Researching new technology will grant access to new combat units.Some 4X games even allow players to research different unit components.The first 4X computer games were turn-based, but real-time 4X games are not uncommon.Many 4X computer games were published in the mid-1990s, but were later outsold by other types of strategy games.
Hence, writers have tried to show how 4X games are defined by more than just having each of the four Xs.
Neil Patrick Harris is opening up about his decision to come out as gay back in 2006."For me, I fell in love with a dude and started spending all my time with him," the 40-year-old actor said of his partner of nine years, David Burtka, during his recent visit to .
"And therefore, you don't want to be suppressive of that.
Sid Meier's Civilization is an important example from this formative era, and popularized the level of detail that later became a staple of the genre.
In the new millennium, several 4X releases have become critically and commercially successful.