Chain Dragon Lightning

This spell creates an electrical discharge that begins as a single stroke commencing from your fingertips then strikes one object or creature initially, then arcs to other targets.

The bolt deals 11d8 to the primary target. After it strikes, lightning can arc to a number of secondary targets equal to twice Level Cast. The secondary bolts each strike one target and deal half as much damage as the primary one did (rounded down).

Each target can attempt a Dexterity for half damage. You choose secondary targets as you like, but they must all be within 30 feet of the primary target, and no target can be struck more than once. You can choose to affect fewer secondary targets than the maximum.