Legion is a turn-based single-player wargame. The strategy of battle involves fighting on favorable terrain with enemies weak against the players units. Other concerns are capturing cities that produce food, stone and wood. Upgrading the cities buildings leads to the production of stronger units.

Each unit in Legion has its own strengths and weaknesses, different types of attacks (melee and ranged) and weapon.
Victory screen of an alternative campaign in Elysium Field. Note that the game declares the player a victor when domination is achieved, rather than total conquest

Legion takes place in the historic setting of the Roman expansion, from the conquest of Italy, Britain, Hispania, Gaul and Germania.