The Handbook of Responsibility provides an overview of topics and positions in international responsibility research. It addresses the history and etymology of responsibility and explains why the concept of responsibility is part of the fundamental vocabulary of ethical thinking. Whenever responsibility is discussed, terms such as freedom, attribution, guilt, or duty play a crucial role. Furthermore, different types and forms of responsibility, such as individual and collective responsibility, are examined. The reader is familiarized with the key areas of action, which include political and legal responsibility, as well as the role of the principle of responsibility in education, media, technology, and science. Last but not least, it addresses the contribution that the principle of responsibility makes to addressing challenges related to human rights.