Massively multiplayer online role-playing games, in short MMORPG, are a new kind of media entertainment with wide economic implications. Especially the trade of virtual items outside of the game world implies strong interests in them. This also includes virtual theft, respectively account hacks. A review of the existing literature showed a lack of empirical studies in this area of research. Therefore, this master?s thesis emphasizes these economic impacts and examines the effects of account security in free-to-play MMORPG on user satisfaction. It was assumed that the security of the user accounts is important for the commercial success of such games. The free-to-play MMORPG Runes of Magic, in short RoM, was chosen for the study. This game allows its players to freely decide whether they want to spend real money or not. 106 users of RoM participated in the online survey. The responses supported the influence of user satisfaction on the respondent?s activity and willingness to pay. Further, account security was identified as important driver for user satisfaction. Other important factors are gameplay, availability and stability of game servers, content updates and shared game experiences. Those should therefore be taken into account and/or improved by the operator of the game. Almost one quarter of the respondents was hacked within the last year. Approximately one third of them didn?t get their hacked items restored. From the user?s perspective the operating company is predominantly responsible for the protection of their accounts and items. Overall, the results of the survey imply that account security has strong effects on user satisfaction. Operators of free-to-play MMORPG should therefore improve the security of user accounts. In case of account hacks, the stolen items should be replaced completely by the operating company to prevent negative effects on their reputation and to avoid the loss of users.