Recently found something of interest over on the Wizards forums: Session Zero.
The thread itself never really took off, but:
(1) There are some good links to be followed.
(2) The specific term “session zero” strikes me as a useful one.
Exactly what the session zero for a given campaign will look like — and the things it’s trying to achieve — is likely to be quite variable. But the basic idea that there’s usually work to be done before “go time” in the campaign is a valuable one which frequently gets overlooked.
I definitely have Session Zeros when I start new campaigns and new games. There is also a pre-zero session – a bunch of one on one interactions with the individual players, where I first tell them about a game world and they create their character and it gets written into the setting. Session Zero occurs when the players meet for the first time. Each introduces their character and I tell them more about where they are and about their starting place. Players then flesh out their equipment, recruit NPC who would join them, do their research and organize the expedition. All encounters role-played. Next session the actual adventure starts with the overland travel.