Background: Men are more likely than women to perpetrate serious violence when they have consumed alcohol, but alcohol does not affect all men in the same way. This paper considers young adults’ attribution about agency (the capacity to act) in men's drunken violence. Methods: Interviews about alcohol use in night-time venues, streets or private parties were conducted with 60 young adults aged 18–24 in Melbourne, Australia, and analysed thematically. Participants included seven men who identified as having initiated violence when drunk. Results: Some interviewees stated that men chose to be violent, or that men's violence when they were drunk was purposeful and therefore involved some component of choice. However, much alcohol-related violence enacted by young men was understood (both by men who reported violence and by other young adults) as impelled by forces outside their control. These forces were: diffusely defined effects of drinking alcohol; proclivities of men and masculinity, and the interaction of alcohol and men's bodies to override capacity for judgement and produce an irresistible urge to fight. The latter was at times explained as caused by the mutually reinforcing actions of alcohol and testosterone, providing a particularly persuasive account of men's violence as biologically-determined. Conclusion: These categories encapsulate a set of discursive resources that contribute to the rationalisation, naturalisation and production of men's violence. Participants tended to regard alcohol, masculinities and testosterone as inciting violence predictably and consistently, suggesting that men themselves had relatively little agency over its occurrence. In contrast, research evidence indicates that these actors do not cause violence in any uniform way and that their effects are contingent on changing configurations of factors. Highlighting discrepancies between young adults’ understandings of responsibility for men's drunken violence, and those expressed in research, presents additional opportunities for intervention.