Lightning Bolt

D&D 2024 spell: Lightning Bolt. Source: Player's Handbook (2024). level 3, school Evocation, casting time 1 action, range 100 feet (100-foot line), duration...

A stroke of lightning forming a 100-foot-long, 5-foot-wide Line [Area of Effect] blasts out from you in a direction you choose. Each creature in the Line [Area of Effect] makes a Dexterity saving throw, taking 8d6 Lightning damage on a failed save or half as much damage on a successful one.

At Higher Levels

Using a Higher-Level Spell Slot The damage increases by 8d6 for each spell slot level above 3.

Source: Player's Handbook (2024), p. 292 - Licenses and attribution