Arced Lightning

You create a bolt of lightning that arcs toward a target of your choice that you can see within range. The target must make a Dexterity saving throw. The creature takes 9d6 lightning damage on a failed save, or half as much on a successful one.

Lightning arcs from the creature, and you are able to target up to 3 additional creatures (who may not be targeted twice by an arc) within 20 feet. Those creatures must make Dexterity saving throws. Each target takes 6d4 lightning damage on a failed save, or half as much on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage (both initial and arcs) increases by 1d6 and 1d4 respectively, and one additional arc leaps from the first target to another target, for each slot level above 3rd.