Proponents of drug legalization argue that the advantages of such a policy lie primarily in three major areas: economic, criminal justice, and health. The primary argument in favor of retaining current drug laws is that legalization will open the "floodgates" and increase drug consumption and the problems associated with it, namely, addiction, crime, and sexually transmitted diseases. Outlining a study to explore the effects of drug legalization is difficult, not only because the central concepts of legalization are inextricable, but because there are a multitude of steps to be taken before full legalization can be realized. This essay identifies these steps, and potential tests for each are proposed. The steps identified are the medical use of marijuana and the recreational use of marijuana. Advancement to subsequent steps within the legalization debate would only occur if the evidence from previous steps was supportive. If legalizing recreational marijuana use led to significant amounts of increased use and notable growth in criminal activity, for example, expanding the legalization domain to other, more serious drugs of abuse would clearly not be recommended. Nevertheless, the plan to legalize other drugs would follow the same paths as those for medical and recreational marijuana. At each step of legalization, scientists should evaluate the consequences and determine, based on the objective evidence, whether a next step is warranted. Given the impact legalization would necessarily have on the public, their participation at each step is critical. Legalization reforms need not be executed in every jurisdiction across the country. Certain jurisdictions whose populace is more inclined toward legalization would make excellent test sites. Although the results would not necessarily be generalizable to other jurisdictions, positive results in one site may lead to the consideration of legalization in others. The process of legalization is best approached cautiously, and it should be retained only if objective empirical evidence suggests that it should. 41 references