Originally Posted by
Shoebopp
Each character has a hidden base loyalty that's generated upon character creation (adoption, coming of age, marriage, etc). So some of it is genetic. For events you have control over like adoption and marriages, carefully approve characters with high loyalties. The trait triggers for adoption and marriages are actually influenced by ethnicity. Some factional ethnicities are considered more (or less!) loyal. For example, Aedui have the Volcae ethnicity which pushes the character to be more loyal. Pergamon meanwhile has the Bithynian ethnicity which pushes them to be less loyal. Read the trait descriptions carefully - if the ethnicity is sketchy, and the loyalty reflects that, send that suitor away!
Now that nature is covered, let's move onto nurture. Here are the ways you can influence loyalty
1. Holding court: Put your faction leader in your capital, and all governors will VERY slowly gain loyalty. Put your faction leader in your capital, and have a few characters in that same settlement, and they'll also VERY slowly gain loyalty on top of the prior trigger. Likewise, if your faction leader is out of your capital but you have characters too close (10 tiles?) to the capital, they'll slowly lose loyalty. This is to represent the FL holding court on one hand, and characters growing ambitious in the FL's absence on the other hand.
2. Faction leader capabilities - If a faction leader has more than 5 influence or command, then all characters with less than 5 influence or command slowly gain loyalty. Likewise, if a faction leader has less than 5 influence or command, then all characters with more than 5 influence or command will slowly lose loyalty. So just keep conquering with your FL
3. Supervisor/Warmonger/Brutal - a Supervisor becoming satisfied from governing a City or above settlement will instantly gain like 3 loyalty points. Meanwhile, a Supervisor governing a Large Town or below settlement, or being forced to fight too many land battles, will become unsatisfied and lose around 3 loyalty points. Same goes for Warmonger - fight lots of battles and he'll become Satisfied. Sit in a settlement and he'll become Unsatisfied. Brutal - same. Sack and Enslave and raise taxes, he'll be happy. Occupy and lower taxes, he'll become disillusioned.