Players take the role of one of the major powers of the period and fight in both Europe and the colonies. The twist to the game is that in each war, players must form into two alliances.
Once allied with a player you cannot fight each other. This means you do not have the backstabbing of Diplomacy to worry about; if you allied, they with you until the end of the war. This means that a player has to think carefully about who they want to fight against and who they want to ally with. Very often you will want to ally with your natural enemy and go to war with the guy who doesn't really want to fight them.
On top of this you have lots of improvement tiles that you buy to shape your empire, plus alliances with minor powers, and the possibility of going into revolution. Even though it is a big empire building game it will scale from 2 to 7 players and has pretty simple rules.