After a lot of reflection, it's apparent to me that I need a Sympathy or Trust mechanism in Siege. There has to be something that measures the current status of the relationship between characters.
I want the measure to help the game in several ways. It should be asymmetrical, because Amy might trust Brian a lot, whereas Brian has no sympathy for Amy and is intentionally deceiving her. It should also be descriptive, so that it invokes a narrative feel to the game. Lastly, it should affect the actions that characters will perform and, in turn, affect the direction of the story.
I think I can learn a little from The Mountain Witch to start with. But what other games should I check out?