Methods, computer-readable media, and specially configured machines are described for hosting an instance of a cross-realm zone that manages interaction among characters from different instances of a virtual world in a massively multiplayer online game. Different zones of the virtual world may support different numbers of realms or different combinations of realms, and some zones of the virtual world may remain as single-realm zones. When a character enters a zone, the character may be added to an instance of a cross-realm zone based on the virtual world for which the character is a member. A single cross-realm zone may handle all characters that enter the zone from a subset of realms, but not characters that enter the zone from other realms that are not in the subset of realms. Characters in a cross-realm zone might not have any affiliation or prior social connection or interaction with each other.