How To Make Your Own Religion In CK3

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How Your New Faith Will Interact With Others

Faith is a massive part of Crusader Kings 3. It dictates multiple aspects of life and can be a great help or a hindrance to your plans. It has rules for gender, marriage, the role of the clergy, and even the treatment of witches.

Christian and Muslim nobles play chess in Crusader Kings 3.

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Not sure which character to pick in Crusader Kings 3? Try someone from one of these Cultures!

It makes sense, then, that you would want to embrace a faith that has rules that align with your goals. And if one doesn’t exist, create one. Faith creation can be an expensive process that requires a lot of preparation and planning, but there are ways to make it easier.

Updated February 16th, 2025 by Hilton Webster: After making a new Faith, you actually have to make sure the rest of the world accepts you, too. We’ve updated this article to reflect how pre-existing Faiths will interact with your new one, and how all of this affects the laws you can enact in your realm.

How To Create A Faith

The faith creation menu in Crusader Kings 3

Creating Your Faith

To begin creating a new faith, open the religion screen and click the Create New Faith button at the bottom.

The first thing to know about faith creation is that it costs piety which is earned over time, at a rate based mostly on your Learning skill. During faith creation, you will have to select the tenets that it will follow and the doctrines it will possess.

The game uses your current faith as the basis of your new faith and the cost of creation will increase depending on how different the new faith is in comparison.

An easy way to offset this cost would be to swap faiths for a close match, but this too costs a variable amount of piety.

Once you have selected your new faith’s doctrines and tenets, you can name it, give it a description, and pay some piety. It’s important to really think about your future plans when it’s time to choose your tenets and doctrines, as they can drastically affect your gameplay. Here are some tips on selecting good ones:

If your succession law divides your land amongst your children or all of your viable heirs, keep in mind that going for gender equality will make it more likely that you end up splitting up your nation in ways you may not have anticipated.
Changing Clerical Appointment to Temporal allows you to choose your own Court Chaplain. This gives you greater control over your council and enables you to give the job to a powerful vassal in order to satisfy their needs. For further control and more flexibility, make the title revocable.
Embracing Polygymy or Consorts & Concubines makes it far easier to create heirs for male characters, which is useful if you have concerns about succession or wish to create a huge dynasty.
While it may be tempting for some players to legalize everything when it comes to Crime Doctrines, remember that crimes lead to secrets and secrets lead to Hooks – which can be very useful in controlling your realm.
The Mendicant Preachers tenet will make converting the rest of your provinces quicker and is a good option for new faiths.
The Pursuit of Power tenet is very expensive in terms of faith, but is fantastic for expansionist strategies as it grants powerful Casus Belli.
Similarly, the Sacred Lies tenet is a great choice for players who like using Intrigue-centric strategies as it provides bonuses to Agent Acceptance.

There are some things that are important to keep in mind when considering creating a new faith.

You can only create a new faith if you are at peace.
You can only create a new faith if you are at least a duke – counts cannot create a new faith.
When you create a new faith, you and your immediate family will automatically convert. Additionally, your realm capital will also convert.
Your vassals can convert on their own, but you also have the option of trying to sway them to your new faith in exchange for money.

How Culture And Faith Interact

For the most part, any Culture can practice any Faith. While it might be odd and difficult for an Islamic leader to pop up in the middle of Europe, there is nothing technically stopping it from being possible. However, some aspects of Faith extend beyond your personal and foreign affairs, and affect your realm directly.

The biggest impact that Faith has on your realm is on Gender Law. When it comes to Inheritance, this is Male Preference by default in most Faiths, and few Cultures have the Egalitarian Ethos required to enact this either. However, you need a Faith that is Equal and a Culture with the Egalitarian Ethos to be able to change your Realm from being Male-Dominated, or change Inheritance law to favour women or treat them equally.

Conversely, some Cultural Ethos make it easier to change Faith. Cultures with the Spiritual Ethos gain more Piety every month by default, and get a 20% reduction in the Piety cost to both Reform a Faith, and create a brand-new one.

Creating a new faith in Ironman mode will earn you the It’s not a Cult! achievement.

How To Afford It

The pilgrimage event chain in Crusader Kings 3

Creating a faith can get extremely expensive if it is drastically different from your old one. Luckily, there are some things you can do to boost your piety gains.

If you have the luxury of being able to choose your heir, you may want to pick one that will be great at earning piety. Things to look out for are a high Learning skill (which directly affects your monthly piety gain) and the Zealous or Humble traits. If you have a faith that allows you to pick your own Court Chaplain, giving that job to your heir will also increase their piety before inheriting.
Having virtuous traits as opposed to sinful traits is also useful. Which traits are considered virtuous or sinful depends on your current religion – you can tell virtuous traits by the shining green border around them on your character screen.
Going on a pilgrimage and acquiring the Pilgrim perk will also increase piety gain. Try to do this as often as possible (once every 15 years) and go on the longest pilgrimages available to you for the highest instant piety gain. Muslim characters can also undertake the Hajj for similar results.
The Church and State perk from the Theologian tree of the Learning lifestyle increases your piety gain by 100 percent if your current faith has Lay Clergy. If the faith is Pluralist, the Defender of the Faith perk in the same tree increases piety gain by 20 percent.
Owning certain provinces can also provide a boost in piety. These are either the holy sites of your current religion or the locations of famous buildings of worship such as Canterbury Cathedral or Notre Dame.
Taking the decision to go Celibate will also increase piety.

The Theologian perk tree is extremely beneficial to characters who wish to create a new faith. Not only are there perks that can increase piety gain (as detailed above), completing the tree provides the very powerful Theologian trait which increases piety gain and your character’s Learning skill.

Perhaps the most useful element of the perk tree, however, is the Prophet perk which reduces faith creation cost by half.

How Your New Faith Will Interact With Others

Faith Hostility

When you create your new Faith, you will note that the farther apart the new Doctrines and Tenets you choose are, the more Piety it costs to establish them. However, this isn’t just a punishment for straying further from your original Faith, but also an indicator of how that same Faith will treat you after you convert to your own.

This is what Faith Hostility encompasses. The further your Tenets and Doctrines Stray, the more oppositional your original Faith will be to your new one. This is important to keep in mind, as you won’t immediately want a Holy War declared on you if you don’t have the military force to back it up. If your vassals don’t convert either, you will find it much harder to defend against schemes and factions.

Here are each of the Faith Hostility levels and what each of them does:

Righteous – This Faith is on good terms with others, and can usurp the titles of practitioners of faiths that consider them Righteous.
Astray – This Faith has some differing beliefs, but is similar enough to still co-exist together. Titles can still be usurped, though followers of other religions will have a slightly negative opinion of you.
Hostile – This Faith has dramatically strayed from others, and can no longer usurp titles of rulers of opposing Faiths. Holy Wars and Holy Orders can be used against this Faith.
Evil – This Faith’s existence is oppositional to others. There is a major opinion penalty, Holy Wars will be even more likely, and inter-faith marriage outside of this Faith is exceptionally rare.

After your new Faith is formed, there is no way to change the Faith Hostility of others unless you reform your own Faith to be more like others.

Fervor

This naturally leads into Fervor, which is the general strength of your Faith among its practitioners. A high Fervor will have a very faithful following, making them very difficult to convert to other Faiths, and makes the appearances of Heresies exceedingly rare. A low Fervor has the inverse effect, making characters liable to change Faith and make brand-new Faiths in the form of Heresies to appear.

When your first make your new Faith, it will have a very high Fervor owing to it being a new chance and its adherents being on a fairly small scale. Fervor decreases naturally, and does so more dramatically the older it is and the more followers it has. There are a few other ways to affect Fervor though, such as:

Certain decisions, such as those made while traveling or while Holding Court.
Holy Wars. Winning will decrease your Fervor, while losing will increase it. This is due to the winners feeling comfort in the dominance of their Faith, and the losers feeling a need to fight for their Faith.
Heresy outbreaks will dramatically increase the Fervor of the Faith that is spreading.

In general, Fervor tends to stay fairly steady unless you are actively spreading it and interacting with other faiths.