Excommunication in EU3 is the act of cutting off a Catholic ruler and country from the Papacy, and can only be performed by a nation in control of the Curia. If you are Catholic, you are at risk of being excommunicated, but also have the opportunity to excommunicate your enemies. Whoever has cardinals under their control has a chance of becoming the Papal Controller. Whoever is the Papal Controller can excommunicate any Catholic ruler who has a 100 or less relation with the Papal States (except the Papal States). If the Papal States no longer exists, any Catholic nation other than the Curia Controller and the Defender of the Faith may be excommunicated.
Excommunication is against the ruler, rather than the country, so if a ruler is part of a Personal Union, all countries in the union are affected. Once the excommunicated ruler dies or is replaced the Excommunication is lifted. Excommunication may also be lifted at any time by the current Papal Controller.
Excommunication confers several penalties.
- Rulers can declare war without the usual stability penalties for attacking within their religious group or without a casus belli.
- If a ruler dies while excommunicated, all unions dissolve at death.
- Lose -2% Prestige yearly.
- Lose 3 Catholic Tolerance.
- Lose 100% Papal Influence yearly.
If you are excommunicated, you may find that you are more likely to be attacked! For this reason, you should consider gifts to the papal state to maintain good relations if you intend to stay Catholic.
In Heir To The Throne and DW, if a Catholic ruler is excommunicated, all other nations gain the "Excommunicated Ruler" Casus Belli against that ruler's nation.
Note: Excommunication is no longer possible after 1650 (this date can be modded).