Succession is a big deal because it determines how your ruler conveys his claims and plots of land in Crusader Kings 3. You want your heir to keep as much of it as possible, making sure your line continues to extend it. You don't want your heir to earn a large chunk of it with his siblings receiving smaller coins. This breaks much of your ruler's work, likely stopping you from growing. Changing inheritance laws is tricky, but it is possible.
You have the opportunity to break tribal inheritance laws when you discover new ones through your culture. To open the culture tree to examine this, click on the candle icon at the bottom left of your character. Almost all cultures from 867 on belong to the tribal cultural era. They are forced to stay in this tree until they learn at least half of the cultural ideas, and it becomes at least 900 AD. Once you've entered the next cultural tree, the early Middle Ages, if you're the leader in the culture, you can choose how you want to change the laws of succession. You can find these options under the Civic Tree, including Hereditary Rule and Royal Prerogative.
However, those who start in the 1066 era with one of these rulers have a better chance of changing the current estate. Many rulers should already be in the early medieval era with their culture.
Now, once you have access to these laws, you need to change them in your realm screen. You can find these options under the Crown icon on the right side of your UI. Click on it, then go to the Succession tab. On this screen, you can see your heir when you die. You can also see which titles they will lose when you die, which is essential to note if you want to keep as many as possible before passing the torch.
On the Succession screen, you can open the option to choose how you want to change your inheritance laws. Unfortunately, there are certain conditions for doing this, even if your culture accepts and understands the law. You may need to increase the authority of your crown, improve the opinion of a vassal, so that they approve your decision and you, and every time you change the inheritance laws it costs you 500 prestige points.
Once you know what to do, it's only a matter of time to make those changes. The kingdom tab also details the authority of your crown, breaking down what these different levels of authority mean. The higher the level of authority, the higher the absolute power of the crown, which gives more power to the ruler. However, your vassals approve of you less because of these rules. It is essential to keep your vassals in mind when changing these laws and to ensure that you choose an ideal heir. They don't have to be your offspring.
