Although the majority of research focuses on the risks and disadvantages of online gaming, the present authors suggest that online games also represent new ways of satisfying basic human needs within the conditions of modern society. The aim of our present study was to reveal and operationalize the components of the motivational basis of online gaming. A total 3,818 persons (90.6% males; mean age 20.9 years, SD = 5.81) were recruited through websites providing online games. A combined method of exploratory and confirmatory factor analysis was applied. The results confirmed our preliminary model as we identified seven motivational factors (social, escape, competition, coping, skill development, fantasy, and recreation), which were used to develop the 27-item Motives for Online Gaming Questionnaire (MOGQ). The seven dimensions identified seem to cover the full range of possible motives for gaming, and the MOGQ proved to be an adequate measurement tool to assess these motives.