A device of but about the size of a large die—perhaps ¾ of an inch across—the cube of force enables its possessor to put up a wall of force 1" per side around his or her person, and this cubic screen is impervious to the attack forms shown on the table below. 

The cube has 36 charges, and each day this energy is restored. 

The holder presses one face of the cube to activate or deactivate the field:

When the force screen is up, the following attack forms cost extra charges from the cube in order to maintain the integrity of the screen. 

Note that these spells cannot be cast either into or out of the cube:

The cube of force can be of any hard mineral, ivory or bone.