The caster causes a mass of tentacles to spring from the ground in a 20 foot sphere, centered on a target. Each target of the caster's choosing in that radius must make a Dexterity saving throw. Targets that fail the saving throw become Paralyzed. At the start of their turns, targets takes 3d6 Force damage. The spell ends when the saving throw is a success.

When you cast this spell using a spell slot of 4th level or higher, the damage per turn increases by 1d6 for each slot level above 3rd.