A Banishment, also known as an Imprisonment, sends a fellow to another Plane. How they get back to the regular Plane is up to them.

Most Banishing occurs in combat. The common destination Planes for a Banishment are the Inferno, Kokytos, and the Void.

• A fellow may be banished to the Inferno by Infernal Prison, a 31 Blood spell of the 8th level.
• A fellow may be banished to Kokytos by Claws of Kokytos, a 31 Blood spell of the same caliber as Infernal Prison.
• A fellow may accidentally banish themselves to the Void with the Returning spell, a 2 Thaumaturgy of the 2nd level, though the spell is meant to teleport the caster to their nation's capitol. Likewise, the Vortex of Returning spell (4, Thaumaturgy 7) has a small chance to banish any of the caster's allies instead of teleporting them.

There are also Artifacts that do the job, on hit, though sometimes that's easier said than done.

Technically speaking, Banishments are forced teleports to specific provinces that have no province connections, internally called "Planeshifts". With Dominions 6's addition of Nexus to the Void, the definition has gotten a bit fuzzier; it isn't yet clear if being Banished to the Void can send you there, however. Internally, the Inferno is considered Province -12, and Kokytos is considered Province -13.