The notion that substance use increases a person’s risk of future criminality or violence is reflected nearly uniformly across risk assessment instruments. Most of these risk assessment instruments, however, treat substance use as a general class. Closer inspection reveals that this approach is problematic because not all substances have an equally strong relationship to crime/violence. In particular, cannabis, opioids, and hallucinogens appear to warrant different treatment. This chapter proposes rethinking the way evaluators approach substance use in risk assessment contexts to reflect the current state of research on the relationship between substance use and crime/violence. After reviewing the literature on this topic and contemporary approaches to risk assessment, we propose a three-step framework that will enable clinicians to integrate a greater degree of nuance into their risk assessments, regardless of the specific risk assessment instruments used. We demonstrate potential applications of this framework and suggestions for communicating results through the use of vignettes.