The Monte Carlo (MC) method was born during the Second World War. It was used in the simulation of atomic collisions which then resulted in the first atomic bomb. This chapter explores through concrete applications the usefulness of the MC method. In addition, several enhanced versions of the original MC method are discussed. The Crude Monte Carlo (CMC) method may require a very large number of samples in order to generate an acceptable result. The advanced versions of the CMC method can achieve the same level of accuracy using a smaller number of samples. Although both the crude Monte Carlo and antithetic sampling methods achieve a good accuracy, they significantly differ in the variance. In dagger sampling, multiple samples can be generated using a single random number. Monte Carlo is a powerful tool for estimating probabilities and expected values. Monte Carlo is a powerful tool for estimating probabilities and expected values.