Darkness Falls: Livernia
Here is the alternative rules we will be using for Livernia
Fear saves can be brought on by being out-numbered or seeing your best fighter go down, encountering monsters much larger than you, learning your enemy is immune to your attacks and other such reasonable stimuli.
Fear saves can be modified by knowing your weapon will hurt the damn thing, or knowing someone you love is in danger. A minor fear failure just means you are shaken but more severe failures can result in you fleeing or being panicked.
Horror is a little more intangible but also more fun. Horror is the feeling that you are seeing something that should not be. The examples given are watching someone torn limb from limb, seeing a friend turn into a monster or learning that you killed an innocent while possessed.
Rule wise they’ll be effected by a d20 role they’ll be pluses and minuses which will affect your DC
A more malleable concept Touchstones are things that bind your character to both the world and to the story. Your characters are going to be fighting for his/her life so why do it and because i ’m an adventurer is not a good answer.