Any creature that takes damage from this spell must also succeed on a Reflex save to avoid injuries to its feet and legs. A failed save causes the creature’s speed to be reduced to half normal for 24 hours or until the injured creature receives a cure spell (which also restores lost hit points). Another character can remove the penalty by taking 10 minutes to dress the injuries and succeeding on a Heal check against the spell’s save DC.
A troll walks over the area of a spike stones spell, and takes several d8's of damage, which he quickly heals via regeneration. He did not receive a cure spell, however. Is his speed reduced for 24 hours (assuming he is unable to dress his wounds)?
Should the "cure spell" phrasing be taken as literal? Or should it include any faster-than-normal healing? If the former, then lesser vigor and the like would not cure the half-movement, nor would the Faith Healing spell.
Or could it be argued that the troll never took damage (rather, only nonlethal damage), and thus his speed is not cut in half?