Religion.txt
This is where the different religions and religion groups are defined, for example:
christian = { catholic = { color = { 0.8 0.8 0 } allowed_conversion = { reformed protestant orthodox } stability_cost = 20 colonists = 2 diplomats = 2 missionaries = 1 missionary_placement_chance = 0.3 papacy = yes #can play with papacy stuff.. annex = yes }
Broken down into components, this represents:
Christian = {
The religion group
catholic = {
The religion in the group
color = { 0.8 0.8 0 }
The color the religion is when the religion color map is selected
allowed_conversion = { reformed Protestant orthodox }
The religions you can convert to from this religion
stability_cost = 20 colonists = 2 diplomats = 2 missionaries = 1 missionary_placement_chance = 0.3
Modifiers this religion gets
papacy = yes
A country with this religion can be a papal controller.
annex = yes
Allows this religion to annex a country with multiple provinces all at once.
Notice: AI-controlled countries will not colonize if their religion has this enabled.
Modding Religions
You can, of course, change, add or remove religions or religion groups as you see fit. The names you see in the game are defined in localisation, and you should make the appropriate changes there when changing something here.
Keep in mind that when you use the modded religion in history files, events and so on, you must use exactly the same name as you define here.