Fallout 3 and Far Cry 2 are illuminating comparison cases. They are AAA games, came out within a week of each other, and are large open-world games where the player has a high degree of ownership. They have very different play styles (one a run-then-gun shooter, the other an action-RPG with the needle pointing towards RPG), and, most interesting from my perspective, very different authoring styles.
Bethesda is one of the few companies left that creates a wholly authored game world. Every item is placed; every NPC has a script; every quest has been thought out in advance. There are definite upsides to this approach — predictability in testing, being able to create complex interlocking quest systems, and imbuing the world with a level of intricate detail that players don’t see anywhere else. The downsides of this approach are (a) because the systems can get so intricate, they sometimes break in weird ways (oh, wait, because I killed that guy before I started the quest, now I can never finish it), and (b) the authoring effort scales linearly (if you want twice as much content, you need twice as much time or twice as many designers).
The Far Cry 2 team at Ubisoft, though, took a more systemic approach. They created a set of simple, robust systems and let the low-level story emerge from there. They place a thin veneer of high-level narrative to give the player some direction, and then let the game systems play themselves out. This takes a different breed of designer (thinking systemically rather than strictly experientially), and makes testing difficult since you’re almost never able to totally reproduce a given set of circumstances. Logging and metrics become crucial. The upsides are that the player often feels a stronger sense of ownership in the moment — the feeling of “I thought of something, and it worked” or “I made that happen.” Systemic gameplay also makes it a bit easier to author new content, once you have those robust systems in place.
As a game designer and narrative systems dork, I’m much more interested in the approach of FC2. But at the end of the day, I have a lot more fun (and am more likely to want to play) Fallout 3. I’m not entirely sure what I think about that. It’s probably because FC2 doesn’t really get all the way there, but is an interesting step in the right direction, whereas Fallout 3 is a very polished experience from the older school.