The Crusades puts the player in command of armies of western European Crusaders or hordes of eastern infidels, all with deep religious convictions. The player leads the legions in campaigns to Jerusalem and Constantinople, to reclaim the Holy Lands and recover stolen sacred relics.

While The Crusades emulates the traditional RTS model, in an effort to reduce the steep learning curve associated with many games of this genre, the total number of individual unit types has been reduced.