Arcane Spear

The castor launches an arrow of arcane energy in a 5ft wide 50ft long line. The first target in the line takes the full front of the damage and the arrow will continue to go through them. The first target of the spell must succeed on a Dexterity Saving throw, taking 6d8 force damage on a failure or half as much damage on a success. Any creature that is standing behind the first target in this line must also attempt this saving throw as well  however if they fail they will take half that damage and take no damage if they succeed.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd