Abstract: Target testing code based on failure paths can improve hit rates and reduce memory consumption. Aggregating failure signatures into clusters can help to identify additional tests to perform. Further, the signature clusters can be used to automate testing of a video game by, for example, identifying tests that test elements of the video game that are common to the signatures within a cluster and automatically executing the tests without user involvement. The results of the tests can be used to modify the video game state. The process of testing and modifying the video game can be performed iteratively until a signature for the video game no longer matches the cluster.