For all else different in the 1984 Dune movie, I loved the introduction from Princess Irulan. Specifically, I loved the quote, "A beginning is a very delicate time." That quote states a truism, as the beginning is the time when a think is not set, and is most prone to go in a different manner than you intended. It is the same with an RPG campaign, especially when you're the GM. How do you frame the entry into your world for your players, to get the correct feel across to them? It doesn't matter if you're making things up as you go along, or if you've spent a lot of time building your world, as a GM, you have a certain intention when starting a campaign, and it is for that reason that I think you have to set up your intentions in your players' minds even before they take their first actions in your world.
I think about this because I'm currently working on a world for Fate Core, and thinking back on my other experiences as a GM, and how I might have made the transition easier. I'm working through the world building process, and wondering how best to present it not just to my players, but in the material in case I use it elsewhere. Many products produce a quick start or a primer to the world- and I'm thinking that's the way that I will approach it, answering burning questions that will set the stage for the players.
1. What is unique about this world? 2. Why is the world the way it is? 3. What does it feel like to experience this world? 4. What are the recurring themes of the world?
Once I answer these questions, I will go into the specifics of the world, but I think if I answer those questions correctly, it should set the stage, and I can add some more specific factoids to the primer document to give the players some idea of what to expect as they start playing their characters.