cold evocation spells underwater

[kenfighter]

Hello everybody,

Could anyone please help me find an answer to the situation that seems to be giving me some problems?

What happens if cold Evocations spells like: Polar ray or Cone of cold are used inside water. The rules found inside the books don't seem to be covering the problem and talking about it with my friends resulted in two possible conclusions.

1) The spell will fail. The Ice was meant to be cast on the surface. Since water gives resistance to the motion of the forming ice, the newly formed particles would stick to the previously formed ones forming a mass of slowly moving ice that would just barely push the recipient. The block would then slowly float to the surface.

2) The spell will have devastating results. The ice particles would stick to anything that comes in their way including the molecules of water. In this way they would not only damage the recipient but also trap him in an air tight iceberg.

Please help me figure out this problem and how to make logical rules for that situation.

[Yora]

Depends on how you treat cold spells to work.

If you want to go by physics, the best solution would probably be that such spells actually are vortexes to the Plane of Fire that suck out the heat from everything in its path and transport it back to the Plane of Fire.
The other alternative would be that you spray super-cold liquid or gas over the target area.

In the second case, the range of such spells would be much more limited as the spray can not travel through water as easily as through air.
If you just suck out the heat, there might not be any reduction in effectiveness.

Which leaves the question if the cooled water forms a big chunk of ice or just lots of tiny crystals. Maybe it could be a very easy thing to answer for someone who knows how ice forms. But for practical reasons I would probably go with forming a slush like melting snow that completely melts and disapears again within one round or two. In that case treat the affected area as under the effect of a sleet storm spell.

[Acanous]

somehow, I misread the title as "Cold Evocation spells Underwear"
...which is much more funny and also a possibility.

ANYWHO, I believe ice takes time to crystalise, where as the ray is an instant effect. If I'm not mistaken, that means the spell will work just fine underwater, with little trails of ice crystals forming and melting in it's wake.

[Seharvepernfan]

Can't water be supercooled with turning into ice?

Also, freshwater or saltwater? I don't think saltwater freezes.

[Knaight]

Also, freshwater or saltwater? I don't think saltwater freezes.

Saltwater freezes just fine, and the latent heat of fusion by volume is actually lower due to the salinity (in that there isn't a phase change in the dissolved salt). With that said, the freezing temperature varies based on salinity, and is generally lower than 0 C. For saturated brine, it is actually 0 F.

[Yora]

It still freezes, but at lower temperatures. Not sure about huge icebergs that may have broken off from glaciers formed on land, but in the Baltic Sea we have sea ice every couple of years and there are no glaciers next to it.

[HunterOfJello]

Also, freshwater or saltwater? I don't think saltwater freezes.

Any body of water can freeze if it's cooled to an appropriate temperature. Salt water that's completely saturated with salt freezes at around -21 degrees Celsius (or -6 degrees Fahrenheit). It takes a lower temperature than freshwater, but not much lower considering how cold this magic must make things to do that much damage. Therefore, the ice would form without much difficulty and it would not be difficult at all to use ice magic underwater. (Fire magic underwater is a far different matter.)

Spells don't follow the normal rules of physics and expecting them to is just setting yourself up for a myriad of problems.

If you wanted things to be more realistic while still following the rules of magic, then I would say that once the effect is over, ice would remain in the water or it would cause the water that was there to freeze in the shape of the spell.

[Knaight]

Regarding the spells - if you can get temperature and pressure values that result from the casting somehow, you can always use this diagram:

Spoiler

Show

Note that the critical point marks the beginning of the supercritical fluid phase, which is not included on that diagram.

[Manly Man]

If you wanted things to be more realistic while still following the rules of magic, then I would say that once the effect is over, ice would remain in the water or it would cause the water that was there to freeze in the shape of the spell.

Also, if you did, say, a cone of cold, those hit by it would probably end up being frozen and begin to float to the surface, albeit with somewhat thin ice. They'd probably have to make a Strength check to break it, since even if it's not spectacularly thick, being completely hugged and surrounded like that makes any kind of movement hard; have yourself buried up to your neck in sand, and see if you can move your hands. Whether they'd take anymore damage is questionable, since holding an ice cube isn't all that painful for a good while.

Also, the visualization of a Polar Ray freezing the water is hilarious. Biggest damned popsicle you've ever seen.

[Yora]

Any body of water can freeze if it's cooled to an appropriate temperature. Salt water that's completely saturated with salt freezes at around -21 degrees Celsius (or -6 degrees Fahrenheit).

Doesn't the degree of saturation depend on the temperature? So that hot water can dissolve more salt than cold water?

[Sith_Happens]

Evocation [Cold] spells are powered by the souls of dead catgirls and therefore function identically in any medium.

[Knaight]

Doesn't the degree of saturation depend on the temperature? So that hot water can dissolve more salt than cold water?

Yes, but at some point saturation point and freezing point converge, which is the relative point. I was under the impression it was at 0 F, not -6 F, but I might be wrong here.

[karkus]

How about this; when an enemy is killed or reduced to 0 hit points, it works kind of like a Disintegrate spell, in that there is a strange effect.

What you could rule is that, if they are reduced to zero or less hit points, they are encased in ice and float slowly up to the surface. An interesting thing to try out would be to use the rules in the Earthquake spell in regards to being "pinned." Here's the section straight from the SRD:

"Pinned beneath Rubble: Any creature pinned beneath rubble takes 1d6 points of nonlethal damage per minute while pinned. If a pinned character falls unconscious, he or she must make a DC 15 Constitution check or take 1d6 points of lethal damage each minute thereafter until freed or dead."

So even if they are encased in ice and are at negative hit points, there is still a chance that they can float up to the surface, thaw, and be revived (although that would be a very small chance).

[Kelb_Panthera]

According to frostburn, ice melts at a rate of 1 cubic foot per 10 points of fire damage done.

You could houserule the reverse. For every 10points of cold damage a spell does, it creates 1 cubic foot of ice, starting at the point of contact with the water. (you did know that the surface of water breaks LoE, right?)

If you're underwater when you cast the spell, it still has its normal effect, but a thin sheet of ice forms on the affected target(s); its thickness determined as above. (mind, the 7 cubic feet that a polar ray cast at CL 20 would cover a human sized target in a film of ice not quite an inch thick, unless I'm miscalculating.)

@ knaight: Could you spoiler that chart, please? I'm getting some serious stretch from it.

[TheOOB]

What happens is the spell works as described in the book even under water. Physics doesn't normally allow for cold energy to travel in a line to someone, so the magic that does that in air also does that underwater.

[Kelb_Panthera]

What happens is the spell works as described in the book even under water. Physics doesn't normally allow for cold energy to travel in a line to someone, so the magic that does that in air also does that underwater.

Yeah, about that. Physics says there is no cold energy. Cold is the distinct -lack- of energy.

[Fiery Diamond]

According to frostburn, ice melts at a rate of 1 cubic foot per 10 points of fire damage done.

You could houserule the reverse. For every 10points of cold damage a spell does, it creates 1 cubic foot of ice, starting at the point of contact with the water. (you did know that the surface of water breaks LoE, right?)

If you're underwater when you cast the spell, it still has its normal effect, but a thin sheet of ice forms on the affected target(s); its thickness determined as above. (mind, the 7 cubic feet that a polar ray cast at CL 20 would cover a human sized target in a film of ice not quite an inch thick, unless I'm miscalculating.)

@ knaight: Could you spoiler that chart, please? I'm getting some serious stretch from it.

Source please?

[Kelb_Panthera]

Source please?

Seems I may have been only partially right. DMG pg 93, says that creatures that are completely submerged have total cover relative to creatures above water for the purpose of ranged attack rolls, be they normal or touch, unless the attacker has a Freedom of Movement effect. The surface of water does explicitly block LoE for fire spells and spell-likes and non-magical and supernatural fire don't function underwater at all.