In a week where you can hardly move for news and pictures of the royal baby, it pains me to write an article about the same subject – but as we are interested in worldbuilding, and as monarchies and noble families constitute such an important part of genre fiction (particularly, though not exclusively, in high fantasy settings), it seems an appropriate time to take a look at orders of succession.

Traditionally, British succession has been male-preference primogeniture; the order of succession proceeding through the eldest son (and his line) first, followed by the next male children in descending order of age, before moving on to the eldest daughter. In practice, this would mean that if a ruling monarch has two daughters before having a son (as Henry VIII did), the son would still be first in line to the throne.

Recently, however, this has been amended, and the British monarchy now operates by absolute primogeniture; the line descends through the eldest child, with no preference for gender.

For our worldbuilding purposes, then, this provides some interesting background to an important question. What kind of succession does your royal/noble family take? What preferences are given – age, gender, or perhaps something else?

Example: Princess Caroline has been waiting and preparing her whole life to take the throne from her father. She has studied law and philosophy, she is popular and caring, and the people adore her. She knows that she will be a kind and benevolent ruler, with many plans for the wellbeing and happiness of her citizens. One day, however, her mother arrives from an extended trip with exciting news – she is pregnant, and the priestesses say that the baby will be a boy.

We can see here how important considering these ideas in advance might be. Under absolute primogeniture, Caroline has nothing to fear – she will remain the eldest child, and will take the throne as she has planned. Under male-preference primogeniture, however, the new baby boy takes priority, and becomes king ahead of her.

How the story might progress under each of those circumstances is entirely dependent on how such an order of succession works, and we can see how prominently these considerations figure in works like George R. R. Martin’s A Song of Ice and Fire series, in which succession to the head of noble houses forms a huge part of the narrative; were this tweaked, then the characters holding power would be drastically altered, the deals and strategic moves made would need to be different, and the narrative fundamentally changed.

In the Princess Caroline example above, how might she react to the news that she likely will not be queen after all? Will she simply accept that this is the way the world works, or might she fight against it? What of the people? If Caroline is well-loved and her queenhood eagerly anticipated, how might they react to late news that someone else will be ruling over them instead?

Variants of these preferences can, of course, be examined – female-preference primogeniture, where lines proceed through eldest daughters (as has historically been the case in various tribal societies in Africa and South America); ultimogeniture, where the youngest child is prioritised rather than the eldest; or fraternal/lateral succession,where the monarch’s children do not take priority over his/her sibling (when the current king dies, the next in line to the throne would be his younger sister, rather than his son), might lend an interesting side to a fictional hereditary monarchy.

In a fantasy setting, orders of succession needn’t involve anything like the usual real-world considerations;

Example: The High Mage rules over the Nation of Magic, like his father before him, and his grandmother before that. He has two elder brothers and an elder sister, as well as two younger sisters. As infants, they each underwent the Ceremony of Potency, and the Council of Mages determined that of his father’s children, he had the highest latent magical ability, and so gained the right to succeed his father as High Mage upon his death.

Here we can see a different version of the order of succession in operation – rather than looking at the age or gender of the monarch’s children, the line proceeds through the most powerful child, irrespective of their age or gender, followed by the second most powerful’s line, and so on.

This might present some interesting twists – what happens when none of the children of the current High Mage have a higher magical aptitude than their aunts and uncles who have been passed over?

What other aspects might lines of succession take into account? How might these different versions of royal lines affect the power structures of your fictional world?