Difficulty is a tough aspect to balance in video games. Some people prefer video games that present a challenge whereas others enjoy an easy experience. To make this process easier, most developers use dynamic difficulty adjustment (DDA). The idea of DDA is to adjust the difficulty of a game in real time according to player performance. For example, if player performance exceeds the developer’s expectations for a given difficulty level, the game’s DDA agent can automatically raise the difficulty to increase the challenge presented to the player. Though useful, this strategy is limited in that only player performance is taken into account, not how much fun they are actually having.