This Open Access book is about the risks and the ethics of human germline gene editing, i.e., the possibility to make heritable changes to the DNA of early human embryos or germ cells. Is there something particularly morally problematic about editing the human germline? Is there something unique about germline editing, and, if so, does this suggest that we ought not to edit the human germline, or only in particular circumstances or for particular purposes? What would be a wise and responsible approach to editing the human germline from a moral perspective? The book has three broad aims. First, to present an inclusive map over the current scholarly debate on the ethics of human germline gene editing. Second, to provide a philosophical and critical guide to the various ideas and arguments in this debate. Third, to apply an ethics of risk perspective and defend a morally cautious position on human germline gene editing.