If you work in design for behavior change programs, you’ve undoubtedly had a client request “gamification” as a way to jazz up their deliverables. Unfortunately, there often isn’t a deep understanding of what gamification is, why it can be effective, and why it might not always be the right choice. In this presentation, I take a step back to consider “gamified design” and the psychology behind how it can more effectively engage users and help them change behaviors. I then focus specifically on badges, one of the more popular game elements that is increasingly used in digital experiences as diverse as the Starbucks app (commerce), Duolingo (education), and Fitbit (fitness). New badge applications are being introduced all the time, but many of them won’t achieve their intended goals of changing behaviors because they were not designed in concordance with the underlying psychology. I provide a brief overview of self-determination theory, a unified theory of motivation that includes the universal psychological needs an engaging experience helps fulfill, and talk about how badges can fulfill each of these needs. Drawing on this theory as well as lessons from neuropsychology, universal design for learning, and behaviorism, I then talk about how badges can reinforce desired behaviors and discourage non-desired behaviors when applied thoughtfully. We look at common pitfalls in the application of badges in behavior change programs, and strategies to avoid those. Then we discuss best practices, rooted in psychology, for maximizing the efficacy of badges. Throughout, I’ll draw on case studies showing badges used well and poorly, highlighting the specific reasons why they work (or not). The content interweaves psychological theory and research with real-world examples to reinforce not just what works, but why.