Electric Chute

You hurl a ball of electricity. Choose one or two creatures you can see within range. If you choose two, they must be within 5 feet of each other. A target must succeed on a Dexterity saving throw or take 1d4 lightning damage and be stunned until the start of his turn.

This spell’s damage increases  when you reach 5th level (1d6), 11th level (1d8), and 17th level (2d8).