While responsible decisionmaking has been a focus of prevention programs targeting young people, the programs tend to emphasize making informed decisions about ones own health. The current study explored the decisionmaking of young people concerning their friend’s experimentation with alcohol, tobacco, and other drugs. Participants were 2,697, 5th through 12th grade students who answered questions about 4 vignettes describing a friend’s smoking, drinking, or other drug use behavior. Participants identified intervention strategies they would likely take for each vignette. Results of statistical analyses indicated age and gender differences in intervention strategies. Younger students were more likely than older students to endorse proactive strategies while females were more likely than males to talk with friends about the behavior and were less likely to ignore the behavior or cease the friendship. Among students aged 13 years and older, the more dangerous the substance, the more likely they were to use intervention strategies. The findings suggest that it may be effective for prevention programs to endorse an ethic of social responsibility encouraging young people to intervene in the alcohol, tobacco, and drug use of friends. Tables, references