Are there reasons to think drug problems and policy could change rapidly over the next 5 to 20 years? The authors believe so. Based on the deliberations of a colloquium, 3Drug Use and Drug Policy Futures,2 held at RAND in August 2002, this issue paper lays out some reasons behind this belief and its implications for current policy. The authors delineate the factors influencing drug problems and policy that could grow stronger or weaker in the coming years and drive problems and policy off their current course; other assumptions that have been valid in the past but may be more vulnerable to reversal, or at least more vulnerable than is commonly assumed; and 3wild cards2 for low-probability, high-consequence developments that may occur in drug use and drug policy, offering some plausible examples to illustrate the concept. The colloquium demonstrated that current decisions regarding drug policy should be informed by a broad range of possible futures. The authors describe the different types of implications that might be drawn and some examples illustrating their importance. More generally, the examples offered here suggest that everyone could be better off in the long run if the time and attention devoted to analyzing past trends and the current situation were supplemented by more formal attention to the future.