Alright, there has been a lot of buzz about Fruitful Void here on SG lately, and I think I more-or-less have a handle on it. FV is that area of the game that isn't explicitly laid out in the rules but generates a lot of fun, the common example being that there are no "rules" for morality in Dogs in the Vineyard, and yet the gameplay is about morality, so lots of fun and dramatic moral play happens there. It is, in essence, the "opposite" of the White Wolf approach of making Humanity a central gameplay element by putting HUMANITY as a big 1-10 stat right there on the sheet.
So, how does that interrelate with the Big Three Questions? To recap, in my own words:
1) What is your game about? (Not "what is the setting, but what is the theme/what issues do you want to explore?)
2) What in your game makes it about that? (What design choices have you made to bring that element into play, and what mechanics exist to make that a game about what you want to explore?)
3) What behaviours are rewarded? (What happens at the table to make the players want to explore your theme?)
I get the feeling that if Baker had slavishly followed the B3, then Dogs as we know and love it could not be, because it seem like the goal of the B3 is to take the fruitful void and make void-juice out of it. It might be delicious, but it's not an open, explorable space.
That may not be the case. Firstly, there are rules about morality in Dogs. Just not dice mechanics. The town-building rules are a systemic structure in the game-as-it's-writ that make it about morality. Not character morality, but branch morality. Character morality becomes a byproduct.
Does this make sense?
As a half-considered follow-up, and maybe this is fodder for another thread: does system really matter? or more accurately, does system matter as much as some say it does? Dogs is a great game about moral conflicts, but I have heard it transposed into lots of situations, and that's because the kernel element of morality is not mechanically-driven. If, rather than the big issues of morality, Dogs had been a game about loyalty or hatred, or something else, all you have to change is the town-construction rules, and suddenly, you are playing a different game that is not Dogs, but the rules of which (theoretically) do a job that is just as good. So, I guess what I mean is that if you are building a game around the FV, you can centre the void on whatever you want. All you've done is make a game about SOMETHING and then told players what the something is. But if it can be easily drifted to be about something else, then does system still matter?