Microsoft and Big Huge Games have announced that they are hard at work developing Throne and Patriots, the upcoming expansion pack to Rise of Nations, the strategy game released earlier this year. The expansion pack will include six more new playable nations to the original game's total of 18, along with more than 20 new units, and new features, like the expansion's new campaigns and its government system. The government system will let each nation in the game determine for itself how it will be governed--a decision that will affect its development over the course of history. The new campaigns will include scenarios based on real-world historical engagements.