Background The consumer behavior of mobile game players, especially the main consumingforce - millennials, has started to gain more attention as the mobile game industryhas turned into one of the most profitable entertainment fields. Nevertheless, thereis no unified model to understand the in-game purchase behavior of all mobilegames since the strengthening factors in video games are divergent subject to thegame genre. Thus, by examining in-game purchase behavior in the mainstreammobile game genre - battle royale, the authors contribute to the game research. Aim As the study's primary objective, the thesis aims to detect the strengtheningfactors of purchase behavior through the lens of the theory of consumption values(TCV) and millennial consumer preferences. Methodology The authors pursue a deductive approach to conduct a quantitative study in whicha cross-sectional survey method was selected to gather empirical data. Aregression model was created to analyze the structural relationships. SPSS wasused for the analysis of statistical data. A total of 521 responses were collected. Findings The results suggest that conditional value, emotional value, and monetary valuepositively affect the in-game purchase behavior of millennials playing mobilebattle royale games. Furthermore, customization positively moderates therelationship between conditional value and in-game purchase behavior, whereastrendiness positively moderates the relationship between emotional value andin-game purchase behavior. The results also reveal the positive direct effect onin-game purchase behavior of the proposed moderating variables, namely,customization, trendiness, and visual quality. Based on the results of this thesis,the application of TCV has been proved in the gaming field, and the authors givepractical suggestions for game companies.