casting spells where you don't know the cost like Counterspell

[Plane]

Sometimes the cost of a spell you're casting depends on the cost of some other spell you're interacting with.

Counterspell (B250) being the best example - half the cost. It'd apply to Suspend Spell but there cost is less of an issue since it's merely 10%

So... let's say an Ally is suffering some sort of IQ penalty from "Foolishness" (also on B250) which costs 1-5 energy depending on the strength of effect.

I'll call -2 to IQ "Foolishness 2" (costs 1 energy to counterspell) and -4 to IQ "Foolishness 4" (costs 2 energy to counterspell) for this example.

Am I going to know whether I'm trying to counter Fool2 or Fool4?
Whether 1 or 2 energy is required?

- -

Or actually - would I necessarily even know to cast "Counterfoolishness" and that it wasn't some other spell affecting my ally?

If for example they were performing at -2 to skill, that could be caused by Fool2's -2 IQ, but it could also be caused by "Forgetfulness" targeting one of the prereqs for that skill.

So basically if I know they're being affected by magic which is compromising their mind, can I just counterspell and the spell automatically chooses "Counterfool" or "Counterforget" depending on what is approriate, or would the caster have to choose whether it's Counterfool or Counterforget?

- -

Basically to know in the first place your ally is magically debuffed at all (ie the IQ penalty, assuming you notice those easily, isn't from a lack of sleep or being tipsy) seems like something Magery doesn't really give you (that's just for detecting magic items, not active spells)

Identify Spell (B249) could identify all spells in a single go, so it seems like something we're assumed to set up for using Counterspell?

This seems like IS would tell you whether it's Foolishness or Forgetfulness, but I'm not sure if it would tell me whether it's Fool2 vs Fool4 though.

Should IS also tell you the effect/energy put into the spell and how strong it is?

[Farmer]

You don't have to choose between 2 different spells. You just added that in, but it's not what's happening. It's 1 spell - Foolishness. The power of it is the variable, not the spell. You must also know the spell in order to counter it, so you know it. You cast Counterspell and if you have enough power it takes however much it takes to work.

If you want a game description, as you cast it you can then feel the power of it and how much effort you need to apply to remove it, and so you channel the right amount.

Don't overcomplicate things, like making different power levels into multiple spells such that you need to pick between them. There's nothing about that in the spell or Counterspell.

[Varyon]

My inclination would be to say Counterspell automatically analyzes the spell in some way - it won't tell the caster what spell it is, only a) if they know it and b) what the energy cost is going to be. Perhaps the mage starts casting Counterspell, but the spell he/she is trying to counter isn't one the mage knows. The spell fizzles, and the mage says "This was done with magic I have no knowledge of, and is beyond me to simply remove; we will have to try another approach." Or the mage starts casting Counterspell, but it was a high-energy spell and the mage is low enough on FP to be unable to safely counter it. Again, the spell fizzles, and this time the mage says "This was done with powerful magic, and I am depleted. Let me rest, and I'll be able to remove it once my reserves have replenished."

[Anthony]

The Banish spell discusses this: "The caster will not know in advance how much energy the spell will require, and may fall unconscious or even wound himself in casting the Banish." It's unclear whether this is unique to Banish or a more general rule; I recall seeing similar issues with ceremonial magic but can't find them now, so it might be a 3rd edition memory.

[Plane]

Originally Posted by Farmer

You don't have to choose between 2 different spells. You just added that in, but it's not what's happening. It's 1 spell - Foolishness. The power of it is the variable, not the spell. You must also know the spell in order to counter it, so you know it. You cast Counterspell and if you have enough power it takes however much it takes to work.

That sounds pretty dangerous though, like what if you're at 1 FP and you think you're just spending 1 FP to couner "Fool2" but it turns out there's some "Fool10" (per Magery and Effect) which costs 5 energy and you end up putting yourself down to -4 FP instead of 0 FP plus taking 4 HP damage in the process?

If there was a way to know how many levels of fool (and thus how much energy it will cost you to Counterspell it) then that sounds like it'd be a big strategic benefit in partitioning out limited energy reserves for spellcasting.

Originally Posted by Farmer

Don't overcomplicate things, like making different power levels into multiple spells such that you need to pick between them. There's nothing about that in the spell or Counterspell.

One of the things Counterspell talks about is you can cast it multiple times to take out an AE (implying 1 casting by default hits a single hex)

So it seems implied if you wanted to take out a larger AE than a single hex in a single casting that you'd have to pump in more energy and you'd negate an AE based on the energy you pumped into it.

[Plane]

Originally Posted by Varyon

My inclination would be to say Counterspell automatically analyzes the spell in some way - it won't tell the caster what spell it is, only a) if they know it and b) what the energy cost is going to be. Perhaps the mage starts casting Counterspell, but the spell he/she is trying to counter isn't one the mage knows. The spell fizzles, and the mage says "This was done with magic I have no knowledge of, and is beyond me to simply remove; we will have to try another approach."

If Counterspell was this flexible (automatically detects the right spell to counterspell) then why does a Spell Stone of Counterspell (M60-61) require specifying which spell to counter?

Originally Posted by Varyon

Or the mage starts casting Counterspell, but it was a high-energy spell and the mage is low enough on FP to be unable to safely counter it.

Again, the spell fizzles, and this time the mage says "This was done with powerful magic, and I am depleted. Let me rest, and I'll be able to remove it once my reserves have replenished."

So are you thinking the energy would be wasted, or that the energy doesn't get spent at all if you don't have enough?

The closest rule I can remember to this is M14's Burning HP:

Should a failed HT roll indicate that you have died, you do not actually spend the HP. Instead, you fall unconscious.

It's actually a pretty weird one because then you can do weird stuff like fish for critical successes (0 cost) doing high-energy spells that would 100% kill you otherwise (meaning you spend nothing if you don't get a critical success).

It's one of those things that could probably use a tweak, though the penalty per HP burned probably holds it in check except for very high-skill casters.

Originally Posted by Anthony

The Banish spell discusses this:
"The caster will not know in advance how much energy the spell will require, and may fall unconscious or even wound himself in casting the Banish."
It's unclear whether this is unique to Banish or a more general rule

Given this has a variable cost based on the character point total of the demon you're banishing, it makes me naturally compare it to the Elemental Spirit Spells...

With the Summon (Air) Elemental (M27) it says "The caster determines the elemental’s power level by the amount of energy he spends" for example, for how M28's "1 point per 10 character points used to build" works.

This is presumably also how Create (Air) Elemental works on the next page, except the caster gets more design control over how the character points are spent (not absolute, but better than the GM fiat of Summon)

The real question here is Control (Air) Elemental. It also has a cost variable to the CP total, but it doesn't mention how you determine the energy spent.

The outcome of a failed Summon (you spend the energy, nobody comes) is probably not going to be as bad as a failed control (like if you were trying to stop a rampaging elemental).

Control Elemental seems to give some basis for estimating the CP total (a 0-cost Information Spell used to estimate it's 4 attributes of IQ/ST/DX/HT) but that won't necessarily be wildly accurate since if there's other stuff like DR or HP variance the spell won't let you know those things.

[Varyon]

Originally Posted by Plane

If Counterspell was this flexible (automatically detects the right spell to counterspell) then why does a Spell Stone of Counterspell (M60-61) require specifying which spell to counter?

I don't have GURPS Magic, and don't know how a Spell Stone functions. But I'm going to assume it's basically an object that lets the user either cast a spell he/she doesn't know or - based on a little digging online - casts the spell itself, using FP invested into it when it was made (one of the online mentions was using it as an energy store, with it casting Lend Energy on the user). In either case, it makes sense that a preprogrammed spell (akin in some ways to an RPM Charm) couldn't be adjusted on the fly, while a freshly-cast spell could be.

Originally Posted by Plane

So are you thinking the energy would be wasted, or that the energy doesn't get spent at all if you don't have enough?

Probably either no cost or a nominal cost of 1 FP (reduced by high skill). That, or however you handle a spell when the casting fails - the character is essentially aborting the spell to avoid spending the full amount of FP (but this is different from a true failure, in that it wouldn't become a Critical Failure in Very High Mana or similar).

Originally Posted by Plane

It's actually a pretty weird one because then you can do weird stuff like fish for critical successes (0 cost) doing high-energy spells that would 100% kill you otherwise (meaning you spend nothing if you don't get a critical success).

Sure, you can do that, so long as the GM doesn't step in and say "No, that's clearly not how this is supposed to work, stop it or karma will stop it for you." Of course, all those crit-fishing rolls also have a chance of catching the wrong kind of crit and having the spell explode in your face (in a situation like that, I'd absolutely rule that a Critical Failure kills you outright, overriding whatever safety mechanism typically results in you merely falling unconscious, in lieu of - or perhaps in addition to - a roll on the Critical Spell Failure Table).


Of course, this is all along the lines of a purely theoretical "This is how I would handle it," not necessarily how it's all supposed to work.

[Plane]

Originally Posted by Varyon

I don't have GURPS Magic, and don't know how a Spell Stone functions. But I'm going to assume it's basically an object that lets the user either cast a spell he/she doesn't know or - based on a little digging online - casts the spell itself, using FP invested into it when it was made (one of the online mentions was using it as an energy store, with it casting Lend Energy on the user). In either case, it makes sense that a preprogrammed spell (akin in some ways to an RPM Charm) couldn't be adjusted on the fly, while a freshly-cast spell could be.

The thing about on-the-fly adjustments is either we assume the caster knows which spell they are adjusting to (meaning that have some way of knowing what it was, making Identify Spell less important) or the spell itself adjusts to suit what it's countering.

Like if it's the latter case - after a successful counterspell do you even know which spell you just countered, or just that "I countered some unknown spell that cost 1 or 2 energy by spending 1 energy" ?

If it worked like that it seems strange your skill level in it would even matter (as you don't even know where you're applying your knowledge) or that you'd need to preprogram into spellstones.

Originally Posted by Varyon

Sure, you can do that, so long as the GM doesn't step in and say "No, that's clearly not how this is supposed to work, stop it or karma will stop it for you."

Did some digging looks like Kromm addressed this in 2005 http://forums.sjgames.com/showpost.p...8&postcount=12

"When you burn HP to cast a spell, you always lose the HP. It's only FP costs that are reduced to 1 FP on a failure."

We could probably assume that this also applies to cases like reducing to 0 FP on a critical success.

This seems to conflict with the idea that a failed HT roll to survive HP loss results in not burning the HP though... or at least there's a complicated order of operations involved.

Maybe we could view this as a separate ability that Magery gives?

Something like...

1) as a free action that can be done at any time, you may ATTEMPT to sacrifice any amount of HP that would not automatically kill you (-5x HP for most, -10xHP for immortals)
2) if this would reduce you to a negative multiple of HP (a HT roll to avoid dying) make that HT roll
3) if that HT roll fails, your attempt to burn the HP fails, try again next turn! If it succeeds, you burn the HP and continue to step (4)
4) the sacrificed HP will temporarily give you Energy Reserve (Magic) equal to the amount of HP burned
5) that ER only lasts 1 second, and can only be spent on one spell
6) that one spell suffers a casting penalty equal to the HP you burned

This seems like it'd let you know if you got the temporary ER for spellcasting and whether or not you'd be able to complete the spell though, meaning if you failed to swap the HP for the ER (because the HT roll to survive failed) then you could abandon casting the spell and not waste any of the FP you were contributing to it, assuming you were doing a combo of FP+HP to cast it.

That's a pretty big advantage and I'm unsure if the rules are meant to operate that way. I think if you abandon casting a spell midway then it costs 0 energy, so maybe it does work that way?

- - -

I've never actually seen this defined as an ability. T25 has the "Injurious Magic" limitations where it becomes mandatory to use this, but I can't recall anywhere talking about mages who can't use this option for spellcasting.

Even T24's "External Energy Only" just says "can never use your personal FP for magic" and doesn't address stuff like HP or ER

Originally Posted by Varyon

Of course, all those crit-fishing rolls also have a chance of catching the wrong kind of crit and having the spell explode in your face (in a situation like that, I'd absolutely rule that a Critical Failure kills you outright, overriding whatever safety mechanism typically results in you merely falling unconscious, in lieu of - or perhaps in addition to - a roll on the Critical Spell Failure Table).

That's the weird thing though - if you don't actually have enough energy to successfully cast a spell, then you can't succeed/fail (crit or otherwise) at casting it.

So if something prevents you from getting the required energy to complete the spell (like failing the HT roll to survive per B237 or M8) then it can't even fail.

It'd probably be similar to getting "spoiled" like the "Distraction and Injury" rules but I'm not aware of that counting as a fail or crit fail.

Having spoiled spells roll on the crit fail table does sound pretty cool though, but it opens a weird window where you can unleash full-power magical effects without spending the energy you normally would.

If it were just interrupted spells I'd say a cool house rule would be to roll skill anyway, except it would be like:

1) crit success = no energy wasted, just no effect
2) normal success = 1 energy wasted, like a normal failure
3) normal failure = full energy wasted, but no crit table
4) crit fail = full energy wasted, crit fail table too

But if the reason it fails is there's actually no energy (the HP does not burn, there's no FP or ER to waste) then having your spell create anyway (even if it does the wrong thing like attack an ally or buff an enemy) is pretty odd.

[Pursuivant]

As a house rule or a Perk, a mage could have a "magic fuse" that cuts out after they burn a certain amount of FP or HP. They still lose the energy invested up to that level, but no more.

That means that spells like Banish or Counterspell just fail rather than putting the mage into a coma.

[Plane]

Banish explicitly calls out accidental high-spending unlike others though, which seems to imply you'd know what you spent on other stuff like counter