You tear a hole in the tapestry that makes up the cosmos.  A planar rift that takes the form of a 30-ft. circle or square opens a portal to another plane of existence.  Any creatures in the rift when the spell is cast take 1d12 force damage and are dropped into it.  A creature that enters the rift passes through the Far Realm on its way to the destination plane.  The creature takes 6d10 psychic damage as the cosmic insanity and horror of the Far Realm is too great for its mind to bear.  It appears on another plane randomly determined by the DM, close to the rift opening but not in its space.  The creature must succeed on an Intelligence saving throw or become stunned until the end of its next turn.  

Creatures that are within 10 ft. of the rift when the spell is cast might be pushed in by the planar force.  If a creature is within 10 ft. of the rift, it must make a Dexterity saving throw or be affected by the spell as if it were inside the area of effect.    

The DM might instead teleport the creature a distance of at least 3 miles away on its current plane, rather than teleporting the creature to another plane of existence.

The rift remains in the area for 1 hour.  It can be removed by a dispel magic spell.  An antimagic field suppresses the rift, but does not dispel it.     

At Higher Levels.  When you cast this spell using an 8th-level spell slot or higher, the psychic damage increases by 2d10 for each spell slot level above 7th.  The area of the rift increases by 10 ft. for each spell slot level above 7th.