Can two wizards combine demi planes?

[WitchyTangles]

I thought that there were rules for combined casting some where, but I can't find it. Two wizards pc's want to merge their demi planes and I want to know if there were rules for this.

[Thomas Long 175]

I don't really know the answer but I will state this sounds like the start of a bad sci fi apocalypse movie.

[seebs]

So far as I can tell, they can't, the demiplane is always yours personally.

[WitchyTangles]

Quote:

I don't really know the answer but I will state this sounds like the start of a bad sci fi apocalypse movie.

LOL!!It does! It sounds terribly Doctor Who or something much weirder that I don't even want to contemplate.

[LazarX]

GM call.

[Owen K. C. Stephens]

You can use multiple castings of create demiplane spells to expand the size of your demiplane, and with greater create demiplane you can put in a portal to link to another demiplane, but neither of those is quite what you are looking for.

Of course if you can create a demiplane you're at the level where such things as limited wish become available, and I'd think linking two "friendly" demiplanes would fall within that spell's power.

[WitchyTangles]

Thank you! =}

[Lincoln Hills]

You might see if anything in Distant Realms deals with demiplane connection. I know that in 3rd Edition's Psionic Handbook, demiplane connection was at the discretion of the creator (although such doors might have been 'out only' if the plane on the other end wasn't built for such connections... hm, good trap idea).

Mind you, I'm talking about portals that connect the two, not merging them into a single space. Although once you have forty or fifty connections, you have a non-Euclidean demiplane maze that... hm, good trap idea.

[seebs]

I'm not even sure I'd consider linking two demiplanes to be within scope for a wish. It creates fairly serious technical questions. What happens if the demiplanes have incompatible plane-wide traits like magic types? Or time scale? Who can then eject people from the resulting plane, or does it depend on where on the plane you are?

Note, demiplanes with unusual properties are full of weirdness. Can you eject people from a dead-magic demiplane? The rules say you're trapped if there's not a permanent gate, but I can't see how you're trapped if you can be ejected. But maybe the dead-magic thing trumps the usual booting people thing. In which case, hope you didn't use permanency on it.

As a side note: create demiplane is conjuration (creation). So far as I can tell, rules-as-written, a caster who can cast shades can create an 80% real shadow demiplane as a standard action. They can also cast an 80% real trap the soul without a material component, and I have no idea what's supposed to happen with that.

[LazarX]

seebs wrote:

I'm not even sure I'd consider linking two demiplanes to be within scope for a wish. It creates fairly serious technical questions. What happens if the demiplanes have incompatible plane-wide traits like magic types? Or time scale? Who can then eject people from the resulting plane, or does it depend on where on the plane you are?

The easiest form of link to mange would be that of a permanent gate between the two planes. In that form the questions are easy to answer.

1. Planar traits don't cross. traits on each plane remain the same.

2. Both planes traits are managed by their relation to the Prime not to each other. as the environments are separate, the fact that one is running faster and slower isn't a problem.

3. the creator of the specific plane.

[Avatar-1]

seebs wrote:

I'm not even sure I'd consider linking two demiplanes to be within scope for a wish. It creates fairly serious technical questions. What happens if the demiplanes have incompatible plane-wide traits like magic types? Or time scale? Who can then eject people from the resulting plane, or does it depend on where on the plane you are?

Sounds exactly like the scope of Wish.

[Ciaran Barnes]

This might be in the realm of a home brewed higher level spell, or a custom magic item.

[Tomos]

Sounds like a great story hook.

Those Wizards have just created their own quest. Figuring out how to merge demiplanes would probably be a very valuable secret.
It could require: extensive research in ancient (well-guarded) libraries, special and rare spell components/foci, a dangerous artifact, new spells, something evil working against them, other wizards trying to steal their research.

Exciting!

[Lifat]

By RAW there is no way of doing this. If you want to allow them this anyway the only option is homebrew/houserules.
You have a few options.

1. Allow limited wish or wish to work with combining the demiplanes.
2. Make them go on a big quest for this artifact that lets them
3. Simply allow them no other hassle necessary.
4. Create a new spell for it.
5. Think up something yourself.

No matter the way you do it, you should be careful and tell the players that if it does something unintentionally powerful then you might slap them with a new houserule.

Either way you do it, I would not allow it for demiplanes with incompatible traits.

I would allow both owners to boot people from their plane. Not just the half they created but the entire thing.

[Narquelion]

RAW, each PC can make a 20 feet wide gate connecting the two demiplanes; possibly more, if you rule that they can add more than one gate to each plane by casting greater create demiplane multiple times.

[Lifat]

Narquelion wrote:

RAW, each PC can make a 20 feet wide gate connecting the two demiplanes; possibly more, if you rule that they can add more than one gate to each plane by casting greater create demiplane multiple times.

I doubt OP was talking about Gates, but you are right that it would be the closest you could get by RAW.

[Narquelion]

Lifat wrote:

I doubt OP was talking about Gates, but you are right that it would be the closest you could get by RAW.

Just in case the OP decide to propose a quick and dirty solution to her players. Two doors as large as living rooms would make the demiplanes connected enough for most practical purposes.

Or she could cook up a new humanoid race and start statting that Investigator20/ Trickster10 with the deluxe version of Baba Yaga's Hut, I suppose...

[maouse]

So what happens when another mage casts demi-plane on your demi-plane? they get a window out from yours only, to theirs... could be an interesting "deeper demi-plane" idea.

[WitchyTangles]

I've read through some options and I think that it's going to come down to something along the lines of a limited wish/wish. But they're going to be sent on a research and ancient lore seeking quest and will require travel to some incredibly dangerous locations to get it at all. And then it'll only be possible if both demi-planes are made permanent, are compatible options-wise and are created in the same plane, ie astral planer. It makes sense this way and makes a character driven story more exciting than just a sure-why-not ruling.