All I’m trying to say is that sometimes a game feels like levels and sometimes it fells like a world. Do you know what I mean? The difference is subtle but important. I have fun playing either way—the game play “works” regardless—but the times that I feel I’m in an actual world, as opposed to digitized geometry, are the times I remember most. Those are the experiences that keep me gaming.

 I’ve compiled notes on the conditions that enhance, or at least encourage, the feeling that a game’s environment is a real place, that it may theoretically exist somewhere out there and is not just a collection of levels built solely for my amusement. Surprisingly, this kind of immersion has little to do with graphics (though good graphics never hurt, they are not the focus of this article).

  It has more to do with subtle elements borrowed from the real world. My notes on well-constructed believable game worlds, derived from many, many hours of video games played since I was a tricycle-riding youth, are summarized below into three main points. Strangely enough, all three points relate directly to ecology. Think of this article as an attempt to preach the basic ecology of video game world building.