Black Ice

You cause a patch of nearly transparent ice to form on ground that you can see within range. Until the spell ends, the magic ice fills a 5-foot square. Any creature on the ice’s space when you cast the spell must succeed on a Dexterity saving throw or take 1d6 cold damage. If the creature is Medium or smaller, it also falls prone on a failed save.

A creature must also make the saving throw when it moves onto the ice’s space for the first time on a turn or ends its turn atop it.

This spell’s damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).