My group and I work on the assumption that a game system's default assumptions are its manifesto, and that by choosing a system we are choosing to let its assumptions stand except where we institute explicit house rules to the contrary (which we feel free to do as necessary).
I'm talking about fundamental policies like "how easy is it to die?" that define the nature of the game experience. Knowing these policies up front tells the group what they're getting into, and helps avoid terribly hurt feelings later on.
Moving into DFRPG from more structured systems [I know DFRPG is still crunchier than many FATE products, and I'm working on the assumption that's a) intentional on the part of the developers and b) desirable for my group because of our background], I noticed that many assumptions another system would take on itself to set --like how easy it is to die-- are explicitly left as collaborative decisions made by the group in DFRPG.
Two examples that stood out in Your Story are,
This [who decides if a character has broken a Law] is something that a gaming group should decide on as a policy for their specific game. (YS234)
This [character death as a result of being taken out] is something you’re going to want to talk about as a group out-of-game, to see where everyone is on the subject... (YS206)
I love this collaborative philosophy, and the agency it gives the entire group. These sound like foundational, game-defining policy decisions that I wouldn't necessarily have thought of putting explicitly to the group --and in some cases wouldn't have recognized as decisions to be consciously made at all-- because we're used to the system making them for us.
What are the table-level game policy decisions, that will define the experience of the group and determine if it’s the kind of game the group wants to play, the group should consult on before or during city creation? Your Story lists a few (I gave examples above) but they’re sprinkled around; I’m sure I’ve missed some of them, and the SE Voice of Experience probably has ideas too.
(Obviously some rules decisions are better left for the heat of the moment when context is king, but that’s not what I’m asking about. Leaving the choice of who gets to decide if your wizard just turned into an NPC until it’s actually happening? Is a recipe for bad feelings all around. That's why I added the [social-contract] tag and not the [rules] tag.)
If an answer seems like it's turning into a list, then these points might help (otherwise feel free to ignore them if you think they prohibit a good answer):
1) This is tagged [dresden-files] for a reason; I suspect the setting defines the policy issues to a great extent, and I cited the Laws quote as an example of how.
2) Experience is probably key. If you can say what your group has done, how it turned out, and what you'd do differently or the same next time, that'd be most excellent.
Edit to clarify position: I have no problem with the idea of FATE as a game founded on group collaboration, and I love the idea of shedding the "GM mystique"; in fact, both of these ideas excite me unduly. I am trying to identify a specific subset of topics that should be addressed in the appropriate FATE fashion at the beginning of a campaign in a specific setting in order to make sure everyone is on the same page. My question is about learning how to facilitate the FATE philosophy, as someone who has not yet gained the skills and experience to do this organically.