4X games are a genre of strategy video game where players control an empire and "eXplore, eXpand, eXploit, and eXterminate." This term was first used by Alan Emrich in his September 1993 preview of Master of Orion for Computer Gaming World. Since 1993, other game commentators have adopted "4X" to describe any game with similar design. 4X games are noted for their deep, complex gameplay. These games emphasize economic and technological development, as well as a range of non-military routes to supremacy. Managing the details of a large empire can cause 4X games to take longer to complete than other strategy games. Since the amount of micromanagement required to sustain an empire scales as the empire grows, 4X games are sometimes criticized for becoming tedious near the end of the game. As a result, several games have attempted to address these criticisms by reducing micromanagement. The earliest 4X games borrowed ideas from board games and 1970s text-based computer games. The first 4X games were turn-based, but real-time 4X games have been released. Many 4X games were published in the mid-1990s, but they were outsold by other strategy games by the late 1990s. In the new millennium, several 4X releases have been critically and commercially successful. One well-known 4X game is Sid Meier's Civilization from 1990, which popularized the level of detail that has become a staple of the genre. (via Wikipedia)