A magical rune(s) appears around the caster and shoot a beam of magic at the target.
The target makes a Dex saving throw agents the attack, on failure roll equal to spell level. On success the beam misses and hits the tile behind making it rough terrain.

Each turn the runes fire up to two beams, each rune may target a different creature, object or tile.

The amount of runes that appear are equals to the half spell level and attacking the runes have no affect on the spell.