For a game to be laveled MMORPG, which stands for Massive Multiplayer Online Rol Playing Game, it may be enough that the game is played online, that players meet with the form of avatars, that the avatars have some character and they can do together things like missions and adventures, embeded within a fictional story.
These MMORPG games may reach the status of Game World if all interactions relevantly related to the game can be performed within the game.
There are also Online Competitive Games in which players either do not interact by means of avatars, or in which the avatars interactions are restricted to the game competitive matches which might be within a tournament or not. Were there be a story line relatable to one of these competitive games, this story line is not played Online. And, these Online Competitive Games do not aspire to be Game Worlds.
By now Guild Wars has some features of a MMORPG and some features of an OCG, but it is not a Game World, because a great number of interactions are expected to be covered by means out-game interactions, like it is web interaction. For example, for a Rol Playing interaction like it is trade, there are web Action Houses. For a Rol and Competitive interactions as Guilds are, there are guild webs, guilds forums, and the guilds rank list is also an out-game, web based, list.
The question I would like to ask is, if you think that GW will ever become a Game World, with all or most of the relevant-to-the- game interactions being possible to be accomplished ingame. Thus making the RPG aspect a wholy ingame interaction; say that there should be an Auction House to make trade a fully ingame interaction. As well as making the OCG a wholy ingame interaction; say that a Guilds rank listing should be ingame and there should be ingame features like information boards about Guilds, and more Guilds' construction features. so that the OCG and the RPG were fully integrated ingame, enough as to relevantly becoming a Game World.
Or, if you think that GW becoming a Game World is irrelevant for GW, and it is better just to have a partial hibrid of OCG and RPG which full integration and completeness is get by means out-game web interactions.
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What for do you talk about eBay?