Plot: Freeciv is a single- and multiplayer, turn-based strategy game for workstations and personal computers inspired by the proprietary Sid Meier's Civilization series. It is available for most desktop computer operating systems and available in an online browser based version. Wikipedia
Plot: Sid Meier's Civilization VI is a turn-based strategy 4X video game developed by Firaxis Games, published by 2K Games, and distributed by Take-Two Interactive. Wikipedia