The Resilient Decanter Nuke -- How To Destroy a Plane With Five Things

[LastCenturion]

I found an exploit on this Reddit thread (https://www.reddit.com/r/DnD/comments/2n8h4l/35_so_my_players_want_to_make_a_nuke/) yesterday, proposing using Resilient Sphere in conjunction with a Decanter of Endless Water to destroy a city. The problem with this is that the decanter will be destroyed early on in the fusion, ceasing the buildup. This can be overcome by constructing the Decanter with riverine (for those who don't know, it's an unbreakable material from Stormwrack that uses shapeable Wall-of-Force effects). There you go; it works. You've destroyed a city.

https://what-if.xkcd.com/imgs/a/13/laser_pointer_more_power.png

How about an Extended Resilient Sphere? It's a little bit harder to pull off, but it increases the power of your bomb by a lot. I don't really know how much, because I don't understand high-pressure water very well, but it's fair to assume that you're now leveling an entire metropolitan area. Perhaps your party will need a better way of getting you out, but forty minutes is a while.

https://what-if.xkcd.com/imgs/a/13/laser_pointer_more_power.png

Err... Okay. Let's get a custom magic item that gives us a permanent Resilient Sphere (by the rules on d20srd.org, it's 112 thousand gold pieces even) and fill that. We can use a Dispel Magic effect and contingent Teleport to get out fast enough. We can probably level a continent or two by letting the pressure build for a few days.

https://what-if.xkcd.com/imgs/a/13/laser_pointer_more_power.png

I did promise plane destruction in the thread title, so let's try that. Building up that much pressure would take a really long time -- like, hundreds of millions of years -- so let's see if we can skip that. We could use more and more Decanters, but it would take hundreds of thousands to reduce the time all that much. Let's go a different direction: extraplanar. A scroll of Genesis would cost 28 825 gp using the same rules as before. Give it a week and we have a demiplane large enough for our sphere. A week in the material plane, that is. We want to go fast, so let's have one round in the material plane be about one billion rounds in our demiplane. I can't find a rule that says there's a limit to how fast time moves in a demiplane, so I guess it works. It still takes four months or so to charge the sphere, but that's much better than millions of years. But now we're only destroying our demiplane. We want to destroy the Prime Material Plane, so let's see. Using the Planar Travel version of Gate seems to work for energy, so let's get a scroll of that. 3825 gp, by our table from earlier. Finally, we need to release the energy. It costs only 375 gp for a scroll of Dispel Magic, so we'll go with that.

So we have an item of Resilient Sphere, a Decanter of Endless Water (Riverine edition, weighs two pounds; adds 4 thousand gold to the cost), a scroll of Genesis, a scroll of Gate, and a scroll of Dispel Magic.

Cost:
- Resilient Sphere item: 112 000 gp
- Riverine Decanter of H2O: 6 000 gp
- Scroll of Genesis: 28 825 gp
- Scroll of Gate: 3 825 gp
- Scroll of Dispel Magic: 375 gp

Total: one hundred and fifty one thousand and twenty five gold pieces (151 025 gp). Just barely outside the entire WBL of a fourteenth level character.

What's that? You want to survive? Fine, just get a Contingencied Plane Shift to take you away as soon as you cast a Dispel Magic scroll. 3375 gp for the both, including the fact that the Contingency scroll needs a minimum caster level of 15 in order to work for Plane Shift.

Total for doing the whole thing AND surviving: 154 400 gp. Still easily obtainable by a level 15 character, even with minor efforts to equip oneself.

This has been:
How to Destroy A Plane With Five Magic Items (Or Survive Destroying A Plane With Six)

[ben-zayb]

I'm curious how you arrived with the numbers on how much pressure it takes to destroy the (not the plane, no) materials/objects of a plane whose dimensions wasn't even specified, and how much pressure builds up for that much length of time

[Eldariel]

I highly doubt what essentially amounts to a nuclear explosion will do anything to the fabric of a plane. Its contents, sure, an explosion of vast intensity could do some real damage, but the plane itself would likely persist. And of course, many planes are infinite, making this method infeasible unless one managed to produce a self-replicating reaction.

Ultimately, I'm a bit bothered by the fact that this idea is essentially resorting to two custom magic items (who says a functional Decanter could even be made of Riverine? Or that there are items of permanent Resilient Sphere?), but the Force container part is easily solved by e.g. making a cube out of Permanencied Walls of Force. Still, at the point where we're making custom items we might as well just create a magical antimatter bomb to much the same effect, and call it a day.

[Necroticplague]

I understand that, by real life logic, something like this would do a lot of damage. But do you have any source to back up that this would ever do anything in-game as a result of all this pressure being released?

Also, this requires assuming that the Decanters act like volumetric pumps. If they acted like pressure pumps, than this simply isn't physically possible, and it isn't specified either way.

Also, most planes are infinitely big. While you could use this to create an arbitrarily large burst of water, you can't use it to make an infinitely big one. At any given moment in time, the burst would be a finite value, thus not capable of covering the entirely of the infinitely-big plane.

[LastCenturion]

I'm curious how you arrived with the numbers on how much pressure it takes to destroy the (not the plane, no) materials/objects of a plane whose dimensions wasn't even specified, and how much pressure builds up for that much length of time

I admit to having absolutely no idea how much pressure it would take to destroy the physical part of a plane, but I assumed if the water in the globe was compacted to the density of a neutron star (about 1017 kg/m3) then the expansion and fusion would be enough.


I understand that, by real life logic, something like this would do a lot of damage. But do you have any source to back up that this would ever do anything in-game as a result of all this pressure being released?

Also, this requires assuming that the Decanters act like volumetric pumps. If they acted like pressure pumps, than this simply isn't physically possible, and it isn't specified either way.

Also, most planes are infinitely big. While you could use this to create an arbitrarily large burst of water, you can't use it to make an infinitely big one. At any given moment in time, the burst would be a finite value, thus not capable of covering the entirely of the infinitely-big plane.

All fair points. This isn't really meant to be a completely serious method of planar destruction, but you must admit that it's a pretty cool idea.

And Decanters definitely act like volumetric pumps, assuming they even work as pumps. The water isn't pumped out of the decanter, it's created at the mouth, moving at a set pace.

[Necroticplague]

And Decanters definitely act like volumetric pumps, assuming they even work as pumps. The water isn't pumped out of the decanter, it's created at the mouth, moving at a set pace.

Where's it say the water's created? It says it pours out the water, not necessarily that it creates it. It's entirely possible it's simply transporting it from elsewhere (like the infinitely-big ball of water that exists in the form of the Plane of Water). In which case, you'd expect a strategy like this to only result in it rising to the pressure of it's source.

[Cirtona Pox]

I admit to having absolutely no idea how much pressure it would take to destroy the physical part of a plane, but I assumed if the water in the globe was compacted to the density of a neutron star (about 1017 kg/m3) then the expansion and fusion would be enough.

The math is off just a bit...

The water is created just inside the mouth of the container so increased pressure at the rim would cancel the flow.

The water is forced out at 30 gallons per round (5 gallons per second).
A 10 foot globe has a volume of just over 524 Imperial Gallons

So once the volume inside the globe reaches 2620 gallons (compressed to 524 gallons) the push back pressure will actually cancel out the decanters flow rate.

You can rules lawyer it all you want but even if you doubled the volume you would still only wind up with a loud pop and a couple flooded basements.

Still a nice mayhem approach though :)

[icefractal]

I'm not quite sure about this method, because it relies on "RL physics does apply" for one thing (having pressurized water do more than get things wet), but then relies on "it's magic, not physics" for another (having the decanter still produce water no matter the pressure against it).

However, if it does work, you don't need the Resilient Sphere. A demiplane itself is an enclosed volume, and the one that Genesis makes isn't very large. Just put the decanter inside, let it charge up, and then the act of opening a Gate will unleash the destruction.

[Tvtyrant]

This is a fairly old trick. There was a thread 4-5 years back where it was discussed how long it would take a permanent shaped wall of force into a cube with a riverine decanter of endless water to take on enough mass to become a black hole.