The target is forced to switch out and be replaced with a random unfainted ally. Fails if the target is the last unfainted Pokemon in its party, if the target used Ingrain previously or has the Suction Cups Ability, or if the user's level is lower than the target's and X * (user's level + target's level) / 256 + 1 is less than or equal to (target's level / 4), rounded down, where X is a random number from 0 to 255.