I’ve got a theory.
There’s Setting, System, Character, Situation and Color, right? I think that you can start a game as soon as you’ve nailed down three of the five. That means that a game text must provide at least three of the five to be a whole game. But I really don’t think it matters which three.
You can write a game that provides Character, Situation and Color but leaves Setting and System to be set up by the group, if you want. In fact kill puppies for satan is like that.
Or you could write a game like Sorcerer, providing System, Character and Situation and leaving Setting and Color to the group.
Ars Magica provides Setting, Character and Color, with maybe some Situation too, but not much System at all. (Call me on that, I dare you.) All the WoD games are probably about the same, there.
Obviously, the thicker your game the more you can provide.
Hmm. A game the whole geek family can play:
* Trollbabe: Color (disguised as setting), Situation and character.
* Gods and Monsters: Character, Situation and Color. (And more system than Trollbabe at least.)
* FATE: System, Character. Players must add/select one or more of Setting, Situation and Color.
* Nobilis: Setting, Situation and Color (very little of the actual character is apparent in the stats — there’s more even in d20, where at least skill-point selection reveals preferences and interests.)
* Amber: Setting, Situation and Color (ditto Nobilis, except it has even less system)
* D20: System, Character. Add setting, situation, and color (usually as expressed within skills/feats) to taste.
Hmm… thinking of stuff like Hero and Gurps and whatnot, it seems like most of ‘generic’ systems only have two-of-five, with splatbooks or player input to provide one or more of the other elements.