Acid Slip

A ten foot radius circle of slippery acid is created on the ground as the spell is cast. Each creature within the spells area of effect must make a Dexterity saving throw or slip, taking 3d6 poison damage upon a fall. A pass will take half damage and remain upright. The circle is now difficult terrain. 

Each time a creature begins its turn in the area, they must make the saving throw and take the full/half damage.