Scamming in massive multiplayer online role-playing games (MMORPG) has become a significant issue in gameplay today. With the multitude of MMORPG games to choose from and the millions of users playing these games, there are significant opportunities for scammers to take advantage of unsuspecting users. The research first creates a taxonomy of online trading scams for aiding developers to prevent scamming in games. This taxonomy focuses on the targets, objectives, and strategies scammers use in MMORPGs. Secondly, it introduces a scam mitigation method to reduce opportunities for scams within the MMORPG trading environment. The mitigation method implements three services: Barter, Market, and Contract. Using the services can provide a trustworthy venue for trading, prevent common scams, and provide better overall gameplay for current and future users.