Religion is "a system of beliefs held to with ardor and faith". It is a central topic of EU2, from the Catholic supremacy of the late middle ages through the Reformation and Counter-reformation. The game models religious strife in Europe and elsewhere in the world (for example Shi'a versus Sunni Moslems), and the Christianization of pagans via colonization and missionary work.
Religions and Religion Groups
There are eleven religions (including paganism) in the game. The religions are: Catholicism, Counterreform Catholic, Protestant, Reformed, Orthodox, Confucianism, Hinduism, Buddhism, Shi'a Moslem, Sunni Moslem, and paganism.
There are a few rules where a set of religions acts similarly, and so it is convenient to be able to talk about religion groups. "Islam" comprises all Moslems: Shi'ite and Sunni. "Western Christian" comprises Catholicism and the religions that schismed from it: Catholic, Counterreform Catholic, Protestant, and Reformed. "Christian" comprises all Western Christians plus Orthodox.
Domains of Religion
All settlements (colonies and cities) also have a religion. You can see their religion on the province screen. Their religion may or may not match the state religion of their owning country; when it doesn't, certain penalties apply. A country may attempt religious conversion of cities which are not of the state religion. There are a few effects of religion based not on state religion but the religion of settlements.
Every unsettled land province has a "base" religion. If the province has a trading post you can see it on the province screen. This religion is fixed by the scenario and cannot change. Its only effect is to make initial colonization a bit more difficult; see below.
Penalties for Religious Diversity
Religion has a number of effects. When a country owns a settlement that does not match its state religion, the settlement:
- has a -30% on province tax income.
- has reduced recruitment potential (number of armies you can build there). This is actually a side effect of the province tax income reduction.
- has amplified revolt risk from war exhaustion.
- is harder and costlier to colonize. The modifier is +8% for colonizing a settlement or province with your state religion. (When colonizing empty provinces, the provincial base religion is used; otherwise the settlement's religion.)
- can get "heretics" random events, which cause rebellions in randomly-chosen settlements that are not of the state religion.