Sid Meier's Civilization is a 1991 turn-based strategy 4X video game developed and published by MicroProse. The game was originally developed for MS-DOS running on a PC, and it has undergone numerous revisions for various platforms. The player is tasked with leading an entire human civilization over the course of several millennia by controlling various areas such as urban development, exploration, government, trade, research, and military. The player can control individual units and advance the exploration, conquest and settlement of the game's world. The player can also make such decisions as setting forms of government, tax rates and research priorities. The player's civilization is in competition with other computer-controlled civilizations, with which the player can enter diplomatic relationships that can either end in alliances or lead to war.

4X is a subgenre of strategy-based computer and board games, and includes both turn-based and real-time strategy titles. The gameplay generally involves building an empire. Emphasis is placed upon economic and technological development, as well as a range of military and non-military routes to supremacy.