The player can establish relationships with other players and NPCs. If they do, then the actions of one of the characters will reflect upon the reputation of the other character. Choose your close wisely!
Upon establishing a relationship with another character, the reputations of each of the characters will shift towards the other character's, resulting in a 25% change towards the difference.
Newly made characters that have been optionally selected to be related to an existing character will adopt 25% of the reputation earned by the existing character, but will not cause the existing character's reputation to change at all.
Relationships can be terminated, and result in the loss of the initial reputation change, not the changes incurred during the period of the relationship.
Followers
Followers can be recruited and hired to help perform certain tasks, such as running a storefront for you, constructing buildings, crafting goods, or growing food. Most followers require a small salary, which is paid in scrap.
NPC Adversaries
For one reason or another, NPCs will sometimes have a vested interest in tracking you down. Maybe it is your rumored wealth, or it is a member of an opposing faction who thinks your demise would be a great tactical decision. Whatever the case, it is good to keep an eye out for these figures, and sometimes it might behoove you to preemptively put out a bounty on their head.