This study constructs a theory which explains how video game players purchase different types of in-game goods. Instead of formulating and verifying hypotheses, we conducted an inductive approach through qualitative data analysis using grounded theory. In this study, we classified six types of in-game goods into three categories, functional-based goods, probability-based goods, and ornamental based goods. After acknowledging the heterogeneity of each category of in-game goods, we developed our grounded theory by conducting 21 in-depth interviews. We found that players purchase functional-based goods, probability-based goods, and ornamental based good for different motives and through the different purchase process. While the non-flow experience is the key trigger which leads to purchase functional-based in-game goods, the size of the reference group determined by the exposure inside the game leads to purchase ornamental-based goods. First, purchasing functional-based goods is a strategy of pulling players back to the flow experience. Second, purchasing probability-based goods is a compromise for purchase restrictions. Third, purchasing ornamental goods is a synergism of intrinsic motivations and exposure.