4X

A 4X game is a strategy game about building an empire: explore the map, expand across it, exploit its resources and exterminate your rivals. Economy and technology matter as much as war, and there are often peaceful routes to victory. Most are turn-based, but the term covers real-time games too.

Where the name comes from

Alan Emrich coined the name in a preview of Master of Orion in Computer Gaming World, issue 110, September 1993, titled “MicroProse’s Strategic Space Opera Is Rated XXXX!”. The four Xs stood for explore, expand, exploit and exterminate, and the spelling was a pun on the XXX rating of pornography.

Where the edges are

The line between 4X and grand strategy is blurred; grand strategy is usually described as more asymmetrical, with players tied to a historical starting position. Board-game 4X titles show that “exterminate” is not always required, and real-time 4X games show that turns are not either.

Key 4X games

Each game links to its article; the last column links to the source that puts it in the genre.

Related genres: Grand strategy, Real-time strategy, City builder.

At a glance

Parent genre

Strategy

Name coined

September 1993, Alan Emrich, Computer Gaming World

Origin games

Civilization (1991), Master of Orion (1993)

Also called

XXXX (original spelling)

Sources

Checked November 3, 2026.

1. Full text of "Computer Gaming World Issue 110" — Internet Archive
2. 4X — Wikipedia
3. Grand strategy wargame — Wikipedia