Not because I don't find that gaming mechanics do NOT have an effect on the campaign, but because unless the world building aspect is heavily reliant on the magic or alignment system, I find that most instances the game system can have minimal impact on setting design.
Other opinions?
Note, I'm not asking about 3.5 versus 4 here, just the overall impact that the game system has to have on world building.
Personally, I feel that game mechanics usually
do not have a lot to do with world building. IMO, most world information (setting) is predominantly fluff anyways, and therefore independent of mechanics.
However, as far as mechanics do affect world building...I actually feel 3.5
is not particularly good at it (even though it is my chosen system). There are so many default D&D conceits built into the rules, that it can be very hard at times for 3.5 to model something different than a typical D&D world. Strip those conceits from the mechanics, and I feel that 3.5 can very easily and accurately model any world you could possibly imagine, simply by adding on the conceits that you want for the world you want. However, stripping those built in conceits can be quite involved and time consuming (depending on how different from standard D&D your desired world is). Now, if all you want is a standard D&D world with just a few differences...yeah, that's pretty easy.
Frankly, I don't think any edition of D&D is particularly good for world building. Of course, this doesn't mean that you can't world build with D&D, as proven by the decades of homebrewing with D&D. But, unless you want the standard D&D conceits in your world (in which case it's just a matter of creating your fluff), you may have a lot of work to do.
If one was looking for a mechanical system strictly for flexibility in world building, I'd think a more universal system (like maybe Gurps) would work better.
