From the introduction:
The game is split into five Eras, which are each defined by the introduction of a revolutionary technology—the Sunlight Era, farming; the Sketch Era, written communication; the Ship Era, ships; the Factory Era, industry; and the Information Era, digital communication—each Era bringing with it the new experiences and difficulties that the nation has to face. Ultimately, however, this is a game about history, and how much it affects a society throughout time, despite how fragile and changeable a concept it is.
User summary:
The game is distributed as a 7-page PDF rules document and five 2-page color PDF print-and-play custom card documents.