There is a broad range of forensic issues for physicians and other professionals interested in addictive illness. For many clinicians, the most challenging aspect of forensic matters is their origin in the law, which as a field and as a way of thinking may feel alien to the medical practitioner. To successfully negotiate forensic issues, practitioners must apply certain principles. Forensic work necessitates understanding the specific legal questions that arise in each forensic context, and involves learning the relevant definitions, criteria, and legal requirements and laws that pertain because clinical definitions and clinical reasoning will not be sufficient or accurate. In performing forensic evaluations, the practitioner must eschew the wish to help the examinee, concentrating on the neutrality of the examiner. Questions of volition in addiction are discussed. Subjects are then organized into the important areas of interest within the civil, criminal, and regulatory environments of forensic work. The authors have included discussion of new and/or emerging areas in the field. [ABSTRACT FROM AUTHOR]