Cobbleknacker's Crater

You create a 10-foot-by-10-foot extra-dimensional hole with a depth of 20 feet.

Any creature standing in the area where you first conjured the pit must make a Dexterity saving throw to jump to safety in the nearest open space. In addition, the edges of the pit are sloped, and any creature ending its turn on a square adjacent to the pit must make a Dexterity Saving Throw to avoid falling into the pit.

Creatures who fall into the pit take 2d6 bludgeoning damage and are knocked prone. The pit’s coarse stone walls have little to no hand holds, and a creature must make an Athletics check equal to your spell DC to escape. When the duration of the spell ends, creatures within the hole rise up with the bottom of the pit until they are standing on the surface over the course of a single round.

You must create the pit on a horizontal surface of sufficient size. Since it extends into another dimension, the pit has no weight and does not otherwise displace the original underlying material. You can create the pit in the deck of a ship as easily as in a dungeon floor or the ground of a forest.

 At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the width and depth of the pit increases by 10 feet for each spell slot about 2nd.