A nation state is a geographical area that can be identified as deriving its political legitimacy from serving as a sovereign nation. A state is a political and geopolitical entity, while a nation is a cultural and ethnic one. The term "nation state" implies that the two coincide, but "nation state" formation can take place at different times in different parts of the world.

NationStates is a multiplayer government simulation browser game. It was created by Max Barry and was publicly released on 13 November 2002, based loosely on his novel Jennifer Government. Barry originally founded the site as an independent vehicle publicizing the book one week before its release. The site continues to promote books written by Barry.