Guild Wars Interview

ComputerAndVideoGames.com has conducted an interview with ArenaNet's Jeff Strain, in which the producer answers quite a few questions about their upcoming fantasy MMORPG, Guild Wars. A snip:
Q: So how can Guild Wars offers quests that change the game world, especially when cooperative multiplayer play is so central to the game?

A: When you enter a mission or quest area in Guild Wars you and your party of up to 8 people are put into a part of the world that is uniquely created and populated just for you. The way that works is the game servers will look at everyone in the party and examine every quest you've completed, every NPC you've talked to, every item in your inventory and so on, and build a large matrix of everything you could possibly see in the quest. Then the servers systematically remove everything that would not make sense to you and your party. For instance, if you've seen an NPC die but one of your friends hasn't, we'll make sure that NPC plays no part in the quest. So essentially we remove all the inconsistencies and dynamically populate the quest based on what you have seen or not seen in the game.

Here's a concrete example. In the Ascaron missions after the Great Searing [the destruction of your home city by invading forces] one of your missions is to track down a Prince who has taken a batallion of the Ascaron army out to establish a forward post. Your quest is to find him, and when you do he's surrounded by the enemy. If you rescue him he establishes his forward base. From then on every time you enter that part of the world the Prince is there, and that opens up lots of new quests and game content for you to explore. In other MMOs you couldn't do that kind of quest, because for some people he would be there and for others - who hadn't done the quest - he wouldn't. In this situation you can take friends who haven't completed that specific quest to the forward base, but if they go there themselves it will not be there. As well as getting rid of inconsistencies, we want to make sure everyone gets the benefit of party member's accomplishments.

So in Guild Wars the world is constantly changing and evolving as a result of your actions. That's the most important aspect in creating a believable RPG world, that sense of 'I'm having an impact on this world'. You can't do that in a traditional MMORPG.