Research provides strong support for the theory that drug market participants are often involved in violent retaliation because they lack access to formal mediation. Yet retaliation is not always violent. The existing drug market literature offers few counts, estimates, or stories of non-violent retaliation, and no single theory specifies the variable conditions that determine which form of retaliation occurs. This paper contributes to criminology by drawing on the necessary conditions perspective and qualitative data obtained from drug dealers to provide the conceptual and theoretical foundation for future criminological work, including the development of theories that explain variability in retaliatory forms, research that demonstrates whether any given theory is supported by data, and criminal justice policies that draw on theoretical and empirical knowledge to reduce all forms of drug market retaliation violent and non-violent. Table and references (Published Abstract)