2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/88969A game in which one player makes unitary transformations of a simple system, and another seeks to confound the resulting state by a randomly chosen action is analyzed carefully. It is shown that the second player can reduce any system to a completely random one by rotation through an angle of 120 degrees, about an axis chosen at random. If, on the other hand, the second player is forced to behave ``classically'' by reducing the wave function, then the first play retains an advantage, which the second player may eliminate by repeated measurement using randomly selected bases.Created with Scientific WordQuantum Physicstext