As culture in Crusader Kings II is in many ways similar to religion, it seems a fitting topic to follow up the installment on religion. Unlike religion, culture has only a minor effect upon the peasantry, most of the effect is instead on your vassals. I'll go into what culture does and how you can use it to your advantage.
The Basics
Culture is an abstract representation of the ethnicity and traditions of the peasantry, and whom nobles identify with. Every culture belongs to a culture group, and is closer to other cultures in the same groups than cultures outside it. Culture mismatch can hurt on both on the provincial level and inter-character relations.
In Crusader Kings II all cultures are created MOSTLY equal. At the most superficial level, Culture affects things like names and portraits. Aside from opinion modifiers mentioned below, the strongest effect of culture is most evident in the cultural specific buildings and retinue units available to your ruler. As indicated by this analysis , the 3 most retinue-cap-effective military units in the game, are the Longbowmen, Schiltron and Cataphracts, each of which are available only to specific culture groups.
Additionally, Tanistry succession is useful for maintaining a large stable empire within dynasty hands, and is again, only available to certain cultural groups (Breton, Irish, Scottish, or Welsh). Of note, the Welsh have access to Longbowmen and Tanistry, while the Scottish have both Schiltron and Tanistry. Finally, there are also a limited number of events that depend upon or are influenced by culture.
The Provincial Level
Every county in the game has a culture representing the major culture there. At game start most realms will be relatively homogenous, with few realms containing more than one culture, and even fewer containing more than one culture group.
However as a realm expands it will inevitably encounter other cultures and culture groups, which will give various penalties, both permanent and temporary.
The permanent penalty (unless culture changes) is a 1% revolt risk for being a different culture than the liege, and 2% if it is in a different group. In addition, upon conquering a region it will get a temporary penalty if it is a different culture. If it is in the same culture group it will get the following penalties (all are doubled if it is of a different culture group):
- Lasts 10 years
- -50% levies
- -25% levy reinforcement rate
- -25% income
As you can see, this means that a newly conquered area will take quite a while before it is of any real value, and even after the temporary penalties disappear you'll still have to deal with the revolt risk, which also reduces tax by 1% per 1% revolt risk.
Also, as mentioned in the instalment on religion, a county being of its liege's culture makes it considerably easier to convert the province.
The Character Level
However as mentioned earlier, culture is not limited to counties alone. Every character in the game identifies with a culture, and this affects their relations with other characters in the same realm.
Being of a different culture will reduce vassals' opinion of you by 10, and by 20 if you're of a different culture group. This penalty is modified by the cultural flexibility in the character's capital county.
Second, being of the same culture reduces character revolt risk directly by 15%. Combined with the lack of an opinion penalty makes same culture vassals much more loyal, and homogenous realms much more stable than others.
Spread of Culture - Character Level
Every character will be born with the culture of his father in a patrilineal marriage, or his mother in a matrilineal marriage. With very few exceptions (being the identify with peasant's culture event), the only way to change this is via the child's guardian. If the guardian of a child is of a different culture there's a decent chance the child will change to the guardian's culture. The mean times to happen are as follows:
- Diligent and gregarious guardian - 30 months
- Diligent or gregarious guardian - 60 months
- No relevant traits guardian - 120 months
- Diligent + shy or gregarious + slothful guardian - 120 months
- Shy or slothful guardian - 240 months
- Shy and slothful guardian - 480 months
As you can see, a culture change happens about 50% of the time if the guardian has no traits modifying the chance, as a child generally has a guardian for 10 years. If the guardian is diligent and/or gregarious it becomes far more likely, as the normal distribution is then centered at 2.5 or 5 years, while on the other hand if the guardian is shy and/or slothful it becomes quite unlikely.
So if you want to change the culture of your child, you should assign a guardian of the desired culture that has the diligent and/or gregarious trait.
Spread of Culture - Provincial Level
Every county has a culture from the start of the campaign, but this can be changed over time. As of at least 1.103, there are two events that trigger on provinces. They both require your top liege to be of the same culture as your self.
The first triggers when the province is of the same religion as the owner and there is at least one province next to it, with both same culture and a ruler of same culture, as the owners.
The second event can only be triggered in a capital and can not happen if there is a province next to them with the owners culture and a ruler of the owners culture. Meaning the first event can't trigger on provinces that the second one can trigger on. One of the following conditions must also be true:
- The owners primary title belongs de-jure to his culture.
- The title of the county is de-jure the owners culture.
- The province owner owns one of the higher titles, of which the county is de-jure part of, and that title is de-jure the owners culture.
The mean time to happen (MTTH) for both of these events is 1200 months. The MTTH is increased cumulatively by 50% by the owner having stewardship lower than 5, 4, 3 or 2. The MTTH is decreased cumulatively by 25%, by the owners stewardship being at least 10, 11, 12 and 13.
The MTTH is further decreased for the first event by 60% and the second by 50% if the owner's culture is Mongol, and by 50% for the second event if the owners culture is Altaic. The MTTH for the first event is also decreased by 25% if it matches the same de-jure rules that the second event requires to trigger.
Tactics
First, as I said in the section on changing character culture via guardian: if you want to change your child's culture, assign him a guardian of that culture with the diligent and/or the gregarious trait. He'll be very likely to change culture. Conversely, if you want to keep your culture pure, be careful who you assign as his guardian.
Second, assign high-stewardship characters of your culture as counts on the edge of your culture. They'll rapidly change the culture to their own, getting rid of the revolt risk.
Third, try to keep your vassals of your culture, as you'll get lower revolt risk and avoid the foreigner opinion penalty.
Finally, prioritize conquering same-culture provinces over provinces of a different culture. Prioritize same culture-group over different culture groups. You'll get less severe penalties that way.
Summary
By keeping your realm culturally homogenous you'll have an easier time controlling it. My tips are as follows:
- If you want to culture-change, appoint a Diligent/Gregarious guardian of a different culture
- Assign high-stewardship characters of your culture as counts in different culture provinces bordering your provinces
- Try to keep a single county per character
- Try to keep your vassals of your culture
- When conquering, prioritize same culture, over same culture group, over different culture group
contributed by Meneth