In computing, a Las Vegas algorithm is a randomized algorithm which is correct; that is, it always produces the correct result. Thus, the random bits used only influence the resources used by the algorithm. A simple example is randomized quicksort, where the pivot is chosen randomly, but the result is always sorted. An alternative definition of a Las Vegas algorithm includes the restriction that the average-case running-time must be finite.
Compare to the Monte Carlo method where the resources used are constant, but the random bits influence if the result is correct.