Many rulers in-game will start unmarried, although others may already have a spouse and children. If you have no other eligible family members to inherit, getting married will be a crucial early step to avoid a sudden game over. Finding a spouse before you unpause is crucial because many of the best choices will be married off to other rulers very quickly.
Marriages and betrothals (an arrangement to become married after both of the betrothed come of age at 16) can be used to secure alliances (which can help you to survive early on with support in wars), or to gain claims on titles, which under specific circumstances can be passed on to children. Marriages have an impact on the prestige of the spouses as well, based on their house and and the relative title ranks of their highest ranking close relative.
Congenital traits (which can potentially be passed on to children, or even augmented if both parents have the trait, and can be either beneficial or detrimental) and fertility, (which is influenced by age, especially for females, who become completely infertile after the age of 45) are important considerations when selecting a spouse. Keep in mind that marrying close relatives (inbreeding) can also result undesirable congenital traits.
Spouses can also help manage your court, based on their own skills (you can direct your spouse to focus on helping with a particular skill by clicking Choose Task under their portrait on the Council screen, or leave them on the default task of Manage Domain, which adds a small degree of each of their skills to yours). An especially important skill for the spouse of a ruler is stewardship, as every five points of stewardship increases a character’s [Characters#Domain|domain] by 1.
A matrilineal marriage will cause any offspring of the marriage to be of the wife’s instead of the husband’s dynasty. This is important for multiple reasons, including determining which court the couple resides at and the inheritance of titles and claims. The potential spouse’s liege (which may be themselves) may prefer a patrilineal or matrilineal marriage, depending on the balance of power between the potential spouses.
To find a spouse for an unmarried character in your court, click on the silhouette with wedding rings to the right of their character in the character screen, or right click on the character and under the Diplomacy heading, choose Find Spouse. To find a spouse for a character from among your own court, right click on that character’s portrait and under the Diplomacy menu, click Arrange Marriage. To select a potential spouse, click on the rectangle that contains the potential spouses’ attributes (not the prospective spouse’s portrait). A hook or a gift may be used to help persuade the character’s liege to allow the marriage. You can narrow down the list of potential spouses by clicking the magnifying glass icon to Toggle Filters, or click the arrow icon, drop-down list or a skill icon to sort the list in ascending or descending order.