A grease spell covers a solid surface with a layer of slippery
grease. Any creature entering the area or caught in it when the
spell is cast must make a successful Reflex save or slip, skid,
and fall. Those that successfully save can move at half speed
across the surface. However, those that remain in the area must
each make a new saving throw every round to avoid falling and to
be able to move. The DM should adjust saving throws by
circumstance. For example, a creature charging down an incline
that is suddenly greased has little chance to avoid the effect,
but its ability to exit the affected area is almost assured
(whether it wants to or not).
The spell can also be used to create a greasy coating on an
itema rope, ladder rungs, or a weapon handle, for instance.
Material objects not in use are always affected by this spell,
while objects wielded or employed by creatures receive a Reflex
saving throw to avoid the effect. If the initial saving throw
fails, the creature immediately drops the item. A saving throw
must be made each round the creature attempts to pick up or use
the greased item.