‘Alcohol-fuelled violence’ has been a concerted focus of recent criminal justice policy debates and legal reform. This study was motivated by the prominence of an essentialised paradigm that claims a direct causal relationship between use of alcohol and other drugs (AOD) and crimes of violence and other offending, and asserts that AOD should routinely be regarded as an aggravating factor. This approach belies the wide variety of ways in which AOD ‘intoxication’ features in the content and operation of Australian criminal laws. The study analysed more than 500 crime-related statutory provisions which attach significance to a person’s ‘intoxication’, and more than 300 court decisions involving evidence that the accused, the victim or a witness was ‘intoxicated’ at the time of the alleged offence. These analyses found that significance is attached to ‘intoxication’ for a wide variety of criminal justice purposes – including to enliven police powers, to evaluate the veracity of witness testimony, to assess criminal responsibility and to determine punishment. In both statutory formulations and criminal court adjudication, there is a widespread problem of under-definition and imprecision as to meaning. ‘Intoxication’ is often assessed on the basis of highly subjective criteria – in contexts as diverse as public order policing and assessments of victim credibility in sexual assault trials. In the absence of legislative guidance, courts tend to assign only a relatively marginal role to medical/scientific expert evidence, and frame the question of whether a person was relevantly ‘intoxicated’ as one that can be answered by applying ‘common knowledge’ about AOD effects. Given the magnitude of the consequences that can flow from criminal justice decisions, the study recommends that consideration be given to standardising definitions of ‘intoxication’, with greater attention paid to evidence-based insights drawn from the scientific and social scientific literature.