Abstract: What determines the entertainment value of a game? Ely, Frankel and Kamenica (2015) develop a formal model of suspense and surprise for analyzing entertainment value. We plan to apply their methodology using data from the video game League of Legends, a popular online game that combines real-time strategy, role-playing game elements and team coordination. League of Legends presents an ideal context to study the effects of suspense and surprise on enjoyment and engagement in leisure activities. In each of League of Legends’s matches the two potential outcomes are that one team (say, the Blue team) wins or loses. A period in a match has more suspense if the variance of the next period's probability that Blue Team wins is greater. A period has more surprise if the probability that Blue team wins is further from the last period's probability. Unlike typical sporting events, the people engaged in the game are predominantly players, not fans, and they exhibit measurable behavior. This allows us to link suspense and surprise of a match to an immediate objective behavior, such as player continuation. In addition, self-reported responses to “fun” surveys are recorded and constitute a way to measure enjoyment. In order to perform this analysis, we have acquired a unique dataset containing nearly 200 variables from Riot Games Inc., characterizing the minute-by-minute state (position, gold, experience, etc.) of approximately 10 million games. Our data also indicate whether players played prior to the observed game and continued with additional games afterward. For a small subset of the data, we also observe surveyed enjoyment.