Meta-architectures, also known as reflective architectures, are a specific type of software architectures that are able to inspect their own structure and behavior, and dynamically adapt at runtime, thus responding to new user requirements or changes in their environment. In object-oriented programming, these architectures rely on a small set of core concepts that provide them the means to describe themselves, thus becoming "closed". These three core patterns can be found in almost every object-oriented meta-architecture: Everything is a Thing, Closing the Roof, and Bootstrapping. By delving into the inherent problems they try to solve, and the forces that shape those problems, a developer will improve his ability to adequately make architectural and design choices to build and evolve systems with high-adaptability needs.