To convert to Reformed, you will have to wait until the faith is enabled, which will happen somewhere around two decades after Protestantism appears. After that, it’s as simple as going into the religion tab and manually converting your religion from there!
Reformed Mechanics
Reformed provides a +1 Possible Advisors and a +2 Tolerance of Heretics. You accumulate fervor monthly that you can then spend by enabling one of three focuses:
Trade, providing +10% Global Trade Power and +10% Trade Efficiency War, providing +10% Morale of Armies and +10% Morale of Navies Stability, providing -2% National Unrest and +1 Diplomatic Reputation
Each focus costs 5 fervor per month. The religion’s flexibility and simplicity make it a nice choice. Usually, you maintain one focus active permanently and choose an extra one when you find yourself with high fervor. You can freely change between them anytime – and at no cost.
Converting to Reformed
First of all, you need to wait for the faith to be enabled. Along with Protestantism and Anglicanism, the Reformed faith is enabled later in the game. Here’s the step-by-step process for Reformed to be unlocked: First, Protestantism appears when Catholicism’s reformation desire exceeds 100 points. You can check the reformation desire on the top right corner of the papacy tab if you are a Catholic nation. After Protestantism is enabled and at least 15 years have passed, the Calvinist reformation event has a chance to happen in any Catholic or Protestant country with its Capital in Europe that isn’t the Defender of the Faith. The event has a MTTH mean time to happen of 80 months, meaning it will usually happen in less than two decades after Protestantism makes its appearance. All Christian nations will be notified when this happens. After this event, converting to the Reformed faith is as simple as this: If you are one of the three first nations to champion the faith, you are further rewarded with a Reformed “Center of Reformation” in your lands. These “Centers of Reformation” are very hard to convert even if they fall to enemy hands, and passively spread the faith to nearby provinces. Upon converting, you will get a massive bonus to Missionary Strength vs Heretics, allowing you to rapidly convert your country to the new faith.
Alternate Method: Rebel Conversion
You can always convert by rebels, as with most religions. This is not recommended since you get the option to avoid the entire hassle by simply manually converting through the religion tab. But in case you want to convert as a very large nation, it might be a good idea to allow religious rebels to rise and convert some land to the Reformed faith. This is highly dependent on the Reformation’s initial spawn point and your location. It might still be preferable to convert as soon as possible and ensure you get a Center of Reformation inside your lands. It will significantly help with province conversion.
