Rocky ground, stone floors, and similar surfaces shapes themselves into long, sharp points that blend into the background. The spike stones impede progress through an area and deal damage. Any creature moving on foot into or through the spell’s area takes 1d8 points of damage for each 5 feet of movement through the spiked area. In addition, ground speed through the spell’s area is reduced by half.

Any creature who sustains damage from this spell must also succeed at a Reflex save or suffer injuries to its feet and legs that slow its speed by one-third. This movement penalty lasts 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 at a Heal check against the spell’s save DC.

Spike stones is a magic trap that can’t be disabled with the Disable Device skill.