GURPS version of Runequest Multimissile spell?

[thom]

So the wizard PC in my game wants a GURPS version of RuneQuest's Multimissile spell:

"...Each point of Magic Power creates a magical duplicate of the original missile (maximum of 4 for 4 magic points). Roll attacks separately. The first is the original. Any later missiles cannot impale but can do critical damage."

As I see it, this is a One-time effect (I don't think it's reasonable to allow an archer to shoot multiple arrows 10+ times during a 60-second duration spell-but I could be wrong). I'm trying to determine how much FP would be spent for how many additional arrows (max of 4) for a one-time spell. Any thoughts from the Group mind?

thom

[mlangsdorf]

Adding the Explosive modifier to a Missile spell generally increases the energy cost from 1 FP per 1d of damage to 2 FP per 1d of damage. Explosive is a +50% modifier and so is RoF 3.

So I suggest that a spell that adds RoF 3, Rcl 3 to an existing missile weapon should cost 1 FP per 1d of damage of the original attack. This differs from spells like Flame Weapon in that it isn't a maintainable effect and the spell has to be recast for each new attack by the weapon.

I would probably allow variant Missile spells such as Stone Missile Volley at 2 FP per 1d of damage, but that's beyond your question.

[edk926]

I once threw something together like this, although it's completely un-play-tested and based on a spell I saw somewhere through random gurps searches. I don't have a name to credit for the inspiration. Anyway, I went with 2 FP per duplicate with them doing the same potential damage as the original missile. I also put a note that Spell-Archery only affects the original missile if you play with DF any. Prerequisites would be either Bow at a certain skill (for the magical archers) or Duplicate because that's what you are doing with the spell.

[Anaraxes]

Thaumatology p39 has a canonical rule in the "Adjustable Spells" section for trading energy (and reduced skill) to add Enhancements to spells.

I suspect in this case it would be considered too expensive by players. RoF 3 is +50% (Rapid Fire, B108), which translates to +10 FP and -10 to skill according to this rule. There might be some cases where the Multiple Projectile (like a shotgun) effect would be useful, or even a high rate of fire to take advantage of the to-hit bonus even if it craters your spell success roll, to get a Hail Mary effect on a massive attack.

[thom]

Originally Posted by mlangsdorf

Adding the Explosive modifier to a Missile spell generally increases the energy cost from 1 FP per 1d of damage to 2 FP per 1d of damage. Explosive is a +50% modifier and so is RoF 3.

So I suggest that a spell that adds RoF 3, Rcl 3 to an existing missile weapon should cost 1 FP per 1d of damage of the original attack. This differs from spells like Flame Weapon in that it isn't a maintainable effect and the spell has to be recast for each new attack by the weapon.

Originally Posted by Anaraxes

I suspect in this case it would be considered too expensive by players. RoF 3 is +50% (Rapid Fire, B108), which translates to +10 FP and -10 to skill according to this rule. There might be some cases where the Multiple Projectile (like a shotgun) effect would be useful, or even a high rate of fire to take advantage of the to-hit bonus even if it craters your spell success roll, to get a Hail Mary effect on a massive attack.

Hmmm....two different ways to make this work. Thanks guys! So what if we decided:
a) to go with a One-time effect of the spell cast, and
b) focused on the FP cost to create an additional 1 to 4 arrows/bolts.
c) And that the additional arrows would do exactly the same damage as the original
d) without any extra (or reduced) Recoil...

How would that change things?

[ehrbar]

Originally Posted by thom

As I see it, this is a One-time effect (I don't think it's reasonable to allow an archer to shoot multiple arrows 10+ times during a 60-second duration spell-but I could be wrong). I'm trying to determine how much FP would be spent for how many additional arrows (max of 4) for a one-time spell. Any thoughts from the Group mind?

Well, Great Haste grants Altered Time Rate for ten seconds for 5 energy. From Technomancer, Hail of Lead doubles RoF for an automatic weapon of less than 15 pounds for 2 energy, while Magic Bullet adds additional targets to a single bullet for 2 energy each.

So, for a Multimissile spell, I'm thinking 1 or 2 energy per extra, I'm just not sure which. And given usual GURPS spell design, I'd be tempted to set the limit of added missiles to either the caster's Magery or twice the caster's Magery.

Of course, for both cost and limit that factor of two affects the power of the spell by quite a bit.

[thom]

OK, how about this:

MultiMissile Regular
This spell creates 1-3 magical duplicates of the original projectile for a ranged weapon. Roll attacks for each duplicate separately; any magical properties of the original projectile are not duplicated. The number of duplicates created depends on the caster's Magery.

Magery 1 - 2 creates one additional projectile
Magery 3 - 4 creates two additional projectiles
Magery 5 - 6 creates three additional projectile

Duration: 10 seconds (or until fired)
Cost: 1 +1 per additional projectile created (2 to 4 FP)
Prerequisites: Wizardly: Magery 2? other spells??

I'm not sure what college to put this spell in (beside Illusion), or what prerequisites it would have...

thom

[Plane]

Originally Posted by mlangsdorf

Adding the Explosive modifier to a Missile spell generally increases the energy cost from 1 FP per 1d of damage to 2 FP per 1d of damage. Explosive is a +50% modifier and so is RoF 3.

So I suggest that a spell that adds RoF 3, Rcl 3 to an existing missile weapon should cost 1 FP per 1d of damage of the original attack.

Are we using the thaumatology rules for applying enhancements to spells here?

[Pursuivant]

I'd take a look at the GURPS Create Object spell as well.

A simple multimissile spell which allows duplication of small low-tech missiles isn't that far off from a missile spell like Stone Missile and should have similar casting cost and prerequisites. The only difference is that the caster casts it on the shooter or missile, who then "holds" the spell on behalf of the mage.

Potential extra missiles just "vanish" if the shooter decides not to shoot or has their shot spoiled, but the spell remains "On" until the shooter/subject gets around to shooting.

Things get tricky if you want to duplicate high-tech missiles or heavy missiles like trebuchet stones. The simple solutions are to limit missile duplication to missiles of 1 lb. or less which are hurled by hand or from a low-tech missile thrower.

College has to be Illusion & Creation since you're duplicating an existing missile at the moment it's launched.

Create Object makes it a spell for powerful mages due to the VH prerequisite and the long prereq. tree. Add Stone Missile to tie it into the Missile Spell hierarchy, but any other missile spell which creates a kinetic missile made of physical matter would work, too.


MultiMissile Regular
College: Illusion & Creation.
Creates one or more duplicates of a low-tech missile at the instant the original missile is launched. The spell's subject must be a single thrown weapon or missile designed to be hurled from a low tech (TL4 or less) missile launcher, which weighs no more than 1 lb. and which inflicts no more than three dice of basic damage (based on the shooter's or weapon's ST, as appropriate).

The mage must create the potential missiles using the rules for Missile Spells, spending energy equal to the extra dice of damage the created missiles will inflict. The mage can create a maximum number of missiles equal to three times their level of Magery, spending points of energy up to their level of Magery each turn to "build" the missiles. Each die of potential damage requires 1 point of basic energy.

For example, a mage with Magery 3 could spend 1 second and 1 point of energy to generate a single duplicate sling bullet which does 1d-1 HP, 9 seconds and 27 points of energy to generate 9 crossbow bolts which do 3d HP each, or anything in between.

If the caster is distracted or abandons the spell before it is cast energy invested in the spell is lost but, unlike typical missile spells, there is no risk of damage.

Magical or other supernatural properties of the launching weapon or the duplicated missile don't apply to the copies.

To cast the spell, the mage must touch the original missile, its intended shooter, or the weapon which used launch it. Once cast MultiMissile counts as an "on" spell until the original missile is launched or or its duration ends. If the subject doesn't shoot within the spell's duration potential duplicate missiles are lost but there are no other ill effects.

When the subject launches the original missile, all the duplicate missiles spring into being. They all share the same "to hit" modifiers as the original missile, including intended hit location, but use the rules for Rapid Fire. Treat the weapon or missile as having a temporary RoF (1 + the number of duplicate missiles created) and Rcl 1 to determine how many missiles hit. Missiles which miss the target use the usual rules for Scattering. Duplicate missiles which miss entirely vanish immediately after they land. Duplicate missiles which hit vanish as soon as they are removed from the target.

Duration: 10 seconds (or until the original missile is launched).
Cost: 1 point of energy per die of basic damage multiplied by the number of duplicate missile created, to a maximum number of missiles equal to three times the caster's level of Magery and a total number of dice of damage equal to 3 times the total number of missiles. Can't be maintained.
Time to cast: Variable. The caster may "build" the spell at energy points per turn equal to their level of Magery, until all dice of potential damage from the duplicate missiles have been added.
Prerequisites: Create Object, Stone Missile.
Items: (a) Staff, wand, clothing or jewelry. Useable only by mages. Energy cost to create: 2500. (b) Any Low-Tech Missile Launcher (e.g., Bow or Sling). Allows the weapon's user to cast the spell on any missiles launched from it. Energy cost to create: 2000. (c) Any Low-Tech missile or hurled weapon. Allows the weapon's user to create a number of duplicate missiles when the item is launched, up to the number specified by the enchanter when the item was created. Energy cost to create: 100 per duplicate missile x basic dice of damage the missile will inflict (Assume 1d for most missiles, 2d for arrows or crossbow bolts designed for high-ST weapons). (d) As above, but one use only. Energy cost to create: 20 per duplicate missile x basic dice of damage the missile will inflict.

[mlangsdorf]

Originally Posted by Plane

Are we using the thaumatology rules for applying enhancements to spells here?

I wasn't. 10 FP and -10 to skill for RoF 3 is too expensive and has too large a penalty. I reasoned by analogy with the similar modifiers on other GURPS spells.