Grease

Standard Action | V, S, M | Close | 10 ft Square
1 Minute/level | Reflex negates | No
Covers a solid surface with a layer of slippery grease. Any creature in the area when the spell is cast must make a successful Reflex save or fall. A creature can walk within or through the area of grease at half speed with a DC 10 Acrobatics check. Failure means it can't move that round (Reflex save or fall), while failure by 5 or more means it falls (see the Acrobatics for details).