Fair Opportunity and Responsibility lies at the intersection of moral psychology and criminal jurisprudence and analyzes responsibility and its relations to desert, culpability, excuse, blame, and punishment. It links responsibility with the reactive attitudes but makes the justification of the reactive attitudes depend on a prior and independent conception of responsibility. Responsibility and excuse are inversely related; an agent is responsible formisconduct if and only if it is not excused. As a result, we can study responsibility by understanding excuses. We excuse misconduct when an agent's capacities or opportunities are significantly impaired, because these capacities and opportunities are essential if agents are to have a fair opportunity to avoidwrongdoing. This conception of excuse tells us that responsibility itself consists in agents having suitable cognitive and volitional capacities - normative competence - and a fair opportunity to exercise these capacities free from undue interference - situational control. Because our reactive attitudes and practices presuppose the fair opportunity conception of responsibility, this supports a predominantly retributive conception of blame and punishment that treats culpable wrongdoing as thedesert basis of blame and punishment. We can then apply the fair opportunity framework to assessing responsibility and excuse in circumstances of structural injustice, situational influences in ordinary circumstances and in wartime, insanity and psychopathy, immaturity, addiction, and crimes ofpassion. Though fair opportunity has important implications for each issue, treating them together allows us to explore common themes and appreciate the need to take partial responsibility and excuse seriously in our practices of blame and punishment.