Crusader Kings II - The game is a dynasty simulator
where the player controls a Medieval dynasty from 1066 to 1453. Through the strategic use of war, marriages and assassinations amongst many other things, the player works to achieve success for his or her dynasty. The simulation is open-ended so the definition of 'success' is completely defined by the player. 
. The only in-game objective is to obtain as much prestige points to your dynasty as to surpass the various historically relevant Christian dynasties in a fictional prestige ranking (the three most prestigious ones being the Capetian dynasty
, the Rurikovich
and the von Habsburg
). Game over happens when the player dies and doesn't have an heir from his dynasty to succeed him. The game employs a genetics and education system where children will inherit most traits, culture, religion and skills from their parents and guardian. This adds an additional strategy to marriages where a player will attempt to breed the best individuals to maximise the quality of future offspring.
While a player can choose almost any landed noble to play, there are some which are unplayable without the use of mods, notably: Republics (such as Venice
), Theocracies (most notably The Papacy) and landed Holy Orders/Mercenaries (for example, the Templars
or the Catalan Company
). Pagans are unplayable at the start of the game but you can convert to a Pagan religion and play freely. Muslims aren't playable without the Sword of Islam DLC. It was possible for the player to convert to Islam prior to the 1.06 patch though they had no special features.