As its name suggests, Earth 2140 takes place in the year 2140 AD. Previous wars have left much of the Earth a nuclear wasteland, forcing most of the world's population into underground bunkers. Tensions rise between the Earth's two major factions, the Eurasian Dynasty (ED) and the United Civilized States (UCS), as both sides vie for the world's steadily dwindling resources. A UCS raid on an ED base is enough to ignite the rivalry into full-scale war as the ED fails in its bid to control Mexico and the UCS counterattacks Scandinavia, Great Britain, France, and the Iberian Peninsula.

Two little known expansion packs were released for this game:
Earth 2140: Mission Pack 1
Earth 2140: Mission Pack 2 - Final Conflict

A package named Earth 2140 XP was released in August 2006 , it included the game, both expansions and was redone to work under Windows XP.