Last session, the PCs summoned some elementals in summoning circles - basically, a Pentagram spell. They left the elementals there.
Elementals can leave after an hour . . . but what if they are stuck in a Pentagram?
The PCs just don't know.
It's a big question, actually. Can a Pentagram basically contain a summoned creature forever? Or do they just get to leave after a time?
It's an unresolved question. So is the idea of casting Banish at a creature in a Pentagram. How do they interact?
I have answers for some of these, but the PCs do not. I'm curious if others have answered these questions in their own way in their games.