Packy & Marlon, an interactive adventure video game that uses experiential learning to improve self-management of diabetic children and adolescents, was evaluated in a six-month controlled trial. In the game, youngsters play the role of a character that has diabetes; they manage their character's blood glucose monitoring, insulin use, and food selections for four simulated days, while the character tries to save a diabetes summer camp from marauding rats and mice. Keeping their character's blood glucose within the normal range, through appropriate insulin and food, helps players win the game. Study participants were young people ages 8 to 16 who were outpatients of diabetes clinics at Stanford University Medical Center and at a Kaiser Permanente clinic. Each participant received a video game system at an initial clinic visit and was randomly assigned to receive either Packy & Marlon (treatment grou