As the complexity of a detection algorithm increases, analytic performance evaluation becomes increasingly difficult and is often intractable. In such cases, Monte Carlo sunulations can be used, but they often require an excessive amount of computation. As a means of reducing this computation, importance sampling has been applied with great success to simulations of digital communications receivers. In this paper, importance sampling strategies for the simulation of random signal detectors are presented. These strategies are shown to provide considerable computational savings over conventional Monte Carlo simulations. Additionally, simplicity and ease of use are emphasized in the development of these strategies.