"Play in medieval settings to lead"
Battle for Wesnoth is a war strategy game set in the Middle Ages. This program is written in open source and is also multiplatform (for Windows, Mac and Linux) thing that happens rarely in computer games. Open source allows other developers or the players themselves to implement it according to their knowledge or needs.
In Battle for Wesnoth you can play in a medieval setting where problems abound and you must lead your troops and keep the situation under control. You will use medieval weapons and other tricks typical of the time such as potions and spells.