This spell creates an area of densely packed air molecules surrounding the caster. The shield provides resistance to damage from fast-moving objects passing through the shield--arrows, rocks, darts, spears, swooping attacks from aerial creatures, etc. The spell does not affect those in melee combat with the caster--however, entering melee with the caster requires one full turn during which no actions other than movement can be taken. The caster must likewise spend a full round with no other actions if she decides to move to enter melee with anyone else. The caster also gains resistance to falling damage. Attacks that are purely magical (magic missile, agonizing blast) are not affected, and the caster takes full damage from any fire, cold, lightning, radiance, or thunder damage 

The spell ends immediately if any single attack or event (a fall, for example) causes more than 30 points of damage. The caster will have resistance to the first 30 points in this case, and suffer the full effects of any remaining damage.