Deterrence researchers have abandoned a one-size-fits-all approach and identified a wide range of individual characteristics (e.g., low self-control, emotional arousal) associated with the decision to offend. Comparatively less attention has been given to the moderating effects of purely situational factors on intentions to break the law. Drawing on social control and rational choice literatures, we utilized a vignette-based survey and asked a sample of young adults to report on their likelihood of driving drunk under conditions of high and low informal social control. We then explored the effects of certainty and severity of punishment on offending likelihood across both conditions. Among deterrable offenders, we found that the relationship between severity and compliance manifested only in the presence of high informal social control. Certainty was significantly and inversely associated with offending likelihood in both high and low informal social control conditions-among both deterrables and the full sample. Implications for deterrence theory are discussed.