Trends toward lethality -- Human failings in the battlefield -- Related philosophical thought -- What people think : opinions on lethal autonomous systems -- Formalization for ethical control -- Specific issues for lethality : what to represent -- Representational choices : how to represent ethics in a lethal robot -- Architectural considerations for governing lethality -- Design options -- Example scenarios for the ethical use of force -- A prototype implementation -- Appendix A: Relevant laws of war -- Appendix B: Acronyms -- Appendix C: Notation.