I want to cast a 5th level Banishment on two party members who are both native to the Astral Plane. Theoretically they will both fail their save (Silvery Barbs and a high save DC). We are currently on the 4th layer of the Nine hells and my Word of Recall spell failed as the DM ruled teleportation doesn't work there.
My DM is still mulling over how he wants to handle it, but I thought the question was intriguing enough to ask here. Note, I'm not asking where they go, as this has been answered already here. Do they both go to the same location or separate ones?
Best Answer
Obviously, the DM will have to decide
The spell says:
That's all it says. Usually it doesn't matter; after all, if you're just getting rid of a pesky planar interloper, who cares, right?
But in your case, it matters, a lot.
Absent any rules guidance, and I am unaware of any, the DM may want to let the narrative drive the answer.
Some things for the DM to consider:
Where would each target go if they alone were the target of the spell?
In some sense, the spell is sending you "home". Maybe a reasonable destination within the home plane, is near the target's "home", or something approximating that. For instance, you're from some town in some country on some continent in or near the narratively important portion of the material plane . . . then maybe that's where you get sent to.
So in your case, perhaps individually the astral dwellers would get sent "home" to the astral plane, and end up somewhere near whatever they consider home within the plane.
Maybe you get sent home
So, maybe, both subject to the same casting of the spell, they both get sent to their "homes", whatever that means, within the astral plane. Maybe they're from the same place, or maybe they aren't.
Maybe affinity matters
They are both subject to the same casting of the spell, they are physically close to each other, they know each other, maybe they have other bonds.
So, maybe the DM rules they go to the same place on the astral plane, wherever that destination is, on the logic there are multiple factors binding them together, and so that causes them to go to the same place.
Maybe spellcaster intent matters
The spell doesn't give the caster any ability to specify location, but maybe the DM takes into account the caster's intent anyway. Magic's weird, right?
Maybe the desires of the targets matter
Okay, probably not, but again, magic's weird, right?
Having expressed a desire to go to the same location, the DM could choose to narrate it that as the magic is sucking you into the interplanar vortex, you grab each other, and appear in the same location in the astral plane.
Maybe the needs of the story matters
What services the story better? Same or different destinations?
One DM's opinion
I would consider the needs of the story first, then the desires of the caster. If that wasn't sufficient to drive an answer, I'd consider the other factors I've mentioned.
As a hypothetical, assuming the caster wants the two to go to the same spot, and it served the story, then that's what I would do.
I would likely not tell the caster that they know for sure they can send them to the same place. Although . . . maybe this particular caster knows a lot about banishment. Or maybe there's an arcana check involved.
It sounds like you're (smartly) discussing with the DM beforehand. In such a situation, I might tell the caster, you think you can influence their destination, but you're not sure; what do you, the caster, want to happen?
Or, when the caster cast the spell, I might ask, so, just out of curiosity, where do you want them to go?
Some players would immediately start looking for a loophole to exploit. They might ask, "will it always work that way?", and busily start imagining, 1. Cast banishment, 2. ????, 3. Profit. Use it as a way to infiltrate the Holiest of the Holies, or the National Treasury, or whatever.
If asked, I would shrug and say, "Hmmm, you're pretty sure that you did that, that you made them go to the same place, but you're not sure. You're welcome to research it. You think maybe you could do it again, but again, you're not sure. You're certainly welcome to try."