This manuscript will repeatedly stress the limits of knowledge in a medieval world. You, good sir, who read this manuscript, have access to an extraordinary amount of information. There is the internet and cell phones, there is television and radio, there are printed books, and there are libraries and universities and experts in your world.
In a medieval setting, none of this exists. Pens and paper are expensive, there are no printing presses, and it takes a scribe almost a year to manufacture a single book. Most people are illiterate; there is no mechanized transportation, no long-range communication, and no photography. Information is communicated at the speed of verbal conversation, without photograph or illustration, and that information moves only so fast as a traveler’s feet or his horse and wagon. The traveler is the primary source of information in this world. With travel comes knowledge; without travel there is no information.
Most everyday peasants in a medieval setting never travel more than a few miles from their places of birth. Their lives are circumscribed by local terrain boundaries: a river to the east, the hills to the north, the village one town over to the south. In a game that accurately attempts to capture the medieval adventuring experience—or, phrased differently, in a game that retains the spirit of Appendix N—you do not need a vast space for adventuring. An area of land only 100 miles square should provide years of adventure, for it is a space larger than most living men will ever explore.