Self-determination theory (SDT; Intrinsic motivation and selfdetermination in human behavior, New York, 1985; The oxford handbook of human motivation, New York, pp 2012) is a broad motivational theory that has been developing for the last four decades. The theory makes the distinction between intrinsic and extrinsic motivation and identifi es three basic psychological needs that are essential for well-being. When people are intrinsically motivated, they engage in an activity because the activity itself is interesting, enjoyable, and congruent with their selves. In contrast, when people are extrinsically motivated, they engage in an activity because the activity is instrumental in obtaining rewards or avoiding punishments. In this chapter, we will discuss digital games within a SDT framework, with a focus on how satisfaction of basic psychological needs in games can enhance user experience. We start with the behavioral psychology principles and the use of rewards in games that fuel extrinsic motivation. Next, we discuss intrinsic-extrinsic motivation and the three basic psychological needs-autonomy, competence, and relatedness-that facilitate intrinsic motivation and enhance player experience. Finally, we discuss some basic game features and their relation to basic needs.