Editing Unwritten: System Reference Document/Starting a Game (section)

====Accessibility of the Art====
Explorers have been slowly rediscovering the Art, but how much of that will actually be in the hands of the players?

If the Art is completely inaccessible to the players, then travel to the Ages is entirely dependent on what Books they can find. Getting to a particular Book may be an adventure in itself, whether they are blocked by physical obstacles or unhelpful NPCs. It means that the place in the Age where the Book links to is inherently a key location, since all incoming visitors will end up in the same place. Access to a new Age is a significant event here, and requires discovering a Linking Book. 

On the other end of the scale, if the Art is central to your game and some or all of the characters are Writers, you have significantly different possibilities. The availability of new Ages is defined by the skill, vision, and time of the characters (limited by the availability of appropriate books and ink). Solving a problem by Writing an Age that has what you need is a potential option, with all of the ramifications that come with that. Mistakes may literally have cosmic implications.

A middle ground may be that your characters have the ability to create Linking Books, but not Descriptive Books. In this option, new Ages may not be forthcoming, but travel between existing Ages will be more flexible as characters write Linking Books to new places in existing Ages.