Vertigo Field

You create a field of swirling patterns of color, light, and motion. Creatures in the area stagger as the barrage of sensations overloads their senses and leaves them overcome with vertigo. This spell creates a field of illusory magic that hampers the movement and senses of any creature that enters it. The area within the field counts as difficult terrain. Attacks made through or from inside the field have a 20% miss chance. A creature that begins its turn inside the field must make a Fortitude save or become nauseated for 1 round. Once a creature fails this save, it does not need to make another save against this effect. When you cast this spell, you can choose for this nauseating effect not to apply to a number of allies you designate less than or equal to your caster level. Those allies still treat the vertigo field as difficult terrain and have the 20% miss chance on attacks.