The caster encases a target within range's feet in a perfectly smooth forcefield only permissive to light, gases and liquids. For the duration, the target has disadvantage on all Dexterity saving throws, and upon moving, must make a Dexterity saving throw while turning, or continue to slide in a straight line for a distance equal to a third of their total movement made this turn. In addition, the target has advantage on saving throws made against effects targeting the feet. Creatures using the spider climb effect must succeed on a dexterity saving throw while suffering from this effect at the start of each turn or fall off of ceilings/walls. Targets with a climb speed have it reduced to half. 

At higher levels.

When cast with a third level slot or higher, the spell no longer requires concentration.