The
gambler's fallacy, also known as the
Monte Carlo fallacy or the
fallacy of the maturity of chances, is the mistaken belief that, if something happens more frequently than normal during some period, it will happen less frequently in the future, or that, if something happens less frequently than normal during some period, it will happen more frequently in the future (presumably as a means of
balancing nature).
In situations where what is being observed is truly random (i.e.,
independent trials of a
random process), this belief, though appealing to the human mind, is false. This
fallacy can arise in many practical situations although it is most strongly associated with
gambling where such mistakes are common among players.