Labyrinth of the Devouring Loam

Description

You slap the scored clay tile to the ground and a 40-foot cube of earth churns into a living maze. Walls of packed loam and grinding stone, 10 feet high, heave up throughout the area, and at the start of each of your turns you can reshape them, causing the walls to rise, sink, or shift to new positions within the cube. The entire area is difficult terrain. When the maze first forms, and whenever a creature starts its turn within the cube, that creature must make a Strength saving throw. On a failed save it takes 2d10 bludgeoning damage as the walls grind together and is restrained by grasping earth until the start of its next turn; on a success it takes half as much damage and is not restrained. A restrained creature can repeat the save at the end of its turn, freeing itself on a success. A creature that leaves the cube ends these effects on itself.