|Please help improve this article or section by expanding it with: information about ‘Introduce New Heir’ action - introduced with Emperor DLC.|
Each country is headed by a ruler. In EU4, rulers are influential in the running of a country, having between 0 and 6 points of administrative, diplomatic and military skill; these skills contribute directly to the nation's monthly generation of monarch power. Rulers may be either a monarch, who as an heir inherits the title from a relative in a monarchy, or an elected leader of a republic or theocracy, chosen by the AI or player at regular intervals.
When generated (by event or by random chance), rulers/heirs have their monarch power set.
The formula for this is simple: .
For lucky nations, the formula is: . (This can equal 7, but will in that case get reduced to 6)
For generation of regencies, the formula is , with lucky nations not getting the "-1" modifier.
|Point Probability||Regular Nations/Lucky Regencies||Regencies||Lucky Nations|
|0||1/16 (2/32)||3/16 (6/32)||1/32|
|1||1/8 (4/32)||3/16 (6/32)||3/32|
|2||3/16 (6/32)||1/4 (8/32)||5/32|
|3||1/4 (8/32)||3/16 (6/32)||7/32|
|4||3/16 (6/32)||1/8 (4/32)||7/32|
|5||1/8 (4/32)||1/16 (2/32)||5/32|
|6||1/16 (2/32)||0||1/8 (4/32)|
The Prussian monarchy guarantees an extra +3 monarch military power per ruler for future rulers, the Mamluk government guarantees an extra +2 monarch administrative power per ruler for future rulers, the Imperial Austrian Monarchy guarantees an extra +2 power per ruler for future rulers, and, with the Mandate of Heaven DLC enabled, the final reform of the emperor of China guarantees +1 monarch administrative power per ruler for future rulers.There is also Albanian mission giving +1 monarch military skill and Bohemian mission +1 monarch diplomatic skill.
- Pirate Kings
With the Pirate King reform the best admiral becomes the Ruler, the skill of the ruler depend on the Fire, Shock and Maneuver pips in particular the formula is
|Sum Pips||Exp. Val.||Std. Dev.|
|Prob. of *at least* total ruler power:||Leader Tot.: 0||Leader Tot.: 1||Leader Tot.: 2||Leader Tot.: 3||Leader Tot.: 4||Leader Tot.: 5||Leader Tot.: 6||Leader Tot.: 7||Leader Tot.: 8||Leader Tot.: 9||Leader Tot.: 10||Leader Tot.: 11||Leader Tot.: 12||Leader Tot.: 13||Leader Tot.: 14||Leader Tot.: 15||Leader Tot.: 16||Leader Tot.: 17||Leader Tot.: 18|
Please help with verifying or updating this section. It was last verified for version 1.30.
- Main article: Personalities
Rulers of AI nations will have personalities that determine how they act. The particular personality assigned to each ruler is strongly correlated with the category of their highest skill, with administrative, diplomatic, and military skill leading to administrator, diplomat, and militaristic personalities respectively. Knowledge of this can help players predict the personality of an upcoming heir.
With the Rights of Man expansion, every single ruler/heir have traits that develop over time. These personalities grant a modifier for the nation as well as changes to the AI's actions. All personalities unlock new options in some events, as well as have events of their own.
Monarchs (rulers of countries with a monarchy government type) rule until death, and have an heir to succeed them and inherit the throne. The system is nearly identical to EU3's system of monarchs, heirs and dynasties.
A dynasty is acquired through:
- Spread from other dynasties
- Pretender rebels
Most countries at game start, in 1444 or in other bookmarks, already have a dynasty. There are some exceptions to this, notably Poland in 1444 which is in the special situation of interregnum.
Dynasties, especially those initially found in powerful countries, can be shared by several countries. A shared dynasty grants a +25 bilateral bonus to relations with all countries with which the dynasty is shared.
Succession and Inheritance
- For the diplomatic effects of royal marriage between countries, see Diplomacy#Royal marriage
- For the mechanics of personal unions formation, see Personal union
Countries ruled by monarchs may arrange royal marriages with others.
Each royal marriage gives 0.1 legitimacy per year, but entering into a marriage with a nation with lower prestige causes an immediate drop of 1-5 legitimacy.
|Available only with the Rights of Man DLC enabled.|
A royal marriage has a chance to produce a consort to the nation's ruler (queen-consort for male rulers or prince-consort for female rulers). The consort will belong to the other nation's dynasty. There is also a chance of getting a consort of a local minor noble dynasty if the nation gains an heir without a consort present. Having a consort will give a slight relations boost with the nation of origin.
The consort will take the role of the de facto ruler in a time of regency - thus lifting the restrictions placed by the regency rule - until the designated heir comes of age. It is possible for the consort to remain in power after the heir becomes old enough through events or in case of death.
A monarch has an heir, who may represent a son, daughter, cousin or other relative. In a monarchy, an heir has an associated claim strength (from weak to strong), which determines their starting legitimacy upon succeeding the throne. Heirs come of ruling age at 15, a regency will otherwise rule until they come of age.
In cases where no heir exists, the mention "No Legal Heir" will stand instead of the heir's name, age and claim strength. If at ruler's death, there is still no heir, the country may:
- Be at the receiving end of a dynasty spread from another country it has a royal marriage with
- Become the junior partner of a personal union
- Face a succession war at the issue of which it becomes the junior partner of a personal union with the winning country.
- Get a new ruler from the deceased monarch's dynasty
- Get a new ruler from a randomly-chosen dynasty among the ones figuring in the game files for the country ("A XYZ noble will accede to the throne")
- Be inherited directly (See inheritance)
The determination of which scenario is to happen rests on several factors, such as, among others, royal marriages, dynasty, rivals, prestige, legitimacy, military strength and total development.
|Available only with the El Dorado DLC or the The Cossacks DLC enabled.|
The player can choose the name of a new heir or re-roll another random name.
If a monarchy has no heir, the daily chance of a new heir appearing is where
- is BASE_HEIR_BIRTH which is 120 if unmodded.
- is 0.5 if the current monarch ruled for more than 30 years, 1 otherwise. This modifier changes from 1 to 0.5 on 1 January in the 30th year of reign. Do note that some starting monarchs ruled before age of 15. Example: starting ruler of Toki, birthdate is 1 January 1406, inaugurated in 23 April 1414, modifier is 0.5 at the earliest game start in 1444.
In practical terms, here are some examples and the resulting probability:
|Situation||Chance of at least one heir in one year|
|Infertile & more than 30 years||0.375||8.61%|
|More than 30 years||0.5||11.31%|
|Trading in dyes||1.33||27.33%|
|Sunni, Shia, or Ibadi||2||38.14%|
|Fertile & Sunni & Trading in Dyes||2.83||49.33%|
Ideas and policies:
Please help with verifying or updating this table. It was last verified for version 1.30.
|+100%||with Sunni, Shiite or Ibadi religion as state religion.|
|+50%||with a ruler which has the ‘Fertile’ personality.|
|+33%||for trading in dyes.|
|+5%||for each royal marriage.|
|+25%||as lucky nation (only AI controlled countries).|
If a monarch dies and an heir is old enough to rule (age 15), there is a separate unknown chance of getting a new heir instantly.
Heir claim represents the legitimacy of the heir to the throne in the eyes of the people, and is a number ranging from 0–100 that is assigned when an heir is generated. Upon ascending to the throne, a ruler's legitimacy will be set to the value of their heir claim. In game, heir claim will be shown only as Strong, Average, or Weak, which gives a rough idea of the value. Having a lower heir claim (Average or Weak) gives a higher chance of pretender rebels arising.
The formula for heir chance appears to be random, but weighted to give higher values, making the majority of heirs have a Strong claim.
Introduce new heir
|Available only with the Emperor DLC enabled.|
- Not in a regency
- Not at war
- Positive prestige
- At least 90 legitimacy
An heir introduced in this way will come from a local dynasty that is different from the country's current ruling monarch and will have a weak claim to the throne.
Further, introducing a new heir will grant a 20-year Restoration of Union casus belli to any country with whom the monarchy has a royal marriage. Allies with a Restoration of Union casus belli may become Domineering and will tend to break any alliance with the monarchy.
|Available only with the Rights of Man DLC enabled.|
A country may disinherit an heir if so is wished, at a cost of −50 prestige. After this action is done the country won't have any legal heir, and will be at risk of falling under a Personal Union, just like any other country without a legal heir (It is not possible to "return" to the disinherited heir).
A country whose ruler is a child (usually because he or she was still a child when the previous ruler died) will be ruled by a regency council, using its skills instead of the ruler's, until the ruler comes of age at 15 years. While in regency, a country cannot declare war unless following the Nahuatl religion (but can still be called to war or be attacked). Additionally, while in regency, the country gets the following modifier:
|+25%||Stability cost modifier|
If a consort is present, they will take the reigns over the nation until the designated heir comes of age, effectively lifting the restrictions of placed by the regency rule (requires Rights of Man DLC).
An interregnum is effectively anarchy; no leadership is in control of the country. This can happen when no heirs are available to a kingdom and its leader dies. It is rare even when a country has no dynasty or royal marriages, as a noble usually takes the throne, but it can occur. Interregnums generally do not last very long; a year is probably average, though they can last much longer. When the interregnum ends, a new leader will be chosen based on the same parameters as if the leader had just died, e.g. a dynasty from a royal marriage, or a new dynasty from the nobility of the country.
Nearby kingdoms in interregnum can be easy to take advantage of. If the player arranges a royal marriage, the new king will likely be a part of the player's dynasty. They will also have no heir. An heirless dynasty with a royal marriage can be Claimed, giving a CB to form a Personal Union. Declaring war against a country one is married into causes stability loss, but this is a small price to pay. It is possible for this tactic to fail, as other nations could form royal marriages as well. A high prestige will ensure that one's dynasty prevails.
In 1444, Poland and Hungary start this way due to their joint monarch having died without issue in the Battle of Varna, and Bohemia also, because its lords did not recognize its previous ruler's posthumous son (Ladislaus the Posthumous) as legitimate. Hungary is scripted to get a specific dynasty (as Ladislaus gets accepted there, and he is a Habsburg), and Poland similarly gets a choice between a PU with Lithuania or a local noble's dynasty. Bohemia does have possible events but there is still the possibility to get the player's dynasty. As such, nearby countries strong enough to take on Bohemia, such as Austria, can get a big boost for the early years if they choose to do so.
|Available only with the Rights of Man DLC enabled.|
It is possible for a ruler to abdicate the throne and allow the next in line to take over the throne and be the new ruler. Note that this will not avoid the stability hit that would occur if the ruler died and succession occurred normally.
- To be able to abdicate, the following requirements must be met:
- Have an heir that's at least 15 years old
- Be at peace
- Have at least 50 legitimacy
- The current ruler must either:
- be at least 60 years old
- have ruled for 20 years
When a monarch dies, the country takes a -1 stability hit. When a monarch leads an army in a battle or a siege, this results in a -2 stability hit instead. Heirs that die either in battle or whilst sieging will result in a -1 stability hit, while dying while not leading any units will not result in any stability hit, although there are certain events that may fire when an heir dies that can cause a stability hit.
In most republics, a group of people hold power over a country until the next election cycle, the length of which depending on the type of republic that is in control. In cases where there are no elections, rulers appear almost identically to those of a monarchy, though they lack a persistent dynasty. Republics do not have heirs, and have the associated republican tradition mechanic, rather than legitimacy. Republics are unable to obtain royal marriages, unless they are either a Noble Republic, Italian Signoria, or a Dutch Republic.
Elections take place at different times for different types of republics. For Merchant, Oligarchic, Constitutional, and Revolutionary republics, as well as the unique Dutch Republic and Ambrosian Republic, the time between elections is 4 years. For Administrative republics the time is 5 years between elections, and Noble republics have 8 years between elections.
Elections will offer a panel of three rulers, each inclined towards one particular skill: Administrative, diplomatic, or military. The ruler will have a 4 skill in that particular one, and 1 in both the others. Re-elections can be done at the price of republican tradition to upgrade the ruler's skills and keep him for another term; he will thus gain 1 in every skill (6 being the maximum), along with a chance to gain 50 power in one category. The republican tradition cost for re-election is tied to the length of the election cycle: 2.5 republican tradition per year of ruling (e.g. a 4-year election cycle costs 10 republican tradition, an 8-year election cycle costs 20).
An election may be held at any time for these republics if the head of the republic dies, and a republican leader does not cause a stability loss on their death, except for deaths in combat or while leading a siege which causes a -1 stability hit.
Theocracies are states ruled by a religious head, and are subject to the devotion mechanic in place of legitimacy. Theocracies are unable to obtain royal marriages with other nations, reducing their diplomatic abilities somewhat.
Heirs of theocracies are chosen through an event, allowing players to choose from various bonuses and potential maluses. Theocratic heirs tend to be older, typically above 40 years, which means they usually do not rule for as long as monarchistic heirs. In this way, theocracies never have regency councils or interregnums, as they always have an heir, and their heirs are always old enough to lead. The monarch power stats of theocratic heirs are generated in the same way as regular monarchs, with a 3,3,3 heir being average and most likely to occur.
Unlike in monarchy, heir of theocracy can't be disinherited.
Chance of death and life expectancy
Every day, a monarch or heir has a daily chance of death where is MONARCH_DEATH (4 if unmodded) for monarchs and HEIR_DEATH (1 if unmodded) for heirs and depends on the age bracket according to the following tables.
Note that the tables assume that the ruler is not a general, that heirs do not become monarchs (which shortens their life expectancy) and ignore special events that may kill a monarch or heir. a is different in the 31-40 age bracket between monarchs and heirs (possibly an oversight).
|Monarch age||a||Chance of death within a year||Chance of death within 10 years||Average life expectancy at start of age bracket|
|Heir age||a||Chance of death within a year||Chance of death within 10 years||Average life expectancy at start of age bracket|
Monarchs and heirs who have been made into a military leader for 5 or more years previous to the current date are also subject to the military leader death check as described for military leaders, resulting in increased chance to die, which is further increased if assigned to an army, and again increased if in a battle or siege.
Note that the life expectancy in general depends on both the age and the time passed since the monarch was turned into a military leader; these tables list values valid just after the button to turn a monarch or heir into a military leader is pressed.
|Monarch age||Average life expectancy when turned into a general at that age and assigned to an army|
|Heir age||Average life expectancy when turned into a general at that age and assigned to an army|
Daily chance of death has no effect on:
- a ruler who was inaugurated less than 1 year ago
- an heir who is younger than 20 years