How to swim on lava


Advice

Shadow Lodge

One of my players has an ability where she's immune to fire as an EX ability

Late game in my plans I was going to have them recover a mystic artifact that holds the world together from a pillar in the center of a lake of lava (guarded by a dragon of course)

Now the magic of the area prevents flight and teleportation (and induces blight burn sickness in certain areas)

But she could simply swim or walk across

But lava's heavy, you can't just swim through it without significant difficulty
And walking on it would be similarly difficult due to it's flowing nature

Soooo

I need advice on how to let them get the artifact


I'd say if she has (Ex) Fire Immunity and a decent strength score, then she does just swim through it like a big pool of syrup. Make it slow going, include some fire-immune wildlife that the party needs to hold off while she gets it, but don't over complicate the process.


Treat it just like swim but up the DC because of it's viscosity.


graystone wrote:
Treat it just like swim but up the DC because of it's viscosity.

There was a mythbuster episode on this - swimming through custard or similar. In theory the viscosity shouldn't matter - but in practice it did. ISTR they got better after a few attempts. Suggests a DC change might be appropriate (at least while unfamiliar).

Shadow Lodge

Ok.
How much should I up the DC by and what fire immune critters should an individual lvl 12-15 character fend off while swiming?


One trouble is bouyancy. It's a lot of work to sink in molten rock, since you have to displace your volume of lava.

Shadow Lodge

I was thinking of having her weighed down in a suit of armor and maybe be carrying everyone's weapon so, encumbrance would also be an issue if they go that route


Lord Foul II wrote:

Ok.

How much should I up the DC by and what fire immune critters should an individual lvl 12-15 character fend off while swiming?

Hmmm... Well, do the characters know that there is going to be a lava swim? If so, they could practice in some thick mud to get used to the difference. that'd make a lot of difference between trying it cold turkey.

Base DC is ten. I'd double it to 20 base. From add what seems appropriate. Lava can have currents in it so you can add +5-10 for Rough/Stormy water if the number seems low or give a bonus on the try if they got practice.

Also remember that at that level they most likely have access to a spell/item that grants swim speed and that grants +8 checks and take 10 on checks. Make sure to factor those in if they can access them.

As to lave dudes...
Lava Lurker and Salamander w/ class levels are a good start.

here is a quick list of fire type creatures that can survive lava up to CR 17.

Fire Crab, Small (CR 1/2)
Lesser Fire Crab (CR 1/2)
Fire Fish (CR 1)
Fire Snake (CR 1)
Small Fire Elemental (CR 1)
Small Magma Elemental (CR 1)
Small Smoke Elemental (CR 1)
Azer (CR 2)
Fire Crab, Medium (CR 2)
Flame Drakeling (CR 2)
Thoqqua (CR 2)
Worker Thermite (CR 2)
Burning Ghat (CR 3)
Fire Drake (CR 3)
Greater Fire Crab (CR 3)
Hell Hound (CR 3)
Lava Child (CR 3)
Lava Child (CR 3)
Magmin (CR 3)
Medium Fire Elemental (CR 3)
Medium Magma Elemental (CR 3)
Medium Smoke Elemental (CR 3)
Pyrolisk (CR 3)
Smoke Mephit (CR 3)
Wyrmling Brass Dragon (CR 3)
Fire Nymph (CR 4)
Mythic Hell Hound (CR 4)
Phantom Stalker (CR 4)
Soldier Thermite (CR 4)
Brimorak (CR 5)
Drake, Flame (CR 5)
Fire Phantom (CR 5)
Large Fire Elemental (CR 5)
Large Magma Elemental (CR 5)
Large Smoke Elemental (CR 5)
Rast (CR 5)
Very Young Brass Dragon (CR 5)
Queen Thermite (CR 6)
Salamander (CR 6)
Tear of Nuruu'gal (CR 6)
Wyrmling Red Dragon (CR 6)
Brass Man (CR 7)
Burning Dervish (CR 7)
Cinder Ghoul (CR 7)
Heat Swarm (CR 7)
Huge Fire Elemental (CR 7)
Huge Magma Elemental (CR 7)
Huge Smoke Elemental (CR 7)
Magma Ooze (CR 7)
Magma Ooze (CR 7)
Magmoid (CR 7)
Oil Shark (CR 7)
Wyrmling Gold Dragon (CR 7)
Young Brass Dragon (CR 7)
Young Mist Dragon (CR 7)
Young Underworld Dragon (CR 7)
Fire Lizard (CR 8)
Genie, Efreeti (CR 8)
Juvenile Brass Dragon (CR 8)
Lava Weird (CR 8)
Seraph Genie (CR 8)
Shard Slag (CR 8)
Very Young Red Dragon (CR 8)
Young Magma Dragon (CR 8)
Ghirru (CR 9)
Greater Fire Elemental (CR 9)
Greater Magma Elemental (CR 9)
Greater Smoke Elemental (CR 9)
Hell Hound, Nessian (CR 9)
Lava Drake (CR 9)
Very Young Gold Dragon (CR 9)
Young Solar Dragon (CR 9)
Fire Whale (CR 10)
Giant, Fire (CR 10)
Hawanar Genie (CR 10)
Young Adult Brass Dragon (CR 10)
Young Red Dragon (CR 10)
Young Vortex Dragon (CR 10)
Adult Brass Dragon (CR 11)
Adult Mist Dragon (CR 11)
Adult Underworld Dragon (CR 11)
Char Shambler (CR 11)
Cinder Knight (CR 11)
Elder Fire Elemental (CR 11)
Elder Magma Elemental (CR 11)
Elder Smoke Elemental (CR 11)
Juvenile Red Dragon (CR 11)
Mythic Nessian Warhound (CR 11)
Young Gold Dragon (CR 11)
Adult Magma Dragon (CR 12)
Juvenile Gold Dragon (CR 12)
Mature Adult Brass Dragon (CR 12)
Mythic Fire Giant (CR 12)
Mythic Young Red Dragon (CR 12)
Adult Solar Dragon (CR 13)
Fire Elemental Construct (CR 13)
Wickerman (CR 13)
Young Adult Red Dragon (CR 13)
Adult Red Dragon (CR 14)
Adult Vortex Dragon (CR 14)
Mythic Elder Fire Elemental (CR 14)
Old Brass Dragon (CR 14)
Volcano Giant (CR 14)
Young Adult Gold Dragon (CR 14)
Adult Gold Dragon (CR 15)
Fire Yai (CR 15)
Mature Adult Red Dragon (CR 15)
Phoenix (CR 15)
Very Old Brass Dragon (CR 15)
Ancient Brass Dragon (CR 16)
Ancient Mist Dragon (CR 16)
Ancient Underworld Dragon (CR 16)
Mature Adult Gold Dragon (CR 16)
Ancient Magma Dragon (CR 17)
Azata, Brijidine (CR 17)
Old Red Dragon (CR 17)
Thrasfyr (CR 17)
Wyrm Brass Dragon (CR 17)

Scarab Sages

The only rule I know of that allows 'swimming' in lava is Earth Glide combined with fire immunity. But being that you are the GM you can rule it how you like.

I'd suggest allowing them to walk across if they can move 60 ft per move without a check. Such as a haste would allow.
Or if they have Air Walk or Feather Step you could maybe allow it.

The spell Water Walk specifically says it allows walking on lava.

You could throw in a magic item that is part of the dungeon that gives Water Walk with the flavor that the designer is naturally immune to fire.

Then you can throw in some type of fire immune worm creature that grabs and tries to pull its victims under the lava. But water walk automatically floats you to the surface. Would make for an interesting encounter.

Shadow Lodge

They know that the item they are looking for is called an Elemental Heart (earth or fire they aren't sure) and the area has volcanoes so they may or may not put two and two together


Would Freedom of Movement let the PC swim in lava?


Lorewalker: There are creatures that have swim speeds only in lava, like the Lava Lurker, so it seems possible to swim in it without other abilities. The Tor Linnorm can also swim in lava too.

I'll admit it's incosistant though as the Pyropiscis and Lava Drake can burrow through lava or magma. So take from that what you will.

PS to OP: I forgot about the Freedom of Movement spell. With it, they would most likely no have an increased difficulty swimming. Though there is one issue still standing. How is the PC going to see where she's going?

Shadow Lodge

Ooh I love linnorms, swapping out the dragon they were going to fight for one of them, maybe with a template or two

Re: vision. Gonna leave that up to them when they get to this point.
Just wanna have options set up depending on what they decide to do.


A Tor Linnorm would be an ugly fight for 12-15 levels as it's a CR 21. Even a Young Pod-Spawned one ranks a CR 18.

Scarab Sages

graystone wrote:

Lorewalker: There are creatures that have swim speeds only in lava, like the Lava Lurker, so it seems possible to swim in it without other abilities. The Tor Linnorm can also swim in lava too.

I'll admit it's incosistant though as the Pyropiscis and Lava Drake can burrow through lava or magma. So take from that what you will.

PS to OP: I forgot about the Freedom of Movement spell. With it, they would most likely no have an increased difficulty swimming. Though there is one issue still standing. How is the PC going to see where she's going?

The Tor Linnorm has an ability that specifically allows it to swim in Lava. And the Lava Lurker is from a module(which usually means it is not as fact checked as bestiary beasts).

But thank you for pointing them out.

Lava is called a liquid in game. But it is a weird substance in real life and poorly described in Pathfinder.

The sight issue is the same as burrowing. Oddly enough not everything that burrows has tremorsense.

Scarab Sages

graystone wrote:
A Tor Linnorm would be an ugly fight for 12-15 levels as it's a CR 21. Even a Young Pod-Spawned one ranks a CR 18.

It calls for my favorite part of GMing. Developing a specific monster for a specific encounter. Take a Linnorm you like and then adjust its numbers to be a fair fight taking the environment into account.

In the case of Linnorm you may want to alter its curse to relate to your mcguffin.


Lorewalker: Oh I agree lava/magma is poorly described in Pathfinder. It's a side effect of not many people wanting to take a dip in it. ;)

I can see both swim and burrow being possible for different reasons. As a fluid, the default is swimming IMO. [fly = gas, swim = liquid, land = on solid, burrow = through solid] However, burrow is assumed to works in dirt/sand so it's close. As far as I know, burrow rules where never made so it's hard to say how it works. And with earth glide based off of burrowing... it's a can of worms I avoid.

On the Tor Linnorm: Oh there's a lot you can do to make it fit or skew the chances. it's just that is was so far about the players weight class I figured I better say something. ;)

Shadow Lodge

I have a large group of well optimized characters for my group
I figure they'll be fine
(Plus, who ever said a hunt for artifacts was supposed to be easy?)


Lava is much denser than the human body. If you're immune to fire, you can walk across it.


Paladin of Baha-who? wrote:
Lava is much denser than the human body. If you're immune to fire, you can walk across it.

Not quite. You definitely won't sink, but I don't think you'll be doing much walking. It looks like lava can have a density of around 3100 kilograms per cubic meter. An average 80.7 kilogram human will still displace 80.7 kilograms of lava. In terms of volume, that's just over 0.026 cubic meters, or 26 liters. The average human leg takes up around 10 liters, so a human attempting to walk on lava will sink about up to their waste. And probably fall over.


Avoron wrote:
Paladin of Baha-who? wrote:
Lava is much denser than the human body. If you're immune to fire, you can walk across it.
Not quite. You definitely won't sink, but I don't think you'll be doing much walking. It looks like lava can have a density of around 3100 kilograms per cubic meter. An average 80.7 kilogram human will still displace 80.7 kilograms of lava. In terms of volume, that's just over 0.026 cubic meters, or 26 liters. The average human leg takes up around 10 liters, so a human attempting to walk on lava will sink about up to their waste. And probably fall over.

I am curious, where does one find the average volume of body parts? (It's for science, I swear)


Could they somehow cool down the surface of the lava (with a water or cold based spell) and then use acrobatics checks as to not break the weak surface. If it does break a swim check the rest of the way.


Honestly I don't think sinking while walking is an issue- sure, you *can* sink, but it's so dense and viscus that it'd be a slow process. Running, I'm even more sure you could just go on the surface.

It's standing that'd be a problem, that's where you have time to sink.


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magispitt wrote:
I am curious, where does one find the average volume of body parts? (It's for science, I swear)

Well, if one is me, one looks through the results of a 1969 air force study into aerospace medicine.

Davia D wrote:

Honestly I don't think sinking while walking is an issue- sure, you *can* sink, but it's so dense and viscus that it'd be a slow process. Running, I'm even more sure you could just go on the surface.

It's standing that'd be a problem, that's where you have time to sink.

Yeah, I can definitely see how running over the lava could give you less time to sink in. But I can also see how it could be like trying to run through tar. I doubt either of us knows enough about the physics to make anything more than a guess. So, this sounds like a good time for an experiment - anyone have a pool of lava handy?


I thought I'd read somewhere magma/lava is so heavy, it also deals crushing damage when you're submerged in it, but I can't find it anymore. Anyway, if that is correct, you can't really swim through it unless you have a lot of HP to spare.


Non Newtonian Fluids!

Something as simple as having to take a move action every round to avoid becoming stuck would make this a really difficult area. (you can run on the spot, but the "move action" means that you have to put meaningful effort to avoid sinking)

I'm thinking varying degrees here:

After 1 round you're up to your knees. It takes a standard action to free yourself.
- Disadvantage: You can't move, even 5 foot step (and maybe lose dodge bonuses to AC?)
- Advantage: Bonuses vs certain Combat Maneuvers (Bull Rush/Trip etc).

After 2 rounds you're up to your waist: It takes a full-round action to free yourself.
- Disadvantage: Definitely lose Dodge to AC, you're now considered on lower ground (enemies get bonus to attack). Probably more here, I'm just spit-balling.
- Advantage: Immune to certain Combat Maneuvers (Bull Rush/Trip etc).

After 3 rounds you're up to your chest: It takes a full-round action to get back to the point where you're up to your waist.
- Disadvantage: You're chest deep in Lava, you can't do much really. Probably taking some crushing damage, maybe fatigued while you're trapped (the lava would be literally crushing your chest).
- Advantage: I guess you're still technically immune to being tripped? Although you'd probably be considered "Prone" at this point, so it's not much of a consolation.

Remember we're talking about lava here, not normal quicksand/whatever, so there's fire etc.

You could have rules about allies helping you out making it quicker to escape (aid another not just a pathetic +2 to your escape roll).

Also for funsies: What happens to Non Newtonian Fluids in an Earthquake?

Also if you want to do your own experiments with this stuff it's just corn-starch and water. It's totally kid-safe (it should be edible assuming no one has allergies) and fun to play with as long as you don't make enough that people can drown in it ... Once they can drown in it it's more commonly referred to as "quick-sand".

EDIT: I don't actually know anything about lava, it's probably not a non-newtonian fluid, but this might give you some ideas.


Swimming on lava sounds quite difficult. Swimming in lava sounds easier.


Davia D wrote:

Honestly I don't think sinking while walking is an issue- sure, you *can* sink, but it's so dense and viscus that it'd be a slow process. Running, I'm even more sure you could just go on the surface.

It's standing that'd be a problem, that's where you have time to sink.

I doubt most people's feat can manage running in lava. Even immune it flows, is incredibly hot, and none too stable.

However, techniques and shoes designed for running on water would be many times more effective.


MrCharisma wrote:
After 3 rounds you're up to your chest

Before you reach this point, you will start to float - sinking up to your chest would require displacing an amount of lava that weighs more than you do. Although if you're carrying heavy gear or wearing heavy armor, that might make you sink a bit more. Speaking of which...

Lord Foul II wrote:
I was thinking of having her weighed down in a suit of armor and maybe be carrying everyone's weapon so, encumbrance would also be an issue if they go that route

This is probably not a good idea: just because a character may be immune to fire damage doesn't mean their gear is. If they're swimming through lava, pretty much everything they're carrying will be taking 20d6 points of fire damage per round. They might be able to reduce this - if the item is only partially submerged it will only take 2d6 damage, and some materials only take half damage from fire attacks before applying hardness. But the lava will cause problems regardless. Flammable materials may catch fire, burning items may create smoke. Items made of iron or steel won't actually get hot enough to melt ("lava can't melt steel beams") but that won't stop them from getting damaged. Basically, not a fun time.


Quentin Coldwater wrote:
I thought I'd read somewhere magma/lava is so heavy, it also deals crushing damage when you're submerged in it, but I can't find it anymore. Anyway, if that is correct, you can't really swim through it unless you have a lot of HP to spare.

Submerging shouldn't be a problem with most lava- just lay down and you'll 'float'. Even quicksand is very easy to stay on the surface on.

Thinking about it, I'd rule it as difficult terrain due to it's shifting nature, plus if someone stands in place they'll be entangled and have to 'break free' (really just work their way on the surface).

All of this with fairly normal lava flows- if there's a fast flowing lava stream, it's effectively an extra-dense avalanche even sans fire, but considering we're talking walking to begin with, I assume that's not the type of thing we're dealing with.


QuidEst wrote:
One trouble is bouyancy. It's a lot of work to sink in molten rock, since you have to displace your volume of lava.

Yup. It's not possible to swim through lava because you won't be deep enough in it in the first place unless you strap a lot of weight to yourself--and at that point you're not doing much of anything unless you're very, very strong.

Assuming they have any swim ability at all I would not roll a check, it's too different from swimming to matter. The only viable way I see to cross is via a backstroke which is why I am differentiating having any skill vs no skill. Someone with no skill at all is going to be a mess, someone who knows the backstroke (note that I would allow them to be taught it in a few hours {assuming a calm body of water for teaching} without putting a skill point towards it--the skill thus acquired would be far below what 1 skill point represents) isn't going to fare very well but I would expect them to get across eventually assuming there's no flow.

If there is a flow, though, they're going with it no matter what. They could cross while going downstream, going upstream isn't an option.


According to Paladin of Baha-who?, "lava can have a density of around 3100 kilograms per cubic meter." That is, its density is ~3.1. Water's density is defined as 1.0. Humans float (barely) in water, so a human's density is < 1.0. Therefore about 1/3 of your body is submerged when you "float" in lava.

How big is a body? Water has ~64# / cubic foot. Humans weigh about the same as water. Average human is about 120#-130#. Therefore, average human consumes ~2 cubic feet of volume.

Ways to bypass:
1) Ninja class skill Light Steps allows walking on water. Ex ability, so good even if magic is not.
2) Create Water lasts a day, and is a cantrip, so you can generate a lot in a short time. Applied to the surface, it will temporarily cool it and form a crust. You can now walk on the crust. It is still very hot, so you keep putting more water on it. GM may rule it insufficient to be effective, but might not.
3) Jumping. If it is not too far, you can jump across. My 13th level ninja/witch can reliably jump a minimum of 60' with just class skills. It is Su, so antimagic can remove the 1/2 DC effect.
4) Summon a fire or lava elemental. Let someone else clear the way.
5) Ebony Fly can fly over the lava. So can a Carpet of Flying. The figurine is better, as it might still function in an antimagic zone.
6) A Burning Skeleton can go into an antimagic area, and is immune to fire. If made from something that retains flight when animated, can even be used to carry party members across.

/cevah


Unless the lava is flowing really really fast, walking seems like the better idea here. It's probably easier to run on than cornflour, and people manage that.

Shadow Lodge

Avoron wrote:
MrCharisma wrote:
After 3 rounds you're up to your chest

Before you reach this point, you will start to float - sinking up to your chest would require displacing an amount of lava that weighs more than you do. Although if you're carrying heavy gear or wearing heavy armor, that might make you sink a bit more. Speaking of which...

Lord Foul II wrote:
I was thinking of having her weighed down in a suit of armor and maybe be carrying everyone's weapon so, encumbrance would also be an issue if they go that route

This is probably not a good idea: just because a character may be immune to fire damage doesn't mean their gear is. If they're swimming through lava, pretty much everything they're carrying will be taking 20d6 points of fire damage per round. They might be able to reduce this - if the item is only partially submerged it will only take 2d6 damage, and some materials only take half damage from fire attacks before applying hardness. But the lava will cause problems regardless. Flammable materials may catch fire, burning items may create smoke. Items made of iron or steel won't actually get hot enough to melt ("lava can't melt steel beams") but that won't stop them from getting damaged. Basically, not a fun time.

this is a very good point I hadn't thought of the damage to their armor/weapons

Ok so that's still an option they could pursue, but between the heat and the pressure the equipment would be warped and dented at best unless it's reaaaaaly sturdy

For the record
The character is a vampire who's eaten a devil fruit which grants fire immunity intrinsically

The artifact they're collecting is one that keeps the elemental plane of fire from seeping too deeply into the prime material (in the setting the walls between planes are weakened by a massive war a thousand years ago and most planes dip into the others in placesz, these artifacts are like dams keeping the planes from flooding into each other)

The magics protecting the place specifically prevent flight and any form of conjuration (whether teleportation or summoning)

The party does not have a ninja
It is much too far to jump
The decanter could work
The flaming skeleton of something like a giant turtle could work, and it'd be hilarious

Scarab Sages

Lord Foul II wrote:
Avoron wrote:
MrCharisma wrote:
After 3 rounds you're up to your chest

Before you reach this point, you will start to float - sinking up to your chest would require displacing an amount of lava that weighs more than you do. Although if you're carrying heavy gear or wearing heavy armor, that might make you sink a bit more. Speaking of which...

Lord Foul II wrote:
I was thinking of having her weighed down in a suit of armor and maybe be carrying everyone's weapon so, encumbrance would also be an issue if they go that route

This is probably not a good idea: just because a character may be immune to fire damage doesn't mean their gear is. If they're swimming through lava, pretty much everything they're carrying will be taking 20d6 points of fire damage per round. They might be able to reduce this - if the item is only partially submerged it will only take 2d6 damage, and some materials only take half damage from fire attacks before applying hardness. But the lava will cause problems regardless. Flammable materials may catch fire, burning items may create smoke. Items made of iron or steel won't actually get hot enough to melt ("lava can't melt steel beams") but that won't stop them from getting damaged. Basically, not a fun time.

this is a very good point I hadn't thought of the damage to their armor/weapons

Ok so that's still an option they could pursue, but between the heat and the pressure the equipment would be warped and dented at best unless it's reaaaaaly sturdy

For the record
The character is a vampire who's eaten a devil fruit which grants fire immunity intrinsically

The artifact they're collecting is one that keeps the elemental plane of fire from seeping too deeply into the prime material (in the setting the walls between planes are weakened by a massive war a thousand years ago and most planes dip into the others in placesz, these artifacts are like dams keeping the planes from flooding into each other)

The magics protecting the place specifically...

You way want to suggest to them to get dragon armor from a dragon with fire breath. It will have natural fire immunity too. So at least the armor will survive as well as them.

Shadow Lodge

But dragon hide wouldn't be very heavy

Maybe rhemorez hide? Chiten is heavy right?

Or maybe just hope they get "lucky" regarding their rolls on their unchained magic item generation

Grand Lodge

Not sure this has already been mentioned but...

Assuming the party finds means of swimming and can make the decided DCs, how does vision work when in lava? Like water? Limited to 10ft? I have trouble imagining being able to see easily while submerged, though that may get in the way of fun or interesting encounters...


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Important note: Lava is a non-Newtonian fluid.

You could run across it in the same way that people run across pools filled with cornstarch/water mixture.


Magic the Gathering has hellions, lava-dwelling insectoid worms. Maybe use stats for a remorhaz tweaked to fire?

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