This spell causes a ball of oil to appear over the target and burst covering the intended target's in a covering of fine oil [no save]. When fire is added to the iol it burns for 4D10 points of damage plus what ever set it off [So if a fire ball is used to inight the oil the damage is the D6 plus 4D10 points of damage.]. This is wear the save comes in for half damage.
The material component is a small vial of fine oil [value1500 gp]