What are the modes of gameplay?
There’s the short mode – where you have to conquer 15 provinces and defeat a specified enemy (the Carthaginians if you’re playing as House Scipii, for example), and the long mode, where you have to conquer 50 provinces including Rome (if you’re non-Roman) or, uh, conquer Rome (if you’re Roman – except here you’ll be fighting against the other families, as opposed to against a united Rome if you play with a non-Roman faction). There are also historical battles, some of which allow you to re-enact the battles of Cynoscephalae, and Trebia. Other than that, you can set up your own custom battle in single player mode (if you are too lazy to pick armies you may want to play a Quick Battle, where the armies, weather conditions, and the map is selected randomly by the game) as well as online.
