Religion modding - Europa Universalis 4 Wiki (2024)

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This article is a guide to adding new and editing existing religions and religion groups. It assumes familiarity with the game mechanics surrounding religion.


  • 1 Quick checklist
  • 2 The religion file
    • 2.1 Religion group
    • 2.2 Custom and client nation flags
    • 2.3 Religion entry
      • 2.3.1 Modifiers
      • 2.3.2 Religious conversion
      • 2.3.3 Religion mechanics
      • 2.3.4 Other religion attributes
      • 2.3.5 Modability of mechanics
  • 3 Religion graphics and interface
    • 3.1 Icon graphics
    • 3.2 Icon interface
    • 3.3 Religion interface window
  • 4 Localisation
  • 5 Personal deity modding
    • 5.1 Personal deities file
    • 5.2 Personal deity icons
    • 5.3 Personal deity localisation
  • 6 Church Aspects modding
    • 6.1 Church Aspects file
    • 6.2 Church Aspects GUI
    • 6.3 Church Aspects localisation
  • 7 Centre of Reformation modding
    • 7.1 Centre of Reformation localisation
  • 8 Sound effects
  • 9 Vanilla religion names

Quick checklist[edit | edit source]

To add a new religion:

  • Create an entry for the religion (and a religion group, if necessary) in a religion file
  • Add icons to the icon_religion, icon_religion_small, and province_view_religion files in the gfx/interface folder
  • Add frames to the corresponding entries in interface/countryview.GFX, interface/provinceview.GFX, and interface/countrycourtview.GUI
  • Add localisation for the new religion
  • Confucian modifiers are distributed across religion.txt, defines.lua, and event modifiers

The religion file[edit | edit source]

Vanilla religions are found in common/religions/00_religions.txt. To edit these religions or to add new religions to vanilla religion groups, copy this file to a mod and edit it there. Do not change the name of the file. To add entirely new religion groups, instead create a new .txt file with any name in a mod's common/religions folder. A simple religious group with a single entry looks like this:

jewish_group = { flags_with_emblem_percentage = 33 flag_emblem_index_range = { 28 28 } jewish = { icon = 20 color = { 0.6 0.1 0.4 } country = { tolerance_own = 2 advisor_pool = 1 } province = { local_missionary_strength = -0.02 } heretic = { SAMARITAN KARAITE } }}

Religion group[edit | edit source]

All religions must be within religion groups (Christian, Jewish, Muslim, etc). Religion groups must have a unique name. In this section, before the addition of religions to a group, can be attributes shared by all religions in the group. All of these attributes are optional. The most notable are:

defender_of_faith = yesDetermines whether countries with a religion in the group can use the defender of the faith mechanic.
can_form_personal_unions = yesDetermines whether countries with a religion in the group can use the personal unions mechanic
center_of_religion = [province id]Determines the most important province for this religion group. Centers of Reformation can only appear on the same continent as the Center of Religion.
crusade_name = CRUSADEDetermines the name of a holy war declared in the name of this religion group using certain CB's.

Custom and client nation flags[edit | edit source]

It is also possible to determine the variety of flags that will be generated for non-player-created custom nations and client states. This can be determined at the religion group level (as it always is in vanilla), but can be overridden in the individual religion entries within the group.

flags_with_emblem_percentage = 33flag_emblem_index_range = { 1 18 }

The first attribute determines how likely a generated flag is to contain an emblem. It is a simple percentage rate.The second attribute determines the range of emblems that can be generated. This is to ensure that entirely inappropriate flags are not generated for new countries, e.g. a Muslim nation with a crucifix emblem.

Religion entry[edit | edit source]

New religions must have a unique name. Religion entries must contain at least the following:

  • color = { 0 127 255 } - A color (used for the religion map mode), using 8-bit RGB (0-255) format since Patch 1.21; using decimal (0.0-1.0) in all versions before Patch 1.21.
  • icon = 20 - An integer representing the icon for the religion in the interface files. This will be further explained later.
  • heretic = { SAMARITAN KARAITE } - The name/s of heretic rebel types for the religion. There should be at least one heretic type listed.

Modifiers[edit | edit source]

Country-scope modifiers are applied to a country that is a specific religion. The country scope within the religion scope defines these modifiers:

country = { tolerance_own = 2 advisor_pool = 1}

Province-scope modifiers are applied to provinces that are a specific religion. The province scope within the religion scope defines these modifiers:

province = { local_missionary_strength = -0.02}

For syncretic faiths, different country-scope modifiers are applied to a country that adopts a specific religion via syncretic faith. The country_as_secondary scope within the religion scope defines these modifiers:

country_as_secondary = { idea_cost = -0.1}

Religious conversion[edit | edit source]

Some religions can choose, under certain circ*mstances, to convert to other religions. To allow a religion to convert to another religion, add the following to the religion entry:

allowed_conversion = { hinduism}

If religious conversion is allowed, an "on_convert" section should also be included, such as the following:

on_convert = { change_religion = hinduism add_prestige = -100 add_country_modifier = { name = "conversion_zeal" duration = 3650 }}

At the very least, this section should contain the "change_religion = [target religion]" line. This section can include any standard effects that scope to a country.

Religion mechanics[edit | edit source]

A new religion can use the special mechanics of vanilla religions if specified. It is recommended that you do not mix and match mechanics from different vanilla religions. It is possible to do so, but may require advanced interface modding to work correctly. Mechanics include:

papacy = {}Uses the Catholic Papacy system. Is not Boolean; must define Papal tag, election cost, and seat of papacy within papacy entry.
hre_religion = yesUses the HRE religious factions and thirty years war systems. A religion with this attribute will be the default official religion of the HRE, as Catholicism is in the vanilla game.
hre_heretic_religion = yesAs above, but determines the religion that will be considered the primary heresy, as Protestantism is in the vanilla game.
date = [any date]Determines the date that this religion becomes active in the game's history (will have no effect on games started before this date).
fervor = yesUses the Reformed fervor mechanic
fetishist_cult = yesUses the fetishist cult mechanic (used both by Fetishist and Alcheringa in the basegame)
has_patriarchs = yesUses the Orthodox patriarch authority mechanic
uses_piety = yesUses the Muslim piety mechanic
personal_deity = yesUses the personal deity system (used by Norse and Hinduism in vanilla)
authority = yesUses the Inti authority mechanic
religious_reforms = yesUses the Mesoamerican religious reform mechanic
doom = yesUses the Nahuatl doom mechanic
uses_church_power = yesUses church power mechanics
uses_anglican_power = yesUses Anglican aspect mechanics
uses_karma = yesUses the Buddhist Karma mechanic
uses_isolationism = yesUses the Shinto isolationism mechanics. Disasters must be defined separately.
ancestors = yesUses the Totemist ancestors mechanic
gurus = {}Uses the Sikh gurus mechanic. Is not Boolean; must define gurus separately within guru entry.

Other religion attributes[edit | edit source]

There are some other special attributes that can be used, but which do not involve the complications associated with religious mechanics:

misguided_heretic = yesOther religions in the group will have a higher default relation with these countries than they would with other heretic countries. In the vanilla game, Coptic and Orthodox have this bonus.
declare_war_in_regency = yesCountries with this religion can declare war during regencies. In the vanilla game, only Nahuatl has this bonus.
can_have_secondary_religion = yesCountries with this religion can have a syncretic faith, like the Tengri religion in the vanilla game. Unlike other religious mechanics, religions with this mechanic can also utilize one other religious mechanic without problem.

Modability of mechanics[edit | edit source]

An overview of what mechanics work for a new custom religion.

Catholic papacyCan only be changed globally. Can change Papal Actions, Golden Bulls, Papal screen is mostly hard-coded but localization and appearance is moddable. Papal tags are unique to each religion, and without one the papacy mechanic will not function.
Reformed fervorCan only be changed globally. Can change gain modifier of fervor. Can change effect and cost of fervor focus.
Orthodox patriarchsIcons can be changed and are well moddable. Patriarch authority can only be changed globally.
Muslim pietyCan only be changed globally. Change scaled modifiers for high and low piety, and can change piety actions.
Norse/Hinduism personal_deityWell moddable, can add new deities for a custom religion.
Inti authorityFairly well moddable. To make religious reforms work for a new religion, add an event in on_buy_religious_reform within 00_on_actions.txt in common/on_actions.
Mesoamerican religious reformsSee Inti authority.
Nahuatl doomDoom mechanics can only be changed globally, and only works before reforming the faith, but is otherwise moddable. See Inti authority.
Protestant aspectsWell moddable, introducing new aspects and changing costs and support for trigger and potential.
Anglican aspectsWell moddable, introducing new aspects, changing costs and support for trigger and potential
Coptic holy sitesWell moddable, adding new holy site locations and effects. Does not require a specific entry for countryreligionview.gui unlike Protestant or Anglican aspects.
Buddhist karmaCan only be changed globally. Effects of actions changable. Modifier of low/high karma changeable.
Shinto isolationismFairly well moddable. Isolationism level can only be changed globally and is defined for every country using this mechanic. Unique incidents can be added for custom religions .
Sikh gurusWell moddable, adding guru effects, aspects, dates, and names unique for each religion. The Guru teaching modifier can only be changed globally.
HarmonyLimited. Specific modifiers for a single religion can be added but only to heretical religions. While anyone outside that (Heathens) will be forced under a single religion group respective to them (Christian, Muslim, Dharmic etc).

Religion graphics and interface[edit | edit source]

New religions should have their own graphics and icons, and they may fail without an interface.

Icon graphics[edit | edit source]

Find the following files in the gfx/interface folder and copy them to a mod:

  • seen in diplomacy view.
  • seen in religion tab.
  • seen in province view.
  • seen on CoR on the map.

Edit these files with your preferred graphics editing software. Expand the image horizontally and add your new icon.

Hint: The file for and are equivalent.

Icon interface[edit | edit source]

Find the following files in the interface folder and copy them to a mod:

  • countryview.gfx
  • ledger.gfx
  • provinceview.gfx

In countryview.gfx, find the sprites with the names "GFX_icon_religion", "GFX_country_icon_religion" and "GFX_icon_religion_small". In these entries, find the line with the number of frames. Add to this number the number of new religion icons you added to the religion strip in the above stage. In provinceview.gfx, do the same for the sprite named "GFX_province_view_religion". In ledger.gfx, do the same for the sprite named "GFX_religion_icon_strip".

Religion interface window[edit | edit source]

If you're attempting to make a mod-added religion work with the Protestant or Anglican aspects screen, you'll have to go into interface/countryreligionview.gui and add a church aspect item window named countryreligionview_aspectitem_YOURRELIGION (Protestant example shown):

windowType = {name = "countryreligionview_aspectitem_protestant"backGround =""position = { x=10 y=-20 }size = { x=50 y=46 }moveable = 0dontRender = ""horizontalBorder = ""Orientation = "UPPER_LEFT"iconType ={name ="aspect_icon"spriteType = "GFX_hindu_deities_strip"position = { x= 45 y = -14 }}instantTextBoxType = {name = "aspect_name"position = { x= -42 y = 6 }font = "vic_18"borderSize = {x = 0 y = 0}text = "AspectName"maxWidth = 102maxHeight = 108Orientation = "UPPER_LEFT"format = left}instantTextBoxType = {name = "aspect_effect"position = { x = 98 y = -2 }font = "vic_18"borderSize = {x = 0 y = 0}text = "AspectEffect"maxWidth = 206maxHeight = 108Orientation = "UPPER_LEFT"format = left}guiButtonType = {name = "pick_aspect"position = { x=301 y = 1}quadTextureSprite ="GFX_standard_button_71"buttonText = "SELECT"buttonFont = "vic_18"Orientation = "LEFT"}}

You don't have actually have to copy and edit the vanilla gui file for that, a new file works as well.Without it, the game may crash upon clicking the button to select an aspect.

Localisation[edit | edit source]

There are a variety of items that need to be localised once a religion has been added. These are the localisation entries for the Jewish religion group, as an example:

jewish_group: "Jewish"jewish: "Jewish"jewish_religion_desc:1 "The oldest Abrahamic religion in the game, Judaism builds upon the Torah and the traditions and scriptures of the Jewish people going back over 3000 years.\nBy the start of the game the Jewish faith is a minority faith in most of the world and only exist in the two provinces of Semien and Dembiya in Ethiopia."karaite: "Karaite"samaritan: "Samaritan"jewish_rebels_demand: "Convert $COUNTRYNAME$"jewish_rebels_demand_desc: "The religious rebels fight for the $RELIGION$ religion. They demand that we recognize its supremacy or at the very least cease our efforts to convert them and let them worship in peace."jewish_rebels_title: "Religious"jewish_rebels_name: "$RELIGION$ Zealots"jewish_rebels_desc: "Religious fanatics tend to rise up in provinces controlled by nations of a different faith. They seek to spread their faith and smite all unbelievers."jewish_rebels_army: "$RELIGION$ Army"

Here, the names of the religion and religion group have been localised, as well as the names of heretic types. Localisation has also been added for religious rebels of the Jewish religion.

Personal deity modding[edit | edit source]

A religion uses the personal deities system if the line personal_deity = yes is included in its entry in the religion folder. To edit existing Norse or Hindu deities, copy the relevant file from common/personal_deities to a mod. To create new personal deities, create a new text file in the common/personal_deities folder of a mod.

Personal deities file[edit | edit source]

Here is an example of a custom entry in a personal deities file:

quetzalcoatl = {idea_cost = 0.05land_morale = 0.1sprite = 55potential= { religion = nahuatl }trigger = {}effect = {}removed_effect = {}ai_will_do = { factor = 1 modifier = { factor = 2 personality = ai_militarist } modifier = { factor = 0.5 personality = ai_diplomat }}}

There are 4 sections in this entry:

  • Bonuses: Unsorted attributes at the beginning of the entry. Uses any effect that scopes to a country.
  • sprite: Determines which deity icon will be used. A value higher than the actual number of deities will result in no icon being displayed, which is a valid choice.
  • potential: Uses any trigger that scopes to a country. One trigger should determine the religion the deity is designed for. If the trigger is not fulfilled, the deity is not shown in the list.
  • trigger: Uses any trigger that scopes to a country. If the trigger is not fulfilled, the deity can't be selected and the player can see the trigger in a tooltip.
  • effect: Please add some documentation here
  • removed_effect: Please add some documentation here
  • ai_will_do: Instructions for how AI nations choose personal deities. Uses any trigger that scopes to a country, though in vanilla the only triggers used are ai personality.

Personal deity icons[edit | edit source]

Icons for personal deities are created and referenced in much the same way as icons for religions, though in this case there are files to edit.

The graphics file is found in gfx/interface/ Copy it over to a mod. To add new icons, open the file with your preferred graphics editing software, expand the frame, and add your new icon(s).

The interface file is found in interface/countryreligionview. Copy it over to a mod. Find the sprite named "GFX_hindu_deities_strip" within this file, and add a number of frames equal to the number of new icons you added to the graphics file.

Personal deity localisation[edit | edit source]

Localisation for personal deities is very simple:

shiva: "Shiva"shiva_desc: "Shiva is the god of transformation through destruction and the Lord of Dance."

Church Aspects modding[edit | edit source]

A religion uses the Church Aspects mechanics if uses_church_power = yes is included as a line in its religion entry. Church Aspect files are found in the common/church_aspects path. Vanilla entries can be edited in common/church_aspects/00_church_aspects.txt, while new entries can either be added to that file or added to a new file in that folder.

Church Aspects file[edit | edit source]

Here is an example of an entry in a Church Aspects file:

organised_through_bishops_aspect = { cost = 100 modifier = { development_cost = -0.05 } ai_will_do = { factor = 15 modifier = { factor = 1 is_at_war = no } }}

The entry has three sections: a modifier, an effect, and instructions for AI use. The modifier and effect use any standard modifier/effect which scopes to a country. ai_will_do works in the usual way that it does in decision modding.

Church Aspects GUI[edit | edit source]

This section only applies if adding new religions that use church power.

In order for new religions to utilize custom church power aspects, you must edit the countryreligionview.gui or create a new .gui file in the MODNAME/interface folder (see the above section Religion graphics and interface). Each new religion that uses church power needs to have a section dedicated to it for the gui to work and not instantly crash the game upon either loading the religion in the first place or trying to use church power. Even if you don't plan on making any custom aspects, this is a requirement for non-vanilla religions that use church power.

If the above is not done, the game will crash if you try to use any church aspects for custom religions.

Church Aspects localisation[edit | edit source]

Like personal deities, localisation for church aspects is very simple. Note that desc_ should be added before the rest of the string for description localisation.

organised_through_bishops_aspect: "Organised Through Bishops"desc_organised_through_bishops_aspect: "Bishops used to be leader of a single church, confined to an urban area. Etc."

Centre of Reformation modding[edit | edit source]

A religion uses the Centre of Reformation mechanics if "will_get_center" is included as a trigger in its religion entry. If the trigger evaluates to true, the effect "will_get_center" can be used to add a center of reformation to the country via event or "on_convert" effect. If "will_get_center" evaluates to false for the country, "add_reform_center" on a province in that country will do nothing. Centers of reformation can appear on other continents than province defined as the "center_of_religion" in your religion file as of 1.35. However, in patch 1.34 and below it must be on the same continent.A religion must also have a center of reformation associated with it in /common/religious_conversions/00_religious_conversions.txt for it to use the center of reformation mechanic. Optionally another image can be assigned to the map icons by adding an entry to /interface/mapicons.gfx and changing the value in 00_religious_conversions.txt to the name of the entry added (can use a '.dds' file and have in the entry the path to that file but with '.tga') The first 'frame' of the image is used for provinces with that type of center of reformation, the second 'frame' for provinces being converted by centers of reformation of that type.(Needs verification) Centers of reformation religions must be added (even as a new religious group) to /common/religions/00_religions.txt rather than another file for it to work.

Attributes for the centers can be found in the defines.lua file (note: as of 1.27, Reformation Center base_conversion_speed can be found in common\religious_conversions\00_religious_conversions.txt):

MAX_CHRISTIAN_RELIGIOUS_CENTERSHow many centres of reformation can exist for each religion
MAX_RELIGIOUS_CENTER_SPREAD_DISTANCEThe maximum distance a centre of reformation can convert an adjacent province
MONTHLY_CONVERSION_SPEEDThe percentage at which a centre converts a province per month

This means that the attributes above are common to all religions with centres of reformation.

The vanilla game adds centres in two ways: When the Protestant Reformation and Reformed Reformation events fire, one country is given a centre, and when converting to Protestant or Reformed, a centre of reformation is added if there is a viable province.

Centre of Reformation localisation[edit | edit source]

CENTER_OF_REFORMATIONThe text to display for the effect "add_reform_centre"
REMOVE_CENTER_OF_REFORMATIONThe text to display for the effect "remove_reform_center"
CENTER_OF_REFORMATION_CENTERThe text to display when hovering the mouse over a centre of reformation icon in a province
CENTER_OF_REFORMATION_CONVERTThe text to display when hovering the mouse over a province being converted by a centre of reformation
CENTER_OF_REFORMATION_POSSIBLEThe text to display when converting to a religion and the "will_get_center" clause evaluates to true, and the text to display for the effect "add_reform_centre" in the "on_convert" effect.
CENTER_OF_REFORMATION_NO_PROVINCEThe text to display when converting to a religion and the "will_get_centre" clause evaluates to false
CENTER_OF_REFORMATION_IMPOSSIBLEThe text to display when converting to a religion and the number of centres is already at maximum
CENTER_OF_REFORMATION_ENDDoes not appear to be in-game
CENTER_OF_REFORMATION_NOT_AVAILABLEThe text to display when converting to a religion without the centres of reformation mechanic
CENTER_OF_REFORMATION_HAS_ALREADYThe text to display when converting to a religion and you already have a centre of reformation
CENTER_OF_REFORMATION_CONVERT_PROGRESSThe text to display when hovering the mouse over a progress bar above a province's religion icon showing its conversion by a centre of reformation
CENTER_OF_REFORMATION_CONVERT_ENDDoes not appear to be in-game

Sound effects[edit | edit source]

There are various sound effects associated with every religion. For instance: start_convert_$RELIGION$, religion_$RELIGION$, defender_of_the_$RELIGION$_faith and $RELIGION$_blessings. See Sound_modding.

Vanilla religion names[edit | edit source]

Some religions have a different religion id than expected, the table below has all vanilla religions and their corresponding ids

In game nameid


DocumentationEffectsTriggersModifiersScopesVariablesLocalisationCustomizable localizationRun filesList of event pictures
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