Orb Spells Conjuring Real Acid or Fire

[Icelander]

I'm looking to benchmark the most damage that non-magical acid or fire that could fit in a 3-inch diameter orb could do. In order to bypass the magical protections of foes, conjurers like to use their magic to create or summon a non-magical hazardous material, which they encase in a magical orb that is then thrown at the foe.

Yes, almost exactly like GURPS Fireball or other Missile spells.

The spells that exist in the source material include:

Orb of Acid
Orb of Cold
Orb of Electricity
Orb of Fire
Orb of Force
Orb of Sound

While I have no objection to these spells working to bypass the magic resistance of near-impenetrable magical protections, I do want the 'real' acid, fire or other stuff to have realistic properties. As they are not magical substances or energy, they do not work merely like simplistic spells, they work exactly as if some scientific process could isolate them into a 3-inch diameter sphere and then cause them to be released at a target. That's almost exactly a half pint (or 0.23 L for those with scientific mindsets).

I realise that, realistically, not all of these are created equally. Especially the 'Sound' part is hard to do realistically and might end up being a distraction device that is less useful in combat than the other spells. Equally, I doubt that without fantasy physics, there is much utility in 'Cold' as a weapon, though I hope that 0.23 L of something at a temperature of absolute zero might cause interesting effects when it reacts with atmosphere at room temperature, not to mention human skin.

Two of the most straightforward might be Acid and Fire.

Assuming some extremely powerful acid, what would be the realistic effects?

And assuming intensely hot flaming material, perhaps plasma or burning gas under fierce pressure, (though not perhaps under as much pressure as in the sun), what is realistic for the fire? If not actually from the sun, what would be a realistic fire effect from 0.23 L of very hot flaming gas, perhaps kept under some pressure?

The game system where the spells are from has them do 7d to 15d damage to one target, depending on the level of the caster. I'm trying to figure out if that's wildly inappropriate and I suspect that at least the acid will require modification, not doing its full damage quite instantly.

[Polydamas]

Originally Posted by Icelander

I'm looking to benchmark the most damage that non-magical acid or fire that could fit in a 3-inch diameter orb could do. In order to bypass the magical protections of foes, conjurers like to use their magic to create or summon a non-magical hazardous material, which they encase in a magical orb that is then thrown at the foe.

Yes, almost exactly like GURPS Fireball or other Missile spells.

While I have no objection to this working, even against creatures with near-impenetrable magical protections, I do want the 'real' acid or fire to have realistic properties. As they are not magical substances or energy, they do not work merely like simplistic spells, they work exactly as if some scientific process could isolate them into a 3-inch diameter sphere and then cause them to be released at a target.

That's almost exactly a half pint (or 0.23 L for those with scientific mindsets).

Assuming some extremely powerful acid, what would be the realistic effects?

And assuming intensely hot flaming material, perhaps plasma or burning gas from the sun, what is realistic for the fire?

The game system where the spells are from has them do 7d to 15d damage to one target, depending on the level of the caster. I'm trying to figure out if that's wildly inappropriate and I suspect that at least the acid will require modification, not doing its full damage quite instantly.

Maybe looking at how much damage is required to annihilate say a Hand or a Foot would be a good benchmark?

I don't think that hit points in D&D-based systems can be equated to hit points in GURPS at all. Spells in those systems do damage based on how high level they are and how much damage they have always done (some players get really attached to "a longsword does 1d8 and costs 15 gp"!), not because of some real-world benchmark, and hit points represent more different things than they do in GURPS.

Kromm has said in the FAQ that he sees missile spells as more of a ball of magical force which burns, shocks, melts, etc. as a side effect.

[Polydamas]

Also, my assumption would be that a world like Faerun where people throw around D&D-style attack spells is nothing like our universe under the hood (it has multiple dimensions, immortal beings and Flame Strike spells after all!) So I would not haul out a chemistry textbook and try to estimate the greatest possible rate at which acid could dissolve organic matter, because matter in that setting is made out of Earth, Water, Fire, and Air not carbon and nitrogen, but start on the premise that a spell like that should be able to annihilate a small extremity, despite tough materials (DR, Temperature Tolerance) or armour, possibly over the course of a few seconds.

[Icelander]

Originally Posted by Polydamas

Maybe looking at how much damage is required to annihilate say a Hand or a Foot would be a good benchmark?

I don't think that hit points in D&D-based systems can be equated to hit points in GURPS at all. Spells in those systems do damage based on how high level they are and how much damage they have always done (some players get really attached to "a longsword does 1d8 and costs 15 gp"!), not because of some real-world benchmark, and hit points represent more different things than they do in GURPS.

Kromm has said in the FAQ that he sees missile spells as more of a ball of magical force which burns, shocks, melts, etc. as a side effect.

Fair enough.

I should clarify that I'm not trying to match the D&D damage, necessarily. I'm trying to come up with a realistic GURPS damage (and any other realistic side-effects) that fits the described effect, i.e. conjuring non-magical fire or acid into a magical orb 3-inch in diameter, throwing that orb at someone, at which point it ceases to exist and the contents take effect on the target.

Basically, what is the most damage that 0.23 L of actual, really existing (no matter how rare) acid could do?

It's okay if it wouldn't just do ordinary damage, in fact, I'm sort of counting on it having a few Cycles of corrosive damage and maybe some toxic side effects, a brief cloud of hazardous fumes, etc. Just, what is the most hurt that you could derive from 0.23 L of real-world acid, what kind of acid would that be and what would be all the ramifications? It can be stored under pressure, as long as the pressure isn't great enough so that the bulk of the actual damage doesn't come from an explosion caused by the pressure differential, but remains caused by acid.

And then the same thing, for fire. How much damage and with what kind of realistic physical ramifications? And it would have to be still something that could reasonably be referred to as 'fire', not a nuclear reaction or something like that, but it could be an intensely hot part of a fire produced under extreme circumstances, with the flaming gases still extremely dangerous a couple of seconds after being removed from there and put into the magic orb.

[Icelander]

Originally Posted by Polydamas

Also, my assumption would be that a world like Faerun where people throw around D&D-style attack spells is nothing like our universe under the hood (it has multiple dimensions, immortal beings and Flame Strike spells after all!) So I would not haul out a chemistry textbook and try to estimate the greatest possible rate at which acid could dissolve organic matter, because matter in that setting is made out of Earth, Water, Fire, and Air not carbon and nitrogen, but start on the premise that a spell like that should be able to annihilate a small extremity, despite tough materials (DR, Temperature Tolerance) or armour, possibly over the course of a few seconds.

Again, most attack spells work pretty magically in Faerun.

These specific ones bypass protections from magical effects, at the cost of being just normal physical reactions. So, while 'normal' fireballs and acid arrows in D&D-land might exhibit some pretty non-standard physics, the conceit of these special orb spells is that they work using real-world physics, as soon as the magical orb blinks out of existence.

[Anaraxes]

For attacking humans, you probably want hydrofluoric acid. It both damages because it's an acid (as in visible tissue destruction and necrosis, classic "HP damage"), but it's also poisonous and easily absorbed through the skin and through layers of fat. Vapors cause eye damage, inhaled lung damage; absorbed, it can combine with bodily calcium and magnesium and cause cardiac arrest along with liver and kidney failure.

People in the real world rarely categorize hazards in game terms (X damage per 250 ml or X% chance of death by inhalation when a pint was spilled within two meters), but HF exposure can be lethal with 5% exposure of body surface area, even though it's most hazardous when inhaled or ingested.

(Overview) That overview has some links to PubMed articles with case studies that might give you more details if you have access to the body of those papers.

[Polydamas]

Ok, wow! Every single D&D-style protection spell I know is "protection from fire" or "stops the first 15 points of fire damage from one attack" not "protection from magical fire." I can see that being useful against effects like GURPS' Force Shield which block mundane or magical effects but not both ...

Like I said, assuming that these spells can annihilate a Hand or Foot seems a good baseline for estimating damage.

[Icelander]

Originally Posted by Polydamas

Ok, wow! Every single D&D-style protection spell I know is "protection from fire" or "stops the first 15 points of fire damage from one attack" not "protection from magical fire." I can see that being useful against effects like GURPS' Force Shield which block mundane or magical effects but not both ...

D&D monsters tend to have Magic Resistance/Spell Resistance, which stops damaging spells as well as others. Against something with high MR/SR, using any form of magical attack that relies on magical fire or any other magical energy to cause damage is mostly useless.

Originally Posted by Polydamas

Like I said, assuming that these spells can annihilate a Hand or Foot seems a good baseline for estimating damage.

Ok, how are you calculating that?

Would a 3-inch orb full of ultra-strong acid be equally dangerous as a 3-inch orb full of superhot flame?

Would their effects take place over an equivalent time frame?

[Polydamas]

Originally Posted by Icelander

Ok, how are you calculating that?

Would a 3-inch orb full of ultra-strong acid be equally dangerous as a 3-inch orb full of superhot flame?

Would their effects take place over an equivalent time frame?

Well, 3", the area which these spells affect, is about the diameter of a closed fist. I don't have a hard time believing that if you exposed a severed hand to the blast of a large rocket, or dropped it into lava, after a second it would be random scraps of oxidized carbon.

[Icelander]

Originally Posted by Polydamas

Well, 3", the area which these spells affect, is about the diameter of a closed fist. I don't have a hard time believing that if you exposed a severed hand to the blast of a large rocket, or dropped it into lava, after a second it would be random scraps of oxidized carbon.

Fair enough.

I imagine that once the magical orb containing them vanishes, the (most likely pressurised) fiery gases or hydrofluoric acid will expand and probably react with the atmosphere in interesting ways.

The fire should flash out quickly, in the absence of the kind of conditions that are usually required for sustaining extremely hot flames. In the process, though, it should probably inflict deep third degrees burns on whatever it hits and it's likely that in reacting to the oxygen around it, it will cause less intense, but more widespread burns to areas of the target not directly impacted. As normal for burning attacks, this might well ignite secondary fires, but those will be much less intensely hot.

All in all, causing multiple dice of burn damage to a target seems plausible enough for 0.23 L of something in the process of rapid and superheated combustion. But what are sensible limits to the damage for such a small volume and/or, at what point would momentarily compressing the materials inside an intensely hot fire make the reaction when decompressed be primarily some other form of damage than burning?

Late Medieval furnaces do 3d burn per second, but I'm not sure how much exposure is involved. Is that sticking a limb in there or the contents being up ended on someone? Or being engulfed entirely inside a human-sized one?

Kromm did state in a post somewhere something about more advanced blast furnaces of our modern technology being anywhere up to 6dx5 burn or more, so that being completely engulfed in such fire could pretty much take a human to -5xHP in less than a second.

What I want to avoid is assigning a damage value that can't be reached by anything that obeys actual physics, can fit in a 3-inch orb and still behaves in a manner that it makes sense to call 'fire' when the magical orb unleashes it.

I mean, I don't have any idea what would happen if 0.23 L of plasma from the sun were magically transported into contact with oxygen and a person. Would there be some sort of huge explosion levelling a city block, a smaller explosion like a concussion grenade or would there just be a flash of intense heat and fire as the comparatively tiny amount of material burned out, leaving lethal burns behind in a fairly localised target area, no larger than a thpical person?