Blade Barrier

You create a vertical wall of whirling, razor-sharp blades made of magical energy. The wall appears within range and lasts for the duration. You can make a straight wall up to 100 feet long, 20 feet high, and 5 feet thick, or a ringed wall up to 60 feet in diameter, 20 feet high, and 5 feet thick. The wall provides three-quarters cover to creatures behind it, and its space is difficult terrain. When a creature enters the wall's area for the first time on a turn or starts its turn there, the creature must make a dexterity saving throw. On a failed save, the creature takes 6d10 slashing damage. On a successful save, the creature takes half as much damage.

This spell creates a wall of whirling blades up to 20' long per caster level, or a ringed wall of whirling blades with a radius of up to 5' per two levels. Either form will be up to 20 ft. high (as allowed by available space). Any creature passing through the wall takes 1d6 points of damage per caster level (maximum 15d6), with a save vs. Death Ray reducing damage to half.

If the caster evokes the barrier so that it appears where creatures are, each creature takes damage as if passing through the wall. Each such creature can avoid the wall (ending up on the side of its choice) and thus take no damage by making a successful save vs. Death Ray.

A blade barrier provides cover (+4 bonus to Armor Class) against attacks made through it.