Universities must prepare students for a complex world, but current mental health levels impair student outcomes. Increased concern over student wellbeing has fostered the demand for positive education interventions -- a relatively new topic requiring more research. We tested a positive psychology wellbeing intervention imbedded in undergraduate psychology classes with three studies and 469 participants. Intervention outcomes across three years indicate improvements in wellbeing, positive affect, negative affect and clinical wellbeing categories. Comparisons with an active control indicated the intervention buffered against semester stress. Practice frequency had little effect on wellbeing, however wellbeing gains were higher for students with low baseline wellbeing and those who valued happiness more -- suggesting positive education interventions have greater value for some students. This research has important implications for student wellbeing, indicating that imbedded wellbeing programs can improve student wellbeing with minimal resources and low stigma.