Over recent years, the notion of agency has claimed a major role in de?ning the trends of modern research. In?uencing a broad spectrum of disciplines such as sociology, psychology, philosophy and many more, the agent paradigm virtually invaded every sub?eld of computer science, because of its promising applications for the Internet and in robotics. Multi-agent systems (MAS) are communities of problem-solving entities that can perceive and act upon their environments to achieve their individual goals as well as joint goals. The work on such systems integrates many technologies and concepts in...