Prior Fault Criminalization is the first monograph exploring the contested concept of 'prior fault' and its articulation within criminal law offences and defences. The ambition of such rules may be stated simply: a defendant should not escape criminal sanction through an appeal to their own prior blameworthy conduct. Thus, for example, where a person puts themselves in a state of incapacity through drink or drugs, they should not be able to rely on that state to explain later 'mistakes' causing harm; or where a person manipulates another into attacking them, they should not be able to rely on that attack to justify force in 'defence'.The book provides comprehensive coverage and critique of the manifestation of prior fault rules in the laws of England and Wales along with comparative examination of other common law and civil law jurisdictions. It reveals an expansive field of criminal rules characterised by incoherence, inconsistency, and unfairness-and a series of appeals to scientific and clinical assumptions that are wholly misconceived. The book identifies frameworks for theoretical reconstruction of such rules, drawing on findings from the extant psychological and neuroscientific literature as well as a set of original empirical studies to identify more robust markers of blame, which in turn inform doctrinal reform proposals for jurisdictions employing prior fault principles in their criminal law.