Volthys

A bolt of electricity arcs toward a target within range. The target must make a Dexterity saving throw. On a failed save, they take 3d6 lightning damage. If the target is wearing metal armor, they have disadvantage on the saving throw. On a successful save, they take half damage.

At Higher Levels:
When cast using a spell slot of 2nd level or higher, the damage increases by 1d6 per slot level above 1st.