4X: eXplore an unknown world map, typically procedurally generated, and look for good places to settle new cities. eXpand your civilization by settling cities

4X: eXplore an unknown world map, typically procedurally generated, and look for good places to settle new cities. eXpand your civilization by settling cities and building new public works to grow your economy. eXploit your rival civilizations through shrewd diplomacy and trade. eXterminate anyone who refuses to bend the knee, taking their cities for your own and capturing their technology and public works to improve your civilization even further.