Arc

You draw an arc of lightning from the ground or a grounded object to your hand, then sweep it out towards a creature within range. Make a ranged spell attack. On a hit, the target takes 1d4 lightning damage. 

If you roll a 4 on one or more of the damage dice, the lightning leaps to another target that you can see within 30 feet of the original, and you can make another spell attack against that target immediately.  This leap will not occur more than once.

Even if you use a spellcasting focus to replace this spell's material component, you must use a free hand to perform the somatic component.  You do not have to be wielding your material focus for this purpose; you can draw the arc from a staff slung across your back or a crystal in your pocket.

This spell’s damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).

[Alternative version - simplified]

Deals 1d6 to 4d6 lightning damage with no secondary effect.