@Quertus: it isn't necessarily intuitive, but a game master making the player characters and their backstory isn't opposed to sandbox play. The reason is simply because control over game set-up isn't the same as being controlling during play. Mr. Baker's freedom to flip off Sir Imperius doesn't go anywhere even if Mr. Baker's premade character sheet reads he's the Hero of Space, Champion of Princess Hilda, wielder of the Rectangle of Bravery.