Succession is the distribution of a ruler's titles upon his death based on succession and gender laws of each title.
Upon a ruler's death his titles will be distributed to other characters based upon what succession law they use. This is not necessarily the same for each title; multiple titles can follow different succession laws. However, it should be noted that only the succession laws of titles on the highest tier you hold matter; everything below that will be given out together with the title it is bound to.
There are several different succession laws in the game, each with different requirements and effects. There is no 'best' succession law, which you'll want depends upon your goals for the campaign. Below is a list of all succession laws. Do note that Muslims can only use Agnatic Open (Turkish) succession, while unreformed Pagans can only use Gavelkind (except Mongols, who can also use Ultimogeniture). Succession laws consist of a type of succession, and a gender law.
Succession laws can only be changed once in a lifetime per kingdom/empire, by a ruler who:
- is at peace
- is not in a regency
- has ruled for 10 years
- all direct vassals (for counts and dukes) or all direct vassals of count rank or higher (for kings and emperors) in the territory affected by the change must have a non-negative opinion of the ruler.
- all direct vassals must not be at war with each other. Since this only applies to direct vassals, a particularly troublesome vassal can sometimes be dealt with by transferring that vassal to a higher-ranked subordinate.
Also note that every single one of your direct vassals and direct family members will have a large penalty or moderate bonus temporary but long-lasting opinion modifier as a reaction to a succession change, whether it be gender or succession method itself. This appears to be hardcoded (unmoddable) and largely random as for example female family members will be outraged at a change to true cognatic even if it makes them the new heir, and includes baron-level vassals who in theory should have little if any opinion about it.
At duchy level and lower, a single succession law covers all of a character's titles. However if a character holds multiple kingdom or empire titles these will each have their own succession law, which may lead to different heirs for each kingdom title.
Some characters can never inherit any titles. Bastards cannot inherit unless they have been legitimized, nor can characters who have been made bishops, nor can eunuchs. All other characters can inherit if they're eligible under the title's succession laws.
|Oldest child||Other child||Youngest child||Dynasty||Vassal|
|Gavelkind||Titles distributed between all children. +30% demesne limit||-10||+30||+10||+5||N/A|
|Seniority||Oldest dynasty member inherits||-30||-20||+10||-10||Medium Crown Authority*, or Patrician family.|
|Primogeniture||Oldest child inherits||+20||-20||-5||High Crown Authority*|
|Feudal elective||Every major ruler in the realm votes for the heir||-30||-10||-5||+20||N/A|
|Open||Child (or grandchild) with best titles inherits||-10||Muslim|
|Ultimogeniture||Youngest child inherits||-30||-20||+20||-5||Low Crown Authority*, not pagan (except Mongol) or Muslim|
|Tanistry||Like Feudal elective but all titleholders in realm can vote, and they must select a dynasty member||-40||-20||+10||+5||Low Crown Authority*, Celtic culture or human player|
*Not required for duchy level and lower. Therefore if you are about to create a kingdom title, since newly created kingdoms start with the same laws as your duchy it may be advantageous to change succession laws beforehand in order to avoid the crown authority requirement.
|Open Elective||A generated character inherits, having:
||Burgher or clergy|
|Patrician elective||Only used by merchant republics, person with most 'respect' is elected||Is republic|
|Investiture||If the liege lord has nominated a successor under the free investiture law, he succeeds.
Otherwise, the Pope nominates a generated character.
|Appointment||Title reverts to liege||Only for vassals of holy orders|
|Papal succession||College of Cardinals elects the new Pope||Only for the Papacy|
Succession in the Byzantine Empire is further influenced by the Born in the Purple trait and the Despot honorary title. Characters who have either of these attributes are considered higher in the succession line than those without.
|Agnatic||Only males can inherit||-10 female dynasty members||N/A|
|Agnatic-Cognatic||Women can only inherit if there are no eligible males||N/A||Not Muslim, Tengri, or patrician|
|Absolute Cognatic||Women inherit on equal terms with men||-10 male dynasty members||Basque culture and non-Muslim, or Cathar religion|
|Enatic-Cognatic||Males can only inherit if there are no eligible women||N/A||Unavailable by default, can be modded in, but basic code support exists|
|Enatic||Only women can inherit||N/A||Unavailable by default, can be modded in, but basic code support exists|