Criminology has traditionally emphasized the offender, relegating theory, research, and policy on target decision-making to a place of relative unimportance. I advocate a different view. In choice theory, offenders prefer quick and easy reward at little risk, acting with target vulnerability very much in mind. I use choice theory concepts and assumptions to account for target precautionary behavior. The principles of certainty, swiftness, and severity can be developed to explain not only when people will act to limit vulnerability, but also suggest the kinds of precautions that tend to be chosen reliably. Low self-control, a source of victimization risk, lessens feelings of certainty of victimization and fosters a preference for the easiest and most immediately gratifying methods of protection. In addition to stimulating theorizing and research to improve the usage and consistency of precautionary behavior, this theory also offers insights about controversial choices to acquire defensive weapons.