In the earlier start dates of CK2+, the Schism hasn't occured yet, and Catholicism and Orthodoxy are still united as Chalcedonian Christianity. However, as the game goes on, events will fire that will eventually lead to the Schism. The farther along the game is, and the more events that have fired, the more likely it is that the Schism will occur, with the earliest possible date being 950. The rate at which the events fire is influenced by Chalcedonian Moral Authority, with high Authority slowing the event rate and low Authority speeding it up.
The Schism can be prevented entirely by creating a Chalcedonian religious head, known as the Patriarch Supreme. In order to do this, the following conditions must be met:
-An appropriate Patriarch exists (Patriarch of Constantinople following Greek Rites, or Pope following Latin Rites)
-An independent ruler can back either Patriarch (Greek rulers and the Basileus can only back the Patriarch of Constantinople, while Italian and Lombard rulers, the Karling Emperor, and the Kaiser can only back the Pope, and all others can choose either). For an independent ruler to be able to back either Patriarch, they must meet the following conditions:
>is either the Patriarch in question, or is an Emperor with at least 1,500 Prestige and either:
---has the Patriarch in question vassalized
---has a religious head that follows the same rites as the Patriarch in question
>has at least 1,500 piety
>is not at war
>does not have a regency
>has neither the Wicked Priest trait nor the Excommunicated trait
-One of the following must be true:
>The opposing Patriarch doesn't exist
>The opposing Patriarch follows the same rites as the supported Patriarch
>At least two other Patriarchs follow the same rites as the supported Patriarch
If all these conditions are met, then a Patriarch Supreme can be named via decision, which will stop the Schism from happening. The AI can and will make this decision if the requirements are met and an eligable AI ruler arises.