Feudal and Clan governments have access to the Crown Authority Law, which can be increased after researching the required Innovation and can be changed once every 20 years. Level 2 Crown Authority requires the Planned Assemblies innovation (Tribal era), while levels 3 and 4 require the Royal Prerogative innovation (Early Medieval era).
Tribal governments have access to the Tribal Authority Law and do not require Innovations to increase Tribal Authority; the law can be changed once every 10 years. The cost of changing the Authority Law scales with a Ruler's Realm Size and to a lesser extent the Ruler's Learning Skill.
|Authority||Level 1 effects||Level 2 effects||Level 3 effects||Level 4 effects|
There are three types of law affecting succession to a title: gender, realm and title. Changing gender or succession laws costs 500 prestige and requires all powerful vassals to either have a positive opinion of the liege, be imprisoned or be terrified.
The gender law determines which gender can inherit titles and claims and who can have more than one partner if its faith doctrines allow. The Visigothic Codes innovation gives access to Equal succession regardless of faith.
The realm succession law determines which and how many heirs will inherit the character's titles upon death. All children will gain claims on titles they did not inherit regardless of the realm succession law.
Feudal Rulers can apply a Title Succession Law on Duchy, Kingdom or Empire titles at the cost of 1500 Prestige. Note that this will only affect the succession law for the title in question; other titles the character holds will be distributed normally. (This can lead to unexpected results.)
|Law||Direct Vassal Opinion||Effect||Requirements|
|Feudal Elective||+10||The Ruler and all direct De Jure Vassals of one or two Ranks below the Title can nominate an Heir from amongst themselves and the Close Family of the Ruler.||Not Anglo-Saxon culture|
Not North Germanic culture group
|Saxon Elective||+5||The Ruler and all direct De Jure Vassals of one or two Ranks below the Title can nominate an Heir from the most Powerful Vassals amongst them, the Ruler's Legitimate children, and any other valid Claimant.||Anglo-Saxon culture|
Title rank is kingdom or empire
|Scandinavian Elective||+5||The Ruler and all De Jure Vassals (except Barons) can nominate an Heir amongst the Ruler's Extended Family and any available Claimants. Voting Power in this Succession Law is influenced by the Elector's total Domain Development and Capital Popular Opinion. Known criminals are not eligible Heirs, but their descendants are. Grandchildren of non-criminal, living children are not eligible Heirs.||North Germanic culture group|
|Tanistry Elective||+5||The Ruler and Vassals of one or two Ranks below the Title can nominate an Heir - the Tanist - from among the members of the Ruler's Dynasty. Vassals will tend to favor older, distant relatives over Close Family.||Brythonic or Goidelic culture group|
Title rank is kingdom or empire
|Princely Elective||+10||The Emperor and the seven Prince-Electors can nominate an Heir from amongst themselves, any Legitimate children and siblings of the ruler, as well as any other major De Jure Vassal of the Empire. If an historical elector Title is held by infidels or does not exist, another De Jure Vassal will take its place. This Succession Law places a significant importance on Faith and Piety.
The Electoral Titles for this realm are the Counties of Cologne, Mainz and Trier, and the Duchies Bohemia, East Franconia, Ostfalen and Ostmark.
Removing this Law costs 10000 Prestige. Having this Law active increases the vassal limit by 20.
|Holy Roman Empire title|
- Monitor which holdings will be lost upon succession: Click the "Succession" tab under the "Realm" window.
- Get out of Confederate Partition as soon as possible: It is the only succession law which creates new titles upon succession, thus almost guaranteeing a split in the player's realm unless the player restricts the realm to the De Jure Counties of their primary duchy or kingdom. If expanding, they should aim to occupy at most 50% of other duchies/ kingdoms to avoid having enough land to cause a split.
- Tribal realms are locked to Confederate Partition; they must reform to either Clan or Feudal government before being able to select other succession types.
- If you have a partition succession and multiple heirs, you may want to remove all heirs except one, if possible, so that your primary heir inherits all titles. This is difficult to do, but there are ways. (Sons with low prowess can be forced to serve as knights, and may die in combat. If you are the dynasty head, you can disinherit all heirs but one. If you have the sadistic personality trait, you can use murder schemes against your children. Etc.)
- If an event allows you to choose an "elective" title succession law, be aware that this only applies to the title in question. For instance, if you play as the King of Scotland (Goidelic culture group) and you have partition succession, switching Scotland to "Tanistry Elective" will not affect how your duchies and counties are distributed. When you die, if your primary heir is not your tanist, you may find yourself playing a new king with very few holdings and a great deal of internal "border gore".
- If you have another kingdom in addition to Scotland, then Scotland will be completely removed from partition. All your titles under de jure Scotland will be inherited by the tanist, and your children will inherit the second kingdom and other external titles. This will split your former realm but you will not lose all your domain. On the other hand, if this second kingdom is also under tanistry, it will also be removed from partition and your children will only divide your titles outside of both kingdoms. This will not split your realm, but the electors in both kingdoms have to elect the same person.
- If you only have one kingdom with tanistry and partition, you can save your domain by adding tanistry law to your duchies. This is expensive (1500 prestige) but such a duchy will be removed from partition and its de jure counts (which is usually only you) will vote for the successor of the duchy title. You should appoint the same person who is going to inherit the kingdom.
"Succession Laws EXPLAINED", forum thread: https://forum.paradoxplaza.com/forum/threads/succession-laws-explained.1419049/