They didn't start with a design document. They started with a pretty picture. It's a shot of a hillside, trees, craggy rocks. Perhaps it was taken in Oregon or England's lake district. In any case, players of Skyrim will look at that picture and immediately be transported into the game.
As creative director Todd Howard explains, the photograph represents the "feeling" of Skyrim's world, the taste of it. "You have to define the experience for the player," he says. "It's not enough to draw up a list of features. The game is about being who you want to be and doing what you want to do."