I wrote more about "good/evil" choices a few years ago: http://spectrecollie.com/archives/2007/09/pro-choice

I think that this article and that one are two separate topics. Here, I'm basically just saying "make the rules of your game based in the narrative, instead of some separate abstracted layer (e.g. mana points)". And, I guess, "drive story development directly from the player's actions instead of just at predefined trigger points (e.g. at the end of the level)".

I suppose you could do that whether or not you wanted to base your game around an alignment switch.

My take on that, though, is that I've never seen a game with alignment "choices" that seemed worth the effort at all. I've never played Fable or Black and White past the first hour or so of each, but I got the impression that whether you choose good or evil is purely cosmetic; it doesn't significantly change the game's story. I have played Fable 2, Fable 3, and Knights of the Old Republic and its sequel, and again, I don't feel like choosing to be good or evil did much beyond change the appearance of my character and the reactions I got from townspeople.

Skyrim (and the other Elder Scrolls games I've played) did the best job of letting you really define an alignment for your character, because you have a lot more freedom all throughout the game. KOTOR just let you be "good" or "petty," for example: the story ultimately plays out the same until the very end, but along the way, you can just choose to insult people. Skyrim gives you more freedom, but then it runs into the other problem: the game doesn't really care whether you're good or evil. You can be a total bastard and still save the world just the same as if you'd been a saint. And if the game doesn't care, then why should I?

I'd rather play a game where I feel like I'm actually participating in (and collaborating in) the development of a story instead of just making simple binary choices among shallow alternatives. If developers really want to explore the whole good/evil thing -- which is totally valid, even if it's not what interests me -- then I wish more would go the route LucasArts did with X-Wing and TIE Fighter. Let me play as the good guys or the bad guys, but give me a story with some actual depth to it either way.