Elemental Plane of Fire replaced by Brown Mold

[Particle_Man]

I was trying to think out the consequences of this on the prime material plane for a setting. Thoughts?

[RifleAvenger]

If we're going by the assumption of a four core elements system, such that many things are made out of multiple elements, or all of them? If Fire is associated with heat? Disastrously.

The fire component of any thing or creature becomes mold, or takes on traits associated with mold instead of fire. The stars go out. Temperature declines precipitously until it reaches the same ambient temperature as the void, held in temporarily only by gravity, mantle convection and radioactive decay, and other physical laws. Or heat magically vanishes altogether as fire ceases to be.

The world would either quickly to immediately becomes a frozen, near lightless, moldy existence, or would be rapidly replaced by a new, alien material plane where thermodynamics is replaced by a near omnipresent living organism that varies in density (and if heat is being replaced by Brown Mold, I'm not sure how Brown Mold even feeds anymore!).

If you just replace actual fire, and not heat or other materials, with mold? It's still awful, and I still think it'd kill stars if the mold can withstand the heat of nuclear fusion (think how the mold would exponentially grow, being both created by the energy release of fusion "igniting" the hydrogen of the star, and rapidly expanding in the heat generated). If we ignore stellar implications, you still have a world where you can't cook anything, can't make a fire to get warm or provide light at night.

[AmeVulpes]

Think of all of the poor commoners with their pet Fire Elementals that live in their fireplace. In for a cold winter, certainly.

On a more serious note, I'd say RifleAvenger has it, unless the universe has some other heat source. Perhaps Evocation would still work? Evokers finally have their day.

EDIT: What happens if you destroy the mold? I'm sure an epic-level caster could come up with something plane-wide given the help of enough casters and spell slot sacrifice. Does the EPoF just reboot, or is it now a cold void of dead mold?

[daremetoidareyo]

Clerics with fire domain have it switched to the brown mold domain? Fire gods offer the plant domain?

Adventurers are breached to transport swaths of cold elemental cows that they convince iborighu to create in exchange for the power of some fire aligned God and have to deal with the "mold cowboys" clerics of the mold diety attempting transcenance into the pantheon by maintaining the new elemental plane of mold?

[RifleAvenger]

EDIT: What happens if you destroy the mold? I'm sure an epic-level caster could come up with something plane-wide given the help of enough casters and spell slot sacrifice. Does the EPoF just reboot, or is it now a cold void of dead mold?Depends on if the cause of the issue was Brown Mold being introduced to the EPoF, or something more metaphysical. In the former case, the fire probably comes back on if you're destroying the Mold in the EPoF; doing it on the material plane is useless, if you even survive the metaphysical warping as part of your body becomes mold and your internal temperature ceases to be or constantly grows the mold further. In the latter, get that epic spell to just reintroduce the Plane of Fire before it's too late.

My literal "it'd end the world" spheel before came from the experience of running an archmage chronicle in Mage the Awakening, and needing to invent an ex-scientist NPC archmage to tell off the party from trying some poorly thought out imperial spells. Ex. "I'll make a spell to make the recipient totally immune to electricity." "Yeah, sure, turn them into the ultimate resistor, stopping their heartbeat and nerve signals at best, and creating some utterly bizarre abomination of reality at worst because the EM force might as well not exist in their body." The only way to make huge universal changes like this to a setting is to cut off the implications at the point it ceases to be fun, or to just not do them.

[AmeVulpes]

Depends on if the cause of the issue was Brown Mold being introduced to the EPoF, or something more metaphysical. In the former case, the fire probably comes back on if you're destroying the Mold in the EPoF; doing it on the material plane is useless, if you even survive the metaphysical warping as part of your body becomes mold and your internal temperature ceases to be or constantly grows the mold further. In the latter, get that epic spell to just reintroduce the Plane of Fire before it's too plate.

I was going more with your "only fire" interpretation, rather than heat itself. Still a major problem for sure. Also, doesn't Brown Mold explicitly require fire rather than just heat in order to grow? I'm looking at the PDFSRD, so maybe it's different in different systems.

This whole thread has me very curious, how does this not naturally happen? Elemental vortexes open up all over the place, iirc. Given enough time, interaction with brown mold should be inevitable, I would think. How does OP's scenario not just, you know, happen on its own?

[InvisibleBison]

This whole thread has me very curious, how does this not naturally happen? Elemental vortexes open up all over the place, iirc. Given enough time, interaction with brown mold should be inevitable, I would think. How does OP's scenario not just, you know, happen on its own?

Unless I'm misremembering, the Elemental Plane of Fire is infinite in size. Thus, regardless of how much brown mold gets into the plane, there's still an infinite amount uninfected by mold.

[AmeVulpes]

Unless I'm misremembering, the Elemental Plane of Fire is infinite in size. Thus, regardless of how much brown mold gets into the plane, there's still an infinite amount uninfected by mold.

That is correct. Page 74, Manual of the Planes.

Still, I feel like it would be a local (to the EPoF) disaster. The 'infection' doubles in size every round it's exposed to fire. While never really infinite, that gets big quickly.

As an aside, I suppose this settles that OP's scenario, as written, can only happen for metaphysical reasons, rather than basic introduction of the mold.

Back to the matter at hand, it very much hinges on whether the DM decides that the EPoF is linked only to fire elementals, only to actual fire (for that matter, maybe even only nonmagical fire), or all heat in the universe.

[Zaq]

Regarding fixing the problem or addressing why it hasn't happened already: cold-damage attacks don't work especially well on the EPoF, but surely it's still possible to do something that'll spit out a single point of cold damage, right? Because a single point of cold damage destroys brown mold. It doesn't say that the cold damage only destroys a 5-ft patch, either. I think it destroys the entire thing, so even an arbitrarily large specimen of it that's been multiplying for a long time should still be destroyed by applying cold damage to any part of it. Brown mold is weird by RAW.

And, as stated, there's always more fire on the EPoF: it's infinite. Now, I don't know enough math to discuss how "big" an infinity the brown mold would be (is it infinite at all or just really big?), but still, you can't make the EPoF run out of fire. At least not without deity-level plot intervention.

If you want to assume that this moldpocalypse already happened and that it can't be easily fixed? As others have addressed, it depends on what role the elemental planes play in your game. Does all fire come from the EPoF? If not, that's a lesser impact than if you have to get the EPoF involved to light a nonmagical torch using flint and steel. It might just affect mages (specifically mages who dabble in planar stuff) and not be something that the average commoner notices, or it might make your Prime Material into an uninhabitable wasteland. Depends on your basic assumptions, I guess.

[ericgrau]

I think the base assumption that brown mold continues to redouble in size is false.

Assuming brown mold does continue to grow, though, even with an infinite plane of fire the fire that you pull from the plane of fire may still all be brown mold. IIRC the more tolerable areas in the plane of fire like the City of Brass are the ones closer to the material plane. All of those may be taken over by brown mold, while the super hot fire deeper in the plane of fire may be all that's left.

So [fire] spells, fire and possibly heat in general on the material plane may indeed succumb to moldpocalypse.

Or if you assume the material plane is already formed from the plane of fire (and other 3 elements) and needs no further input from it in the immediate future, only spells may be affected. But places where the plane of fire touch the material plane may leak in mold instead of fire, and gradually have consequences that way. Dealing with it could be a fun campaign. First everyone notices [fire] spells sometimes create brown mold. Within several days most then all [fire] spells do. Everyone begins to speculate that either magic or the plane of fire is wonky, but everyone is too scared to investigate. Soon their questions are answered without a plane shift though, as word spreads that mold is coming out of gates to the plane of fire. Residents of the plane of fire capable of travel are plane shifting to other planes. Mostly to elemental and outer planes, but some to the material plane.

You might want to come up with an explanation why this hasn't happened 1,000 times before and why someone couldn't easily do it again. Perhaps this is special brown mold that continues to feed rapidly, unlike the regular stuff that swells up and then takes a while longer to spread. Maybe an artifact did it, and some baddy got that artifact because his end plan is XYZ. Or whatever you make up. That leads to how the PCs solve the problem.

[Afgncaap5]

You might want to come up with an explanation why this hasn't happened 1,000 times before and why someone couldn't easily do it again. Perhaps this is special brown mold that continues to feed rapidly, unlike the regular stuff that swells up and then takes a while longer to spread. Maybe an artifact did it, and some baddy got that artifact because his end plan is XYZ. Or whatever you make up. That leads to how the PCs solve the problem.

I think the real question on Brown Mold's expansion is how quickly it creates a balance between itself and the environment. As written in the DMG, it 1) needs fire within five feet of it to double in size, and 2) always makes it cold for up to thirty feet away from itself (and the body heat of living creatures isn't sufficient to make it double.) It's possible that when it doubles there's an extinguishing effect as the heat is drained away, and that the new thirty-foot radius of coldness is now a safe zone. Having said that and riffing a little off your suggestions of artifacts and alternate strains of it, I've got three "why hasn't this happened" in my mind...


1) As with all things in the DMG, RAW is meant to be taken with a grain of salt and the mechanics presented tend to feature a "first contact" or "what's needed for a standard party" scenario (the DMG even goes so far as to point out that these are "normally" the rules for brown mold, allowing DMs to extrapolate for unusual scenarios like this). Any DM who chooses to adhere to RAW in its entirety without speculation, however, may find this dissatisfying and can choose to blast this solution away with their Commoner Railguns Aplenty™. Having said that, it's not unreasonable to assume that there's an upper limit to the growth of any given "patch" of Brown Mold or, at least, a point of stabilization where the capacity of a patch of mold to drain heat is limited both by its distance from a heat source and the speed of growth in such a way that the mold itself winds up creating "cold pockets" within the Elemental Plane of Fire. Just imagine, like, asteroids of brown mold the size of skyscrapers that are surrounded by atmospheres of coldness (at least thirty feet deep, but potentially more); any fire that gets into the pocket is extinguished before it can get close enough to the mold at the core. Doing this has the potential to create some counterintuitive but otherwise fascinating dungeons, such as, say, a flying castle in the Elemental Plane of Fire that's super cold, covered with mold, and turns out to be a temple to Zuggtmoy, filled with demons and fiendish plant/fungus creatures. Its orbit could take it perilously close to the City of Brass, and I'm sure the fire-based creatures would rather have some humanoids go and deal with this fire-extinguishing threat rather than dealing with it themselves. Alternatively...

2) The inhabitants of the Elemental Plane of Fire themselves. Keep in mind that this is an entire reality with its own laws, customs, traditions, histories, magics, sciences, villains, and heroes. Aimarisder the Azer may have wielded a Cobalt Shield of his own crafting that could protect the bearer from giving off any heat signature so that they could get close enough to a patch of brown mold to exterminate it. Ssardon Zey the Salamander might have bargained with a balor prince to gain a single torch of Hellfire capable of burning the essence of the mold away faster than it can grow, being a torch that burns not with fire but with the concept of hunger itself. And what of the mighty Fire Giant sages and Ifrit Kings, wielding magics that humans only speak of in legend? They know where the Fire That Has No Heat burns brightest, which forges make the most impenetrable walls, what magics can bring about worlds just like their own but where the mold never existed within it. Surely, brown mold is a danger, but not one that they haven't already thwarted thousands of times before! Players visiting the plane might see such a patch of expanding mold on the way and be tasked with searching a nearby legendary fortress for whatever ancient tool was used to combat it in previous scenarios, providing an interesting adventure where the dungeon isn't necessarily hostile, but it's large and confusing and the players have to work against the clock, and ultimately I can see this being a memorable evening of playtime! Or, let's assume that the DM prefers a bleak outlook where giants and sorcerer kings with the powers of genies can't solve problems that players with characters typically can. In that case, the Elemental Plane of Fire may still be saved by...

3) Math! The size of the plane is Infinite. Even if we assume a frankly laughable and mimesis-sundering rate of expansion equal to the speed of light and a capacity for growth without an upper limit, infinity is still infinity and Brown Mold's rate of growth is merely what my math professors would refer to as "countably infinite". There may already be massive galaxy-spanning, ever-doubling patches of the Elemental Plane of Fire undergoing this travesty already, but ya know what? They're way over there, infinitely far away; even if it was only a tenth of that distance it would still be impossible to reach me through conventional growth rates. The Brown Mold won't ever consume the entire plane of fire because there's always more plane of fire to consume. I'm sure there's all sorts of magical implications and ways that this mold will still be a travesty for the inhabitants of the prime material plane but, frankly, we've got to use our imaginations to determine what those travesties are (and if we're resorting to that kind of thing, then the solutions in option #1 should've been valid well before now). If you go with this route, the interesting adventure might be one of exploration: a powerful salamander sorcerer or fairy pyromancer might offer the players a chance to go to one of these brown-mold infested patches of the plane via teleportation; get certain plot item for the quest giver, and keep whatever other treasures you find. I'd suggest any number of sci-fi or action movie plots for this kind of thing. You know the ones: there's an abandoned facility, but something *bad* went down there, but we think your skills are perfect for getting something we need back out, but wait that person working for our employer is backstabbing us?! Aw, geeze, now we've got Magmin-Mold Zombies swarming us and they're taking the tele-chopper away, dangit, what now...