Quasqueton said:
Why does a published setting need "support"? And what is "support," anyway?
IMHO, support is more stuff from the people that own the setting. Whether the original creator is still doing all the creating, only partially involved, or has completely sold (or been robbed of) his/her rights, whoever it is that's pumping out more stuff.
Hopefully, those involved are people who actually like the setting, who "get" it, and who are doing it because they enjoy doing it, and not just to sell more stuff. Also, they are hopefully doing a better job than the average Joe DM could keeping track of continuity, minor and not-so-minor NPCs, plotlines, world-shattering events, etc.
For the publisher: settings need support so they have more stuff to sell you.
For the DM: Because the more work the publisher does, the less I have to do, and my time is always at a premium.
For the player: Because "official" stuff is more likely to be accepted by my DM.
For the auteur: Because all this stuff is in my head, and I
need to get it out!
Quasqueton said:
How big does a setting need to be? A full world? A continent? A single kingdom? A single city?
It needs to be as big as it needs to be. It could be a single building (Hogwarts, in a Harry Potter game), a galaxy (SW, ST, B5), or multiple dimensions/planes (Planescape, Infinite Worlds, Torg). It needs to be big enough to contain the stories and characters you envision in it.
That being said, you do need a certain amount of detail for a setting to actually be useful to a new reader. "The galaxy is full of planets, some industrialized, some feral, some toxic." is not enough.
Quasqueton said:
Does a setting need new rules---classes, feats, spells, and such? Would a detailed description (fluff) be enough for a setting?
For me, it could be enough(if I really liked the ideas in the setting). For some, it couldn't. It's certainly
nice to have the additional crunch, and I think it's certainly the common expectation. I do think that a new setting book without any crunch would be a hard sell at this point. But I have books like GURPS Warehouse 23, Suppressed Transmission (1 & 2), and the Atlas of Middle-Earth, all of which have little to no crunch, and all of which I consider great gaming books.