Acid Pool

You conjure a bubbling pool of corrosive acid on the ground in a 10-foot square centered on a point you can see within range. For the duration, any creature that starts its turn in the pool must make a Constitution saving throw. On a failed save, a creature takes 4d4 acid damage and has its speed reduced by 15 feet. A creature takes half as much damage on a successful save, and doesn’t have its speed reduced.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 2d4 for each slot level above 3rd.