The terms "play, recreation, and leisure" can evoke thoughts of frivolity, fun, sociability, competition, slothfulness, or idleness. However, there is substantial evidence that what people do in their discretionary or free time has important developmental and health implications. In this article, the authors examine how play, recreation, and leisure contribute to adolescent development and the conditions that facilitate that development. They discuss positive developmental benefits associated with filling free time in positive ways. Although there are differences in the use of the terms "play, recreation, and leisure," the authors avoid the semantic quagmire and use the term "leisure" to convey the positive ways that adolescents can fill their free time. As they discuss these developmental outcomes, they describe in more detail the characteristics of leisure pursuits and experiences that contribute to these outcomes. They begin their discussion with a recent story from the "Christian Science Monitor" about two parents who started a nonprofit organization, Plugged In (PI). The mission of PI is to enable youth to have a positive effect on their world through music. The story of PI serves as a platform to begin a discussion of how leisure contributes to youth development. (Contains 31 notes.)