Witch Bolt
Level 1 Evocation
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (a twig from a tree that has been struck by lightning)
Duration: Concentration, up to 1 minute
Editor's Note
This spell's range has been increased from 30 feet to 60 feet, the auto-hit damage increases on upcasting, and the spell only ends when the target meets the conditions at the end of your turn.
A beam of crackling, blue energy lances out toward a creature within range, forming a sustained arc of lightning between you and the target. Make a ranged spell attack against that creature. On a hit, the target takes 1d12 lightning damage, and on each of your turns for the duration, you can use your action to deal 1d12 lightning damage to the target automatically. The spell ends if you use your action to do anything else. The spell also ends if the target is outside the spell's range or if it has total cover from you at the end of your turn.
At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, any damage dealt by the spell increases by 1d12 for each slot level above 1st.
Source: Player's Handbook, p. 289