If you look at a game like Half-Life 2 or Call of Duty, their developers can really custom build scripted areas with no fear that gameplay is going to trickle out of that area. 'The problem when you build emergent spaces,' Levine says, 'is that the amount of testing and rebuilding is much higher, because areas have to be applicable to a lot of different scenarios. Irrational is now hard at work on BioShock, SS2's 'spiritual successor'.
It's an immensely satisfying format, because players feels as though their choices matter. This game is the prime example of what Levine calls 'emergent gameplay' - very little is pre-scripted, most parts of the game can play out in any order, and players are free to come up with their own strategies for dealing with enemies and obstacles. Ken Levine, president of Irrational Games, has been working to meet the needs of gamers since 1999, when it released System Shock 2.