In computing, a Monte Carlo algorithm is a randomized algorithm whose output may be incorrect with a certain (typically small) probability. Two examples of such algorithms are Karger–Stein algorithm and Monte Carlo algorithm for minimum Feedback arc set.
The name refers to the grand casino in the Principality of Monaco at Monte Carlo, which is well-known around the world as an icon of gambling. The term “Monte Carlo” was first introduced in 1947 by Nicholas Metropolis.
The related class of Las Vegas algorithms are also randomized, but in a different way: they take an amount of time that varies randomly, but always produce the correct answer.
It is not possible for a Monte Carlo algorithm to be converted into a Las Vegas algorithm even if there exists a procedure to verify that the output produced by the algorithm is indeed correct. Even if a resulting Las Vegas algorithm were to repeatedly run the Monte Carlo algorithm there is still no guarantee that any of the runs produces an output that can be verified to be correct.