Stevenson breaks down the rules of reality in world history in order to prepare you for understanding WHY the modern world is the way it is.
Ever play Monopoly? Settlers of Catan? Risk?
World history is all of those games together at once...
How do you win? What does it mean to win?
Who will you trade with? What will you trade? What will you do about those pesky (insert neighbor societies) who are growing their army?