FreeCol

A turn-based strategy video game set around several different historic civilizations.

Master of Tactics is a 4X Turn Based Strategy Game. It is non commercial and free to play with no in game sales. It is heavy on strategy and light on micro management. Features include: - Random Galaxy Generation - Custom Craft Design - Tactical Battle System - Diplomacy (Espionage, Sabotage, Trading) - Strategic Resources - Deep Technology Tree

C-evo is a free turn-based strategy computer game whose source code is in the public domain by German developer Steffen Gerlach, its programmer and designer, making the game freeware.

Empire is a 4X wargame created in 1972 by Peter Langston, taking its name from a Reed College board game of the same name. It was initially created by Langston in BASIC on an HP2000 minicomputer at Evergreen State College. When the host computer was retired, the source code to the game was lost. Subsequently, two other authors each independently wrote a new version of the game, both named Empire. In the decades since, numerous other versions of Empire have been developed for a wide variety of platforms. The game is turn-based, with players giving orders at their convenience, and in some versions then executed simultaneously by the game server at set intervals ranging from a few hours to once per day. The game world consists of "sectors", which may be designated as agricultural, industrial, etc. There are dozens of unit types requiring a variety of raw and manufactured materials for their creation. "Blitz" games may last a few hours, typical games a few months, and some larger games up to a year.

Galactic Civilizations II (GalCiv II) is a 4X Grand strategy game set in the 23rd century, when multiple alien civilizations scramble to conquer the galaxy, planet by planet, by force, diplomacy, influence (culture), or technology. GalCiv II focuses on the single player experience that consists of a Campaign mode and a "Sandbox" mode, and omits multi-player. The game is notable for its artificial intelligence, which is challenging without being given resources and abilities not available to the player, as is common in the majority of strategy games.

Songs of Silence is an Art Nouveau-inspired fantasy strategy game with a unique mix of turn-based kingdom management, hero development and real-time combat.

An old forgotten game from your youth. You can't find the manual.

Age of Wonders: Planetfall is the new strategy game from Triumph Studios, creators of the critically acclaimed Age of Wonders and Overlord series, bringing all the exciting tactical-turn based combat and in-depth 4X empire building of its predecessors to space in an all-new sci-fi setting. Emerge from the cosmic dark age of a fallen galactic empire to craft a new future for your people. Explore the planetary ruins and encounter other surviving factions that have each evolved in their own way, as you unravel the history of a shattered civilization. Fight, build, negotiate and technologically advance your way to utopia, in a deep single player campaign, on random maps and against friends in multiplayer.

Build a vast interstellar empire in 30 minutes flat.

Being one of the first, if not the first, 4X game you conquer your way through the galaxy.