This chapter describes steps that can be taken to advance deterrence theory using comprehensive deterrence theory (CDT). It discusses, for example, the possibility of identifying second-level principles that integrate CDT’s first-level principles. There is, too, the possibility of advancing CDT by investigating causes of the intrinsic elements and modifying the principles or creating new ones. Another avenue to pursue entails identifying how deterrent processes and effects may vary across different individuals, groups, conditions, types of crime, and units of analysis. Still other avenues involve incorporating offending theories into CDT and contemplating how deterrence processes may vary when considering offending onset, persistence, and desistance.