Intelligent agents provide simulations a means to add lifelike behavior in place of manned entities. Generally when developed, a single intelligent agent model is chosen, such as rule based, behavior trees, etc. This choice introduces restrictions into what behaviors agents can manifest, and can require significant testing in edge cases. This book presents the use of the UBF in the AFSIM environment. The UBF provides the flexibility to implement any and all intelligent agent models, allowing the developer to choose the model he/she feels best it's the experiment at hand. Furthermore, the UBF demonstrates several key software engineering principles through its modular design, including scalability through reduced code complexity, simplified development and testing through abstraction, and the promotion of code reuse.