Real time strategy (RTS) games require the player's consideration and foresight as well as quick adaption to new situations. For linux, Glest is such a game which is also freely available. 

This game is situated in an ancient world, where technological and magic factions compete with each other. The player can take part in the game as either party and play against up to three opponents. Selection of terrains and tilesets and the grouping of different teams enable you to set up a variety of scenarios. As known from other RTS games, you start at a home site with a few basic units. They are used to gather your first resources (harvest lumber, mine ore) or create new buildings. Also a few combat units are initially provided, to defend the village or scout the surroundings. While proceeding, an increasing number of different units become available and new types of buildings can be constructed. The challenge of this game is to have eye on your resources, to defend your base against opponent encroachments and build up a force to defeat your enemies at the same time. Therefore, different types of ground units and air units are there for your use. Featuring advanced graphics, skillfully designed units and lavish terrains, glest does not need to hide from commercial games. Glest offers single player only so far, while multiplayer support is planned and will be added as soon as possible.

Game source and data can freely be downloaded from the project pages (www.glest.org) also you can find a ready to install binary version of glest at the loki installers for linux gamers site (liflg.org).