I just Kill for personal defense or for the resources, but just if it's the last option it remains. I try to make the person in front of me defenseless and i just take what i need from his backpack and so, then i let him go. Most of the times i try to do this i got killed and robbed, other times i make friends, other times i just have to shoot the guy, so going on i'm beginning to trust less the other people and going to shoot much more than i was used to do.