FreeCol!

The Battle for Wesnoth is a turn-based tactical strategy game with a high fantasy theme.

Freeciv is an open-source, turn-based strategy game based on Civilization II. Inspired by the history of human civilization, the game commences in prehistory and your mission is to lead your tribe from the stone age to the space age...

Widelands is a free, open source real-time strategy game with singleplayer campaigns and a multiplayer mode. The game was inspired by Settlers II™ (© Bluebyte) but has significantly more variety and depth to it. Still, it is easy to get started through playable tutorials.

Classic turn-based strategy game with two armies fighting against each other. Challenge yourself in campaign against AI or hot-seat battle with a friend. Using easy map editor you can create any imaginable scenario to play and share online for others to discover!Each 32x32 sprite was handcrafted in gorgeous, 32 colour pixel art. Original soundtrack was made on Access Virus C and Korg Electribe. Sound effects were made on real GameBoy hardware. Game is open-source and runs smoothly thanks to Godot Engine. »

C-evo is a freeware empire building game for Windows

Unknown Horizons is a 2D real-time strategy simulation with an emphasis on economy and city building. Expand your small settlement to a strong and wealthy colony, collect taxes and supply your inhabitants with valuable goods. Increase your power with a well balanced economy and with strategic trade and diplomacy.

A board game for the web!

TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game. A wide variety of map scenarios have been developed for TripleA (World War II, Punic Wars, Napoleonic wars, etc.) with a variety of rules, units and many options (such as "low luck" which reduces the number of dice rolled making game depend more on strategy).

Advanced Strategic Command is a free, turn based strategy game. It is designed in the tradition of the Battle Isle series from Bluebyte. ASC can be played both against the AI and against other human players, using hotseat or PlayByMail. It is also used to run the multiplayer universe Project Battle Planets.

Fulfill Your Quest For Global Domination

It is the year 2077, for the first time in its history mankind has finally began the colonization of another planet. Will the pioneers from Earth succeed in colonizing their new home or will they fail to survive against the harsh and inhospitable conditions of the Red planet?

webDiplomacy is a multiplayer, online version of Diplomacy, the popular turn based strategy game in which you battle to control Europe; to win you must be diplomatic and strategic.