Gas is lighter than liquid. Is it correct that a creature in gaseous form that is underwater is forced to go to the surface of the water? If so:
1) What is the speed at which this happens?
2) Is this forced movement in addition to the normal movement you get while in gaseous form?
Somewhat related question: why is there no Liquid Form spell after all these years? Or was there one in an earlier edition that never made the transition to 5E?
I suppose since your only form of movement is 10 ft of flying speed, it could be argued that you cannot do anything but fly through the air. Now, as for using it on an underwater creature, neither the spell description nor rules for movement say anything about this, so it’d go to the DM. Arguing real-world physics really doesn’t hold much weight, since per them a cloud of vapor is incapable of independent locomotion. As for why no liquid form, the only thing it offers is swim speed instead of fly speed, and underwater interactions are fairly niche in D&D.
Gas is lighter than liquid. Is it correct that a creature in gaseous form that is underwater is forced to go to the surface of the water? If so:
1) What is the speed at which this happens?
2) Is this forced movement in addition to the normal movement you get while in gaseous form?
Gas need not be lighter than liquid. (It's usually the case, but I bet there are dense gas/light liquid combinations out there on YouTube) Also, a creature under the effect of gaseous form already doesn't behave like a normal gas, much less an ideal one, so we can't assume physics will suddenly start to apply to them once they're underwater.
By the rules, a gaseous creature underwater cannot move at all -- they have no swimming speed.
If there were rules about how fast one rises when underwater like there have been in other editions (I know 2e had them, because I remember a friend making the argument that dwarves could never sink :), then they would probably apply, but 5e doesn't have any such thing as far as I can tell.
Gas need not be lighter than liquid. (It's usually the case, but I bet there are dense gas/light liquid combinations out there on YouTube)
Sadly after some searching for the best combination of chemicals that are a gas or liquid at normal room temperature and pressure revealed that the liquid was still roughly 100 times more dense than the gas. (Perfluorobutane gas and Isopentane liquid is what I found)
Also RAW suggests Gaseous Form can't move underwater because the spell says "...though it treats liquids as though they were solid surfaces". In general a creature surrounded by solid surfaces is incapable of moving.
However I probably wouldn't rule it this way. Instead I would just treat it like they had Water Walk cast on them for the purposes of what happens while they are submerged.
Gas need not be lighter than liquid. (It's usually the case, but I bet there are dense gas/light liquid combinations out there on YouTube)
Sadly after some searching for the best combination of chemicals that are a gas or liquid at normal room temperature and pressure revealed that the liquid was still roughly 100 times more dense than the gas. (Perfluorobutane gas and Isopentane liquid is what I found)
Also RAW suggests Gaseous Form can't move underwater because the spell says "...though it treats liquids as though they were solid surfaces". In general a creature surrounded by solid surfaces is incapable of moving.
However I probably wouldn't rule it this way. Instead I would just treat it like they had Water Walk cast on them for the purposes of what happens while they are submerged.
Same conclusion, because while you can't move thru liquids as a gas cloud, the water would still treat you like any other less dense material, quickly moving you to the surface.
Also RAW suggests Gaseous Form can't move underwater because the spell says "...though it treats liquids as though they were solid surfaces". In general a creature surrounded by solid surfaces is incapable of moving.
However I probably wouldn't rule it this way. Instead I would just treat it like they had Water Walk cast on them for the purposes of what happens while they are submerged.
So no movement until the creature is gaseous form reaches surface of the water. While being pushed upward by lower relative density, movement more or less straight up at 60 feet per 6 seconds (one round). That seems really fast to me.
Also RAW suggests Gaseous Form can't move underwater because the spell says "...though it treats liquids as though they were solid surfaces". In general a creature surrounded by solid surfaces is incapable of moving.
However I probably wouldn't rule it this way. Instead I would just treat it like they had Water Walk cast on them for the purposes of what happens while they are submerged.
So no movement until the creature is gaseous form reaches surface of the water. While being pushed upward by lower relative density, movement more or less straight up at 60 feet per 6 seconds (one round). That seems really fast to me.
Well, that is just how I would rule the scenario, and as I point out it isn't supported by the RAW.
However you decide to handle this scenario be aware that any movement that is the result of someone or something else moving you without using your movement, action, or reaction does not provoke an attack of opportunity. - https://www.dndbeyond.com/sources/basic-rules/combat#OpportunityAttacks
I agree with plaguescarred on the interpretation that you wouldn’t be able to move. That’s probably the RAW. However, if you are going to allow movement, there’s no reason to force the gaseous form to float to the top. For one, it’s magic; by its very nature it defies physics. Starting to apply science to the rules will probably break down very quickly. But since many people don’t like “magic did it” as an explanation, a gaseous cloud is still an intelligent being which can control its own movement. It’s not an inanimate bubble of air. Much like how a person swimming can move up and down through the water, even though a person’s density is different than that of water.
For what it's worth, I interpret the line about treating liquids as a solid surface to mean the surface of liquids, such as going from air into water rather than when you're already beneath the surface. We're looking at the same RAW. That's just how it reads to me.
The spell grants a movement of 10 ft. so it can move 10ft under water. But the water forces it up at a rate of 10ft. So at best the character who started the spell effect while underwater could at best use their 10ft movement to stay in place(at depth) underwater. ( and be pushed by the current) Or they can use their movement to move 10 sideways in the water but the water at the same time moves them upward 10 feet. They would go diagonally upward in the water.
Essentially they can never go down into the water so if they were outside the water it would act as a soft surface they could not penetrate.
I would probably rule that the water would be difficult terrain so half movement. Sure RAW it is probably no movement, given it says your only means of movement are a fly speed and liquids treated as solid surfaces. But I would hate to just tell the player they are stuck. Though only having 5 feet of movement won’t get you far fast.
I’d rule willing creature takes 3d6 force damage, and is instantly shunted to the nearest unoccupied space that is not liquid.
This is what happens most of the time a spell or ability leaves you in the middle of a solid (maybe with slightly different damage, I don't recall), so it's a reasonable choice.
Each foot of movement costs 1 extra foot (2 extra feet in difficult terrain) when you’re climbing, swimming, or crawling. You ignore this extra cost if you have a climbing speed and use it to climb, or a swimming speed and use it to swim.
If you are flying, you are not doing any of those things. The question is whether you can fly underwater, and to the best of what I can find, RAW is silent on this. My natural-language inference is that if you are moving around underwater, the general rule is that you are swimming. This case is interesting because gaseous form specifically states that your only form of movement is flying, so if you are moving, you can only be flying. I think any of these conclusions are reasonable enough, based on the rules we have and the absence of rules we don't have:
Your speed is 10', and you are flying, not swimming (specific > general). You cannot break the water's surface, as it is treated as a solid surface.
Water is treated as a solid surface throughout, so you cannot move at all while in gaseous form underwater.
There is no rule for flying underwater, so flying underwater is considered swimming. Gaseous form doesn't allow swimming, so you cannot move underwater while in gaseous form.
There is no rule for flying underwater, so flying underwater is considered swimming. 1' costs 2' unless you have a swim speed, even though you are flying.
I ranked them in the order of which they seem to me to best respect RAW and the overlap of the two rules concerning movement. Buoyancy and taking force damage/being shunted are creative ideas worthy of consideration at the table, but I do not find them to be at all supported by RAW.
I ranked them in the order of which they seem to me to best respect RAW and the overlap of the two rules concerning movement. Buoyancy and taking force damage/being shunted are creative ideas worthy of consideration at the table, but I do not find them to be at all supported by RAW.
Although shunting isn't a general rule, it is a common rule. It is true that nothing about gaseous form recommends it, and nothing generally recommends being shunted when stuck in a solid, but the alternate of being trapped for an hour inside a liquid with no way to breathe is pretty bad. (Note the spell also doesn't say breathing is altered at all either.)
I think the worst ruling a DM could make is to turn a spell like gaseous form into a protracted automatic kill. If you are shunted, that's probably fine. If you are entombed but survive until the end of the spell, that's probably fine. If you suffocate that's the no fun option.
I mean two miles of water in an hour is a long distance, so cut the trip short, take a bit of pain for the quickness, and if that’s not enough to get you out of the fire, and back into the frying pan, 3d6 force till spell ends means GF might not have been the best idea.
Gas is lighter than liquid. Is it correct that a creature in gaseous form that is underwater is forced to go to the surface of the water? If so:
1) What is the speed at which this happens?
2) Is this forced movement in addition to the normal movement you get while in gaseous form?
Somewhat related question: why is there no Liquid Form spell after all these years? Or was there one in an earlier edition that never made the transition to 5E?
I suppose since your only form of movement is 10 ft of flying speed, it could be argued that you cannot do anything but fly through the air. Now, as for using it on an underwater creature, neither the spell description nor rules for movement say anything about this, so it’d go to the DM. Arguing real-world physics really doesn’t hold much weight, since per them a cloud of vapor is incapable of independent locomotion. As for why no liquid form, the only thing it offers is swim speed instead of fly speed, and underwater interactions are fairly niche in D&D.
Gas need not be lighter than liquid. (It's usually the case, but I bet there are dense gas/light liquid combinations out there on YouTube) Also, a creature under the effect of gaseous form already doesn't behave like a normal gas, much less an ideal one, so we can't assume physics will suddenly start to apply to them once they're underwater.
By the rules, a gaseous creature underwater cannot move at all -- they have no swimming speed.
If there were rules about how fast one rises when underwater like there have been in other editions (I know 2e had them, because I remember a friend making the argument that dwarves could never sink :), then they would probably apply, but 5e doesn't have any such thing as far as I can tell.
Sadly after some searching for the best combination of chemicals that are a gas or liquid at normal room temperature and pressure revealed that the liquid was still roughly 100 times more dense than the gas. (Perfluorobutane gas and Isopentane liquid is what I found)
Also RAW suggests Gaseous Form can't move underwater because the spell says "...though it treats liquids as though they were solid surfaces". In general a creature surrounded by solid surfaces is incapable of moving.
However I probably wouldn't rule it this way. Instead I would just treat it like they had Water Walk cast on them for the purposes of what happens while they are submerged.
Same conclusion, because while you can't move thru liquids as a gas cloud, the water would still treat you like any other less dense material, quickly moving you to the surface.
So no movement until the creature is gaseous form reaches surface of the water. While being pushed upward by lower relative density, movement more or less straight up at 60 feet per 6 seconds (one round). That seems really fast to me.
Well, that is just how I would rule the scenario, and as I point out it isn't supported by the RAW.
However you decide to handle this scenario be aware that any movement that is the result of someone or something else moving you without using your movement, action, or reaction does not provoke an attack of opportunity. - https://www.dndbeyond.com/sources/basic-rules/combat#OpportunityAttacks
Since a creature in Gaseous Form treats liquids as though they were solid surfaces, i'd say it's entombed with no way to move.
I would say the creature in gaseous form is capable of "flying" at half speed underwater.
EDIT: Actually, this is not true. Each foot of movement costs 2 when swimming, unless you have a swim speed. In this case, you are specifically flying, not swimming. Even though you are underwater, I don't believe any penalty would apply.
"Not all those who wander are lost"
I agree with plaguescarred on the interpretation that you wouldn’t be able to move. That’s probably the RAW.
However, if you are going to allow movement, there’s no reason to force the gaseous form to float to the top. For one, it’s magic; by its very nature it defies physics. Starting to apply science to the rules will probably break down very quickly. But since many people don’t like “magic did it” as an explanation, a gaseous cloud is still an intelligent being which can control its own movement. It’s not an inanimate bubble of air. Much like how a person swimming can move up and down through the water, even though a person’s density is different than that of water.
For what it's worth, I interpret the line about treating liquids as a solid surface to mean the surface of liquids, such as going from air into water rather than when you're already beneath the surface. We're looking at the same RAW. That's just how it reads to me.
"Not all those who wander are lost"
I would keep it simple.
The spell grants a movement of 10 ft. so it can move 10ft under water.
But the water forces it up at a rate of 10ft.
So at best the character who started the spell effect while underwater could at best use their 10ft movement to stay in place(at depth) underwater. ( and be pushed by the current)
Or they can use their movement to move 10 sideways in the water but the water at the same time moves them upward 10 feet. They would go diagonally upward in the water.
Essentially they can never go down into the water so if they were outside the water it would act as a soft surface they could not penetrate.
I would probably rule that the water would be difficult terrain so half movement. Sure RAW it is probably no movement, given it says your only means of movement are a fly speed and liquids treated as solid surfaces. But I would hate to just tell the player they are stuck. Though only having 5 feet of movement won’t get you far fast.
EZD6 by DM Scotty
https://www.drivethrurpg.com/en/product/397599/EZD6-Core-Rulebook?
I’d rule willing creature takes 3d6 force damage, and is instantly shunted to the nearest unoccupied space that is not liquid.
This is what happens most of the time a spell or ability leaves you in the middle of a solid (maybe with slightly different damage, I don't recall), so it's a reasonable choice.
If you are flying, you are not doing any of those things. The question is whether you can fly underwater, and to the best of what I can find, RAW is silent on this. My natural-language inference is that if you are moving around underwater, the general rule is that you are swimming. This case is interesting because gaseous form specifically states that your only form of movement is flying, so if you are moving, you can only be flying. I think any of these conclusions are reasonable enough, based on the rules we have and the absence of rules we don't have:
I ranked them in the order of which they seem to me to best respect RAW and the overlap of the two rules concerning movement. Buoyancy and taking force damage/being shunted are creative ideas worthy of consideration at the table, but I do not find them to be at all supported by RAW.
"Not all those who wander are lost"
Although shunting isn't a general rule, it is a common rule. It is true that nothing about gaseous form recommends it, and nothing generally recommends being shunted when stuck in a solid, but the alternate of being trapped for an hour inside a liquid with no way to breathe is pretty bad. (Note the spell also doesn't say breathing is altered at all either.)
I think the worst ruling a DM could make is to turn a spell like gaseous form into a protracted automatic kill. If you are shunted, that's probably fine. If you are entombed but survive until the end of the spell, that's probably fine. If you suffocate that's the no fun option.
Gaseous Form requires a willing target, so nobody is getting sucker-punched by this spell.
"Not all those who wander are lost"
True enough, but that begs the question, who would be willing underwater? No possibility seems something that you'd want to happen.
I mean two miles of water in an hour is a long distance, so cut the trip short, take a bit of pain for the quickness, and if that’s not enough to get you out of the fire, and back into the frying pan, 3d6 force till spell ends means GF might not have been the best idea.