker would like to hit). And it would be a chance, not a guarantee - I offhand suggested 1/6 just to make the rolling simple (roll 1d, penetrate on a 1, strike something else on a 2 or maybe 3, hit nothing of importance otherwise), but a full 3d roll could be used instead, perhaps needing a 3 or 4 to bypass, and a 5 or 6 to hit a different target.

For the case of Force Dome, I had thought there was an "Ignores target's DR" result on the Critical Hit Table, but apparently there isn't. With that in mind, it's probably inappropriate for there to be a chance to bypass Reverse Missiles - in a sense, Force Dome gives Infinite DR against everything, Missile Shield gives Infinite DR against Missiles Only, and Reverse Missiles upgrades Missile Shield's Infinite DR to have Reflective - but I'd still argue for the return missile to miss the attacker, so there's at least some benefit to having a Critical Success.

Re: Reverse Missiles / not an "attack"
 

Okay, that I'll buy. It still doesn't cover the missile's ability to track a moving shooter, but, as you say, it's magic.

Re: Reverse Missiles / not an "attack"
 

There is - for Critical Head Blows, and it's only on a roll of '3', so pretty uncommon.

I think I'd rule that a critical hit to someone with Reverse Missiles up would still bounce back and hit the shooter, but only as an ordinary hit. I've already established a ruling (it came up in play) that reversed shots hit randomly rolled locations, regardless of whether the original shot was aimed at a specific location or not.

Re: Reverse Missiles / not an "attack"
 

LoL I guess I am not that nice...

Although if I were playing the mage in this theoretical I would argue for the 'bowman' to have his bowstring snap or some similar minor misfortune preventing him from getting a clean shot off.

That way the critical does good for him (saves him from putting an arrow into his own chest) without tactically 'negating' the mage's spell (because if an archer shoots an arrow at Mr. Robe and Pointy Hat and it zips up to him and then arcs back to just miss the original archer NO ONE is going to be second to shoot an arrow at Mr. R+PH).

That way the mage might still 'take down' someone with his expensive spell (if he just wanted protection w/o the barb he would go with Missile Shield) it is just unlikely to be the lucky holder of the critical success in question.

As always YMMV.

Re: Reverse Missiles / not an "attack"
 

I generally go by a rule that a Critical Success should not be worse than a normal Success. Your initial suggestion, that a character who rolls a Critical Success against a foe with Reverse Missiles up shouldn't get a chance to get out of the way of the returning missile (which apparently characters who have normal Successes do) would clearly violate that. Anything that mimics a Critical Failure, such as the character's weapon breaking, I feel would also violate that. Treating it like a normal Success (normal chance to defend) would be acceptable, as would an option making it better than a normal Success - the returning missile missing outright, the character getting a bonus (probably +2) on their Dodge to avoid getting hit by the returning missile, or even having the character miss, would all be acceptable. My initial suggestion of having a chance to bypass the spell or have the missile reverse into a different target probably goes too far in the other direction (although I do like the idea that such protection isn't absolute).

Re: Reverse Missiles / not an "attack"
 

How about the principle that a Reverse Missiles should always be more useful than a Missile Shield or even not casting the Spell at all?

The mage spent his cp to learn the Spell, went through the necessary ritual, rolled to Cast the Spell and paid the FP but you're not giving him what he paid for.

The minimum acceptable to me if I was the Mage would be the bowman taking a regular hit but I'd feel like I paid the price to get what the rules said would happen.

Re: Reverse Missiles / not an "attack"
 

In normal circumstances I agree. However the Reverse Missiles in the example makes the circumstances different for me at least.

I am haven't GM'ed in quite a while...but if I put the hat back on I would still run it the way I originally posted.

Sometimes you just walk right into a left hook...

Re: Reverse Missiles / not an "attack"
 

That's not a rule I would subscribe to, just as I don't subscribe to the rule that a Critical Success must always be better than a regular Success (or using a Fine weapon must always be better than using a Good one, or similar). To get the reductio ad absurdum out of the way, Reverse Missile isn't always more useful than a Missile Shield or not having cast the spell at all when up against a melee attack. Also, it's actually worse than having not cast a spell at all when someone uses Detect Magic, as they can now detect you.

But such ridiculousness out of the way, I wouldn't have a problem with a rule that Reverse Missiles is never worse (which isn't the same as "is always better") than Missile Shield, seeing as in many ways it is Missile Shield+. The version where the attacker gets a bonus to their defense if they rolled a critical hit is still better than Missile Shield, just not by as much as normal. The version where the reversed missile automatically misses is equal. If you have a chance of Reverse Missile failing against a crit, Missile Shield should similarly have such a chance. The only one of my suggestions where Reverse Missiles would be worse than Missile Shield would be if the missile winds up hitting one of the caster's allies instead... so such an option probably shouldn't be in play (or if it is, Missile Shield should either similarly have that failure mode, or have its chance to fail outright be equal to the sum of the chances of Reverse Missiles failing outright and being deflected).

Re: Reverse Missiles / not an "attack"
 

Oh no. When you've paid for Reverse Missiles but only get Missile Shield you're worse off then. By several FP and your blown tactical planning as well.

What the mage has paid for is every archer who rolls a hit against the mage to suffer that hit against himself instead. I'm not seeing any reason to not give the mage what he paid for.

If you had warned me before play began I'd have known not to take Reverse Missiles. If you came up with this interpretation on the fly it would have caused some hard feelings.

Re: Reverse Missiles / not an "attack"
 

A character who has a Balanced Superfine Nanothorn Thrusting Broadsword, Weapon Bond with it, a compatible Weapon Master, and several levels of Improved Parry (Broadsword) has invested a sizable sum of money and points into being an absolute monster when it comes to Parrying melee attacks - he/she has a sizable bonus to Parry (+1 from Balanced+Weapon Bond, plus whatever levels of Enhanced Parry he/she has taken), can readily Parry multiple attacks in a round, and damages whatever weapons he/she Parries.

All of that means nothing if the foe rolls a Critical Hit. By your logic, he'd have been better off using a cheap plastic toy, with no compatible traits, as at least then he wouldn't have wasted all that money and points.

And don't forget that's what we're talking about here - what happens when the attacker rolls a crit. Would you really abandon Reverse Missiles because there's generally a 1.85% chance for it to only be as good as Missile Shield, potentially going up to 9.25% against really powerful enemies (those with final effective skill 16 or higher)?

That said, if it hadn't yet come up in play and an enemy rolled a Critical Success against a PC with Reverse Missiles up*, and the player strongly objected to the ruling, I'd probably suggest the "attacker gets +2 to Dodge" variant as a compromise. If that still didn't fly, I'd let the table vote on it - either this Critical Success gets a new special effect (and any Critical Success against Reverse Missiles - be it on a PC, enemy, ally, etc - would get the same special effect), or no Critical Successes - theirs or those of OpFor - will get new special effects for the entire campaign.

*Or, more likely, a PC with Reflective DR - I'm not a fan of the default magic system.

Re: Reverse Missiles / not an "attack"
 

If a GM made that ruling ahead of time in 90% of games it would make absolutely no difference in my decision making, because reverse missiles is prone to being either ridiculously overpowered or utterly useless, depending on the nature of the opposition, and no ruling on critical hits is going to significantly change that (even critical hits totally bypassing the spell wouldn't do that, though it would alter tactics to make baiting out attacks less appealing).

Re: Reverse Missiles / not an "attack"
 

I'd point out that rule is that critical hits permit no Active Defense, not that they bypass all defenses- an Insubstantial character, for example, can stand around all day with his attackers rolling all the criticals they like, and still won't take any damage unless the attacks explicitly affect insubstantial foes.

Re: Reverse Missiles / not an "attack"
 

True this also brought to my mind that how much of a investment Reverse Missiles is depends on the base assumptions of a campaign.

500+ Supers...minimal
250 DF...a little more but not much
100-150 Low Fantasy...now the points in prereqs add up and the FP look bigger.

IMHO Reverse Missiles works only if it is a suprise...otherwise it is just a more expensive Missile Shield.

Re: Reverse Missiles / not an "attack"
 

I'd be avoiding it because it would look like the GM didn't like PCs using it. If something bothers the GM enough for him to make House Rules about it's easier to avoid it altogether in most cases.

Re: Reverse Missiles / not an "attack"
 

I think we've played the crit Vs Reverse Missiles in two different ways in the past in my tables at different times: either the shooter crits themselves or the crit passes through the Reverse Missiles. Either way is fine, really, as long as you keep it consistent in the same campaign.

Moving shooter is one that we haven't had to adjudicate in my table ever, and I don't think it's likely to come up too often as GURPS defines most missile attacks as travelling in essence instantaneously. But if it came up (like shooter shooting and then simultaneously getting teleported somewhere else, or if we started to care about the missile travel time), I would be inclined as a GM to rule in favour of the players when it first comes up, and then would use that same logic against them when it comes up again and the roles are reversed... I find that this way goes better with players in general.

Re: Reverse Missiles / not an "attack"
 

This might come down to how we read "If the attacker’s “to hit” roll is successful, he hits himself"

Does this necessarily mean contact, or just that it returns as if a successful to-hit roll happened, with all the usual countermeasures possible?

I don't know if any of the usual problems would exist though - if someone made a ranged deceptive attack (took a penalty to hit so there would be a penalty to dodge) I think maybe that ought to only penalize the original target but defenses from the new target could be unmodified.

Whatever the policy, Damage Reduction w/ Reflexive +100% should probably work the same.

Re: Reverse Missiles / not an "attack"
 

Barring official guidance, I'd rule the latter: the attacker inflicts a successful hit on himself, which he then can defend in the usual ways. (Reversing a bullet, given the element of surprise, I expect the usual way would equate to "Gape owlishly at the fresh hole in your chest.")

Re: Reverse Missiles / not an "attack"
 

If it's a gun fight on both sides, then any dodging he'd do against bullets in general would apply to his reversed bullet. But what about firing from cover?

Re: Reverse Missiles / not an "attack"
 

A previous poster suggested having the return missile hit a random hit location; an option here would be to do just that, and if the return missile rolls a hit location that is behind cover, it strikes the cover first (which will typically mean it strikes the cover instead, unless the character is using cover that his/her own weapon will reliably penetrate). Or you can assume the spell will only "target" those hit locations that are exposed... or even that it ignores cover. That would all be up to the GM, of course. My personal inclination would be to just use the "random hit location" option.

Of course, if using the rules from Tactical Shooting, a lot of the time the shooter won't get a defense against a return missile - not because it's a surprise, but because the shooter will have used All Out Attack in order to take advantage of any Aiming done in the previous round(s). For a modern-ish battlefield where Reverse Missiles are potentially in play, I could see weapon systems like the Cornershot being rather popular.

Re: Reverse Missiles / not an "attack"
 

That's what happened the only time I've been in that situation in a game. It was a rifle bullet within 1/2D range, which took me to just above the first death check, so making the HT roll next turn to shout a warning was quite important.
I was firing from the prone position, with no indication that the target was aware of me, or had special defences. No dodge attempted; I may have used All-Out Attack for the +1, since it was pretty dark.

Re: Reverse Missiles / not an "attack"
 

Sounds about the way I would play it. Reverse Missiles Golden Rule, 'You get what you give'.

Bravo on warning your group. Reverse Missiles then just became an expensive Missile Shield.

Re: Reverse Missiles / not an "attack"
 

The one time I've had Reverse Missiles in play, the party was fighting a dragon, so they pulled out their major firepower - Martini-Henry rifles in .450.

As the shooters had god-like Guns skills, and the rest of their gear, including armour, was TL3/4, the first shooter got a nasty surprise (a smashed up arm, as I recall).

Re: Reverse Missiles / not an "attack"
 

makes me wonder what would happen if there was a pair of mages both w/ Reverse Missiles shooting at each other

That kind of dilemma could exist with a pair of 'Reflective DR' foes shooting at each other too.

Re: Reverse Missiles / not an "attack"
 

Don't stand between them.

I'd rule the attacks would bounce back and forth until they ran out of range.

Re: Reverse Missiles / not an "attack"
 

For the former, in the thread I linked previously, Kromm stated you should have the spells basically run a Quick Contest between them (using the skill level they were each cast at), and whichever lost winds up failing to protect - basically, the projectile bounces between them a few times until it manages to get past. If using this interpretation, for Reflective DR, you'd instead probably have the characters roll as though they were using Power Parries (to be clear, they aren't using such, we just use the same scores since we need something to roll against, and that seems the most appropriate option).

Personally, I think Rupert's option (they bounce back and forth until they run out of Range) is probably better.

Re: Reverse Missiles / not an "attack"
 

I'm now imagining two rows facing each other. When the missile gets to you and reverses you fire. Repeat. Then one row drops to the ground. Sort of a spell laser.

Re: Reverse Missiles / not an "attack"
 

With archery, a potential factor might be "how many seconds does it take for that arrow to do so?" For practical purposes, that's a detail GURPS avoids generally (at least as far as I've ever seen), but an arrow doesn't traverse a couple hundred yards in a second flat. Two? Three?


Seems like a GM would just have to apply common sense. If Shooter A is using a firing slit/pavise/sandbags, then the Reversed missile has the same penalties to hit him as any other ranged attack against Shooter A. If Shooter A is sticking his weapon over a parapet to fire blindly, then there's a chance (and not a great one) that the Reversed missile clips a hand. Etc.

Re: Reverse Missiles / not an "attack"
 

A brief bit of Googling indicates a modern recurve bow tends to fling arrows at somewhere around 170 feet per second, while a modern compound bow tend to fling them at around 260 feet per second instead. Heavier arrows result in slower speeds, higher draw weight results in higher speeds, all else being equal. Part of me is tempted to try to work out a method of determining velocity - perhaps diving into "The Deadly Spring" - but I suspect that way lies madness. I'd say just go with Move 70 (somewhere between those two values) if it matters. Note there are rules for time of flight to matter in Tactical Shooting - they still resolve the hit instantly, but if it takes more than a second to arrive you roll 1d-4 for each full second, and add this to the character's effective skill (average -1.5 to hit per second, but it's possible for the foe to accidentally more-or-less walk into the path of the bullet, for a bonus), to represent that there may have been unpredictable movement or similar in the interim.

Re: Reverse Missiles / not an "attack"
 

It might be more interesting with variable DR (ie you buy 2d DR for the cost of 7 DR) or with ablative DR since the bouncing could get past a low roll or eventually wear it down.

Re: Reverse Missiles / not an "attack"
 

Ignoring the bizarreness of variable DR (note that the Armor as Dice rules don't involve actually rolling for DR - rather, 2d DR reduces a 3d+1 attack into a 1d+1 attack), if using Kromm's suggested Quick Contest in a situation where the number of "bounces" matters, I'd give each character one free bounce (the effect normally doesn't have a chance of failure), then if they succeed at their roll, they'd get additional bounces equal to MoS+1 (once they run out of bounces, they get hit). So, let's say one character has MoS 3 and the other has MoS 5; the character with MoS 3 was the initial target of the attack (and thus has their DR apply first). These characters thus can have up to 5 bounces and 7 bounces, respectively, before the effect fails to work. So the first character has the projectile bounce off, then the second, then first, second, first, second, first, second, first, second... and finally the first character takes a hit and the sequence ends. But if the second character had Ablative DR, it's possible the first character could avoid that hit, if the second character's DR is depleted prior to bounce number 10.

Of course, as I stated above, my inclination would be more toward just having the projectile bounce between the two until it runs out of kinetic energy (or maybe just only let it bounce something like 2d-2 times total, after which it's too off-course and outright misses). In that case (particularly if not capping the number of bounces), particularly for characters who are close together relative to the range of the attack, you could have the projectile significantly deplete any sort of ablative/semi-ablative DR.

Re: Reverse Missiles / not an "attack"
 

An easy compromise which doesn't require lots of math would be to base missile speed on Bow ST with a multiplier for bow type.

For example:

Bow ST x 3 x bow type modifier = fps. FPS/3 = Move

Modifier

2 for Shortbows
3 for Longbows
+1 for Composite construction
+1 for Recurve/Compound construction.
+1 for TL7+ materials

E.g.,

TL8 ST 15 Composite Recurve Longbow = 15 x 3 x 6 = 270 fps = Move 90
TL 0 ST 10 Self Shortbow = 10 x 3 x 2 = 60 fps = Move 20.

Re: Reverse Missiles / not an "attack"
 

Getting accurate answers pretty much requires computer modeling, but it should come fairly close to sqrt( 2 * energy / (arrow mass + M ) ), where M is a constant that varies with the shape and weight distribution of the bow.

Re: Reverse Missiles / not an "attack"
 

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.

Re: Reverse Missiles / not an "attack"
 

Uh uh. Beyond 1/2 Max. That's not necessarily the same as 1/2D range.

Re: Reverse Missiles / not an "attack"
 

Sure, but determining the kinetic energy requires diving into "The Deadly Spring." Now, you can get a fairly rough idea just by taking the RAW damage and applying the cinematic scale from that article in reverse to determine KE, then apply your equation (with the default 0.1 lb arrows GURPS assumes; I don't think your M value would be necessary, here) to figure out velocity, but I'm not sure it would really be worth the work. Much as Tactical Shooting basically just goes with, IIRC, Move 300 for handgun bullets and Move 600 for rifle bullets, just using the same velocity for all arrows may be the easiest way to handle things.

Re: Reverse Missiles / not an "attack"
 

The problem is in balancing everyone's needs. It's already a 240 page book, and the degree to which all GURPS fantasy players love it can be measured in all the books spelling out alternate treatments of magic, from Thaumatology to Religion to the Dungeon Fantasy line. Would people love it more if it were 350 pages instead? Or be all that less likely to bother with it?

The unfortunate problem is that you can't include every spell, and you can't put enough info into every spell to satisfy everyone, and you sure can't write any spell to make it idiot- or argument-proof. At some point, we just need to rely on our judgment as GMs to make rulings that make sense to us. If the subject came up in my own campaign, I'd do exactly that. The only reason I started this thread was to find out if there was an official answer I could take back to that Reddit topic, but I'd be entirely comfortable with doing things my own way regardless.

Re: Reverse Missiles / not an "attack"
 

No, that's just basic math -- it's equal to the area under the draw weight curve, which will be equal to draw weight * draw length * K", where K is a constant that depends on the design of the bow and is generally going to range between 0.5 and 0.8.

The Deadly Spring suffers from "too much math for a simple approximation, too little math to actually get it right".

Re: Reverse Missiles / not an "attack"
 

And what, pray tell, is the draw weight, draw length, and K-value for a GURPS Regular Bow at ST 11? ST 12? ST 20? I'm talking about determining the velocity of a GURPS bow, not a real one that you have in your hands or have the specifications for.

Just for the heck of it, however, here's what the velocity values look like, using my prior suggestion (determine KE assuming the damage of each bow is on the cinematic scale in "The Deadly Spring," assume 0.1 lb arrows - the GURPS default - and work out velocity from there). This looks at everything from an ST 7/8 shortbow to an ST 29/30 reflex bow; note the damage value is before accounting for things like Fine arrows.

I doubt anyone would want to bother with looking at that at the table, but there you go.

Re: Reverse Missiles / not an "attack"
 

It won't match real world bows because archers use heavier arrows for stronger bows.

Re: Reverse Missiles / not an "attack"
 

Real-world answer: arrow velocity will be 50-70 yards per second; the more powerful bow is just heavier and has a heavier arrow. The max speeds shown there are pretty much impossible even with a modern bow, let alone an ancient bow.