Wall of thorns

Wall of thorns is a conjuration spell that calls a dense, thorny thicket into existence.

Effect
The wall of thorns spell creates a barrier of very tough, pliable, tangled brush bearing needle-sharp thorns as long as a person's finger. Any creature forced into or attempting to move through the wall of thorns takes damage as he or she moves through it.

The caster can make the wall as thin as five feet thick, which allows him or her to shape the wall as a number of ten-by-ten-by-five-foot blocks. This has no effect on the damage inflicted by the thorns, but any creature attempting to break through takes that much less time to force its way through the barrier.

Any creature within the area of the spell when it is cast takes damage as if it had moved into the wall and is caught inside. In order to escape, it must attempt to push its way free, or it can wait until the spell ends. Creatures with the ability to pass through overgrown areas unhindered can pass through a wall of thorns at their normal speed without taking damage.

A wall of thorns can be carefully breached by slow work with edged weapons. Chopping away at the wall creates a safe passage one foot deep for every ten minutes of work. Normal fire cannot harm the barrier, but magical fire burns away the barrier in ten minutes.