http://web.cs.wpi.edu/~ypisan/virtualworlds/readings/tree-house-to-barracks.pdf

With 10 million active accounts, World of Warcraft (WoW) is the most successful massive multiplayer online (MMO) game out there on the market.  One reason for the success of the game is that it caters to many different types of players.  People that want to solo, people that want to tackle the end-game dungeons (player vs. environment aka PvE), people that want to kill each other (player vs. player aka PvP), and everyone in between has a place in WoW.

The interesting thing is that in order to progress through all the different dungeons  in PvE and/or move up in tournament rankings in PvP, players need to form groups (anywhere from two to forty players) and interact with other players.  On top of all that, players need to cooperate together if they want to succeed in whatever endeavors they choose to undertake.  Getting groups small groups of people (five or less) to all do the same thing might sound trivial.  However, getting groups of forty to all act in unison with everyone playing some vital role is simply amazing.  To put things into perspective, baseball teams only have nine players working together, soccer teams have slightly more at eleven players working together–this is nowhere near the forty that is needed for some situations in WoW.  Another way to look at it is to imagine working on a group project (where social loafing is not possible because the group as a whole will be penalized for one loafer) with thirty-nine other people.

With so many people working (or playing depending on how you look at it) so closely together, it’s not surprising that graph theory can be applied to the WoW playerbase.  The article linked above discusses how all different sorts of relationships between players arise from simply playing the game.  It is not uncommon at all for players to join guilds so that they can have an adequate number of people to do things.  What’s intriguing is that all the different guilds can basically be seen as clusters or components on a larger graph.  Players in a guild generally tend to have at least a weak link to every other player in the guild.  And, the longer a player stays in a guild, the more strong links that player will have with the other members.  It is also not uncommon for players in guilds to just have links to other players in their component.  Only a few players in a guild act as bridges to the larger network of players.  What’s more, in order to make sure that the guilds are stable, it is also not uncommon for guilds to have a blacklist of other players or guilds.  Therefore, every member of a guild will have a negatively weighted link to those that are on the blacklist in order to keep the peace.  The article (as well as what I can think of off the top of my head) goes on, but this is just the gist of it.

With MMO games steadily gaining popularity, it will be interesting to see the networks that develop in them.  It will also be interesting to see if there can be other uses for MMO games besides modeling social networks.