Last summer sometime Ninja J and I spent a whole afternoon walking all the heck over Northampton. Among many other things, we talked about a beloved old game he'd GMed; particularly, we talked about how rich and alive its setting was, how detailed. His players ate it up, he said, they'd go on and on about how compelling, complete, fully realized the setting was.
Then he told me how he'd done it. He'd taken three principles - I wish I could remember them in particular, J please step in here, but they were like "nobody thinks that they themselves are evil," "the Grand Galactic Empire is procedurally conservative," and "nobody really enjoys their job" - three principles something like those, and whenever any of his players asked him about anything in the setting, he'd simply apply those principles to create the answer.
Now that is a cool tip. it basically fits the idea that Ron Edwards pushes for Setting, which is to take a leaf from the dramatic writing how-to's and determine your game's premise - i.e. the philosophical idea it is wrestling with.
The punchline is: most RPGs' setting material (along with all primary source fiction, like Firefly or The Lord of the Rings) is the end product of a creative process. What do we roleplayers need? We need the starting point of the creative process instead.
Later in the comments Ninja J steps in to clarify his rules, and adds:
It's how I've run games ever since. Characters have motivations and anytime the protags do something, I ask myself what the NPCs would do in this situation, given their resources. Sometimes it's simple: "Queen Elizabeth's agents will never betray her because she's got something on them." "Jean-Renard is a coward and will funnel his resources into violence only as long as it will keep him out of danger." Along those lines.
I've found that you wind up with NPCs that seem really real because they're not prescripted. You have a world that seems real because, even when you don't know what's under every rock, you know the kind of thing that should be there.
Sydney summarizes with:
I'm really wondering now if the Technique we're trying to isolate from various specific instances actually involves combining
(1) seed crystals: highly specific, concrete, vividly visual images -- but with plenty of complexity and ambiguity to stimulate and allow growth in multiple directions [Angus: Characters, Ideas, Gadgets, Locations, Organisations]
(2) generation rules: simple, clear, abstract principles that guide how new specifics are derived from existing specifics.
This gives me some things to think about, I'm not sure what these should be for my own game, but I'm sure thinking about them will be more fruitful than working out yet another set of NPCs (and maps, and plot points, and ... etc) that my players never go anywhere near!