The term is a loose acronym of "explore, expand, exploit, and exterminate", coined in 1993 to describe the gameplay of Master of Orion.
4X games usually feature complex simulations of scientific research, economics, diplomacy, and social dynamics.
Unlike computer wargames, they usually have more ways to win than through warfare, and they model the creation and evolution of an empire from its beginning.
Early precursors include the board games Outreach and Stellar Conquest, both published in the 1970s.
[2][1] Because of the genre's focus on mouse-and-keyboard control schemes, most 4X games are available on personal computers, but examples exist on other platforms.