On October 15, 2013 Stardock announced that the third installment in the Galactic Civilizations series was in production, exclusively for 64-bit PCs. A pre-release version was made available through Steam in March 2014, which allowed customers to play the game while it is still in development. It is the first game in the series to feature multiplayer and hex-based game tiles. The full version of the game was released on May 14, 2015.
Ten years after the war against the Dread Lords, the Drengin Empire and their Yor allies reign supreme. Most of the races which allied against the Dread Lords have been exterminated or subjugated. Earth lies protected, yet isolated, behind its Precursor shield. In 2242, the Terran First Fleet returns from the pocket universe with advanced technology and a determination to liberate Earth. The three missions of the campaign detail the fleet's efforts to liberate Arcea, deal with the Thalan, and finally dismantle the Drengin presence in the Sol system before bringing down the Precursor shield. The lifting of the shield allows the massively rebuilt Terran Alliance fleet into the galaxy, thus potentially beginning the "Crusade" the Thalan had previously warned about.
Galactic Civilizations III received generally positive reviews from critics. Aggregating review websites GameRankings and MetaCritic gave the game 85.65% and 85/100. Richard Cobbet for PC Gamer said that the game was "easily the best recent 4X of this scale".