RPGnet thread of relevance
Many RPGs and many groups have an implicit code of “all the PCs should be able to function as a party, usually”. Sometimes, this has to be explicit.
Vampire’s focus on personal storytelling often gets sufficiently personal that some has to be put on hold to focus on the things the coterie members are doing together. There are better places for extensive one-on-one play than surrounded by other players waiting their turn. Believe me, I’ve taken it too far in the past.
And then there’s the decision of whether to keep OOC secrets, or play the dramas out at the table. Each depends on the preferences of the players, and each relies on everybody to play fair. I often find that players will cheerfully throw their PCs into more trouble...)
My GMing style has evolved to accommodate splitting parties, intercutting (often aiming for dramatic cutoff points) and cross-party communications. With modern games I now assume the PCs have phones. However, I’ll also set out ways for the characters to work together to at least some extent.
How serialised or episodic a game is can be a factor as well. The Lord Of The Rings and Mission: Impossible are both about a group of specialists trying to accomplish vital missions, but one keeps the same party for three books while the other trades PCs in and out weekly. Something like this may be decided due to external factors like player availability. The IMF would suit a large society with players popping in and out better than the Fellowship.
And where and when do you start? If the characters are already running from an angry mob when the game starts, it creates a different feeling than if they’re gathering at the inn where adventurers might hire on.