Wall of Lightning

You create a wall of crackling, blue-white energy on a solid or liquid surface within range. You can make the wall up to 60 feet long, 20 feet high, and 8 feet thick, or a ringed wall up to 20 feet in diameter, 20 feet high, and 8 feet thick. The wall lightly obscures creatures and objects behind it and lasts for the duration. When the wall appears, each creature within its area must make a Constitution saving throw. On a failed save, the creature takes 3d6 lightning damage, or half as much damage on a successful save. A creature predominantly wearing or made of a conductive material such as metal or water takes a -2 penalty to the saving throw.

A creature that enters the wall for the first time on its turn or ends its turn there must make a Constitution saving throw. On a failed save, the creature takes 2d4 lightning damage and is stunned until the end of its next turn. On a successful save, the creature takes half as much damage and isn't stunned. A creature predominantly wearing or made of a conductive material such as metal or water takes a -2 penalty to the saving throw.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the initial damage increases by 1d6, and the sustained damage increases by 1d4, for each slot level above 3rd.