Loop

You cause an area to be instilled with a powerful spatial illusion that affects creatures' perception on their locomotion.

Whenever a creature enters the area, or begins its turn in the area, it must succeed on an INT saving throw or else be affected by the illusion. Upon a success, it is immune to the effects of this spell for 1 minute. You may designate specific creatures or groups of creatures (such as designating a particular race or a group of creatures following a particular god) to be unaffected by this spell.

You choose the nature of the illusion, provided that it affects a creature's perceived locomotion. For example, you could cause a particular object within the area to be unreachable; creatures perceive it to never get any closer. Another example includes making two areas to be connected when approached a certain way; creatures perceive to loop back to a particular area (or perhaps not noticing it at all if the two areas are very similar). The DM has the final say as to whether the effect is acceptable.

In reality, whenever a creature's perception is affected by this illusion, it is simply walking on the spot, or walking in a short loop of some kind. While affected in such a way, if a creature decides to turn back, they return to walking and perceiving the area around them normally.

If a creature suspects that something is amiss, it can attempt an INT (Investigation) check against your spell save DC. On a successful check, the illusion for them is dispelled, and they become immune to the effects of this spell for 1 minute. On a failed check, they automatically fail all further checks for 1 hour.

Creatures with an INT score of 4 or lower, creatures with Truesight, and creatures that don't rely on sight (such as those with Blindsight) are unaffected by this spell.

At Higher Levels: Increase the size of the Cube by 50m for each spell level increase. When casting this spell at 8th level or higher, this spell lasts until dispelled.