Chromatic Line

You place a 20 foot line on the ground that glows in a chromatic rainbow within range of you. Each time a creature steps over the line you choose acid, cold, fire, lightning, poison, or thunder for the type of orb you create. The target must make a Dex saving throw against your spell save DC. If the attack hits, the creature takes 2d8 damage of the type you chose and has their movement halved for the duration of the spell.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.