Osseous Cage

You conjure a prison made of bone. Creatures in the space where you create the cage can attempt a Reflex save; if they fail or don't attempt the save, they're trapped within it. The spell automatically fails if the space contains a creature larger than the spell's area. A creature inside the cage is Immobilized until it Escapes, uses an effect that can pass through solid objects, or destroys the cage. The cage has AC 10, Hardness 5, and 10 Hit Points, and it's immune to critical hits and precision damage. The osseus cage provides lesser cover from attacks that pass through the cage, either from the outside to the inside or visa versa. Heightened (+2) The spell's area grows by 5 feet on aside and it's Hit Points increase by 20.