In games and digital media, the "magic circle" is the space in which the normal rules and reality of the world are suspended and replaced by the artificial reality of a game world. As noted by Edward Castronova in Synthetic Worlds: The Business and Culture of Online Games, the boundary delineating this space "can be considered a shield of sorts, protecting the fantasy world from the outside world". Instead of being impenetrable, however, an examination of contemporary virtual worlds reveals that the magic circle is actually quite porous. More directly, there appears to be a relationship between virtual worlds and the outside world. Even though virtual worlds display a range of attributes that are unique to their realm, they also exhibit characteristics deriving from the outside world. Cast