Organized Play gaming systems are a gaming format within the table-top role-playing game community that provide the opportunity for play by an extended community within a shared universe. In contrast to traditional isolated role-playing games, organized play allows and encourages players to develop characters that can be played at games run by many different game masters, but which share a game world and campaign setting, as well as a plot line that is overseen by a central core of professional or volunteer editors and contributors.
Many organized play systems serve a dual role of providing a creative outlet for highly involved volunteer contributors while also serving as a marketing tool for the publisher of the game system that is the focus of the living campaign. While the earliest organized play systems, called Living Campaigns, were run by the RPGA (Role Playing Gamer's Association), now a division of Wizards of the Coast, many groups around the world run active organized play which are independent or sponsored by other publishers.