Relationships
Throughout the course of the game companion relationships will evolve based on combat and world interactions. As a companion's relationships improve certain bonuses are unlocked.
Relationship Bonuses
A relationship between two companions reaching +3 will provide them with the [Best Friends] bonus.
Damaging Relationships
Damaging a companion in combat will decrease the relationship status between two companions.
Improving Relationships
Sitting next to one another at the [Campfire] during a rest will slowly improve the relationship between two companions. Fighting next to one another in combat will improve the relationship between two companions.