Crusader Kings also differs from many similar turn-based strategy games in that time flows continuously rather than taking place in discrete turns. In addition, yearly random events, as well as hundreds of pre-scripted ones based on the historical themes, make for varied game play and challenges. Rulers are supported by appointed councillors, a Chancellor, Steward, Marshal, Spy Master, and Diocese Bishop, and oversee scutage from their vassals.

In the game, the player attempts to lead their dynastic demesne across four centuries, while managing its familial, economic, military, political, and religious affairs and stability. Unlike other Paradox titles (such as the first two Europa Universalis series), Crusader Kings is a dynasty simulator with similarities to role-playing video games in that it focuses on a trait-based individual whose primary goal is the growth and enrichment of their dynasty. Three scenarios are also included in the game, namely: the Battle of Hastings (1066), the Third Crusade (1187), and the Hundred Years' War (started in 1337). The game is set primarily in Europe in the mid to late Middle Ages in the time-period from Decem(the day after the coronation of William the Conqueror) until Decem(five months before the fall of Constantinople).

Crusader kings 2 crusades