Found this : laws of virtual world design with rules like :- The ultimate goal of a virtual world is to create a place where people of all styles of play can contribute to the world in a manner that makes the game more satisfying for everyone. - Once you open your online world, expect to keep your team on it indefinitely. Some of these games have never closed. And closing one prematurely may result in losing the faith of your customers, damaging the prospects for other games in the same genre.