Phantom chasm is an illusion spell learned by some wizards early in their training. Phantom chasm, when cast, creates the image of a bottomless pit five feet in diameter within 100 feet of the wizard. Though it is only an illusion, creatures standing over the chasm find it so realistic that they may suffer actual mental trauma, convinced that they are plummeting to their deaths. Regardless of whether or not the illusion works, creatures caught within find themselves immobilized from the shock for a brief moment. The spell requires a vast amount of effort on the part of the caster, meaning it can only be used once per day.