Microsoft's "Age of Empires II" is a real-time strategy game for the computer in which you control the progression of your own civilisation. Every time you create a unit in the game, whether it be a soldier or a common field worker, it will take up some of your empire's population limit. The default population limit is 200, but you can enter a cheat code to make it unlimited.

Load or start a new game from the "Age of Empires II" main menu.

Press the "Enter" key to bring up the game's chat box.

Type "DX GENERATION" to get unlimited population for your empire.