Our party was just forcibly transported to the City of Brass on the Plane of Fire. Our Cleric (who has the spell) immediately told our Warlock (who can have the spell) that between the two of them, they could banish the entire party including themselves back to the Prime Material Plane. And they could do it right away if needed, as they had the spell slots needed for it.
The DM paused, not realizing the entire plot for this adventure could be avoided in moments, gulped.
We decided for now to take on the adventure anyway. But it was amusing, and I had never considered Banishment as a transportation spell for our party.
Fun take on it although the "right away" part is somewhat foiled by the "If the spell ends before 1 minute has passed, the target reappears in the space it left or in the nearest unoccupied space if that space is occupied" clause in the spell description. Being a Concentration spell, it ends when cast again before a minute has passed. It would not be so effective in a situation where the party is in imminent danger. Nevertheless, the spell creates a nice escape hatch if the PCs are boxed in somewhere and have a few minutes to spare, depending on the size of the party.
Yeah by "right away" I meant "within the hour". We were not in imminent danger in the moment, and had just been given our quest which would take days. We thought of just bailing. And as the spell is not expressly labelled as a party-planar-transportation spell, I don't think he realized we had a means to return available.
It seems to me that someone will get left behind though, as who banishes the banisher?
You can cast it on yourself. "One creature that you can see within range" has been ruled as including yourself.
You would need a mirror then as one normally cannot see oneself.
So in this Sage Advice (https://www.sageadvice.eu/2016/12/01/can-you-cast-banishment-on-yourself/), it looks like you can cast it on yourself -- But. You also have to fail the save and you have no control as to where you end up. So it is a bit of a desperation move.
Wow, has SA ruled that you cannot voluntarily fail a saving throw?
Apparently it is the language in the spell itself "The target must succeed on a Charisma saving throw or be banished." he is basing his ruling on and not a general case.