Drawing on the Self-Development Theory (SDT), this study examines the relation between the factors that motivate online gaming and the effects of addiction, shyness, and loneliness. We have modified the SDT theory by adding intrinsic and extrinsic factors to measure the degree of its effect on addiction in online gaming settings. Next, we develop a special instrument to measure gamers’ experience and their level of addiction. The sample is 671 online gamers who participated in an online survey. A confirmatory factor analysis and structured equation modeling tests are conducted to identify reliable factors and the goodness of fit of the research model. The findings show that the effect of addiction on shyness and loneliness is minor. Furthermore, loneliness is affected mostly by anxiety of others. In addition, the challenge of meeting the goals of gaming has the greatest effect on addiction. The study offers important implications for decision makers among family members such as parents and among society in general such as policy makers to avoid side effects of online gaming.