Systems and methods for automatically injecting effects in cyber-physical systems and their simulations are provided herein. In one example, the cyber-physical system under test can include one or more watch-point monitors that can analyze messages between components of the system to determine the presence of one or more particular patterns present in the messages being passed between components of the system during operation. In one or more examples, upon detection of one or more conditions matching a watch point, the systems and methods presented herein can activate an effect and inject it into the cyber-physical system under test based on the detected watch point. In one or more examples, the systems and methods can provide a domain-specific “effects language” (EL) that can allow a user to specify a watch point and an effect corresponding to the watch point.