Cage of Thorns

Choose a target creature within range that is touching the ground: a morass of spiked vines sprouts below the target.

The target must make a Dexterity saving throw. A creature takes 2d8 piercing damage and is restrained on a failed save, or takes half as much damage on a successful one. If the creature succeeded the saving throw, the targeted square becomes Difficult Terrain.

A creature that is restrained this way can end the effect on itself by succeeding a DC 13(if your spell save DC is higher than 13, use that value instead) Strength saving throw at the start of its turn. If it fails the saving throw, it also takes 1d4 piercing damage.

An adjacent creature may spend their action to give Advantage to the Strength saving throw of the restrained creature.

At Higher Levels. When you cast this spell using a spell slot of 3rd or higher level, the damage dealt when failing the Strength saving throw increases by 1d4 for each slot level above 2nd. Additionally, if you use a spell slot of 4th-level or higher, the targeted creature has Disadvantage on the Strength saving throw to break free.