  There is no single, widely agreed upon theory that explains when an agent is or is not responsible for something that happens in the world. Judgments of responsibility are normative, and may depend on other normative facts specific to the particular sort of action or practice in question. For instance, facts that might limit one's responsibility for signing or violating a contract might fail to limit one's responsibility for killing someone. So the effect of coercion or its kin (duress, extortion) may differ depending upon the sort of action for which one seeks to limit one's responsibility, or upon the moral context in which one acted. Nonetheless, a few central cases and some general tendencies can be given with some confidence.