Subsumption architecture is a type of artificial intelligence used in robotics which is based on the theory of behavior-based robotics. It is a layered approach to robotics in which each layer provides a small, simple behavior that works together with the other layers in an orchestrated way to provide more complex, higher-level behaviors. It combines both reactive and deliberative software components, allowing the robot to choose how to respond to its environment and also be able to reason and plan its actions.