Recently, the design and development of multiagent systems (MASs) has become increasingly concerned with the recognition that they will be used in a dynamic and open environment. In such environments, it is a very difficult and complicated task to anticipate all possible runtime situations at design time. In order to respond to changes in this environment it is necessary to allow the system to provide dynamic responses at runtime. This work is concerned with one particular aspect of such responses. In this book, we explicitly identify, clarify and address the problem of dynamic assignment of rights, responsibilities (R&Rs) and sanctions to external agents in normative MASs. We propose two alternative methods for dynamic assignment of R&Rs and sanctions to external agents, along with a formalism to represent a commonsense understanding of our solution. The implementation of an agent auction that we present allows us to examine and compare the functionality of our two methods under various scenarios, including different runtime occurrences and various types of legal notions.