It would be very different. The super mutants for instance, instead of trying to hit you over the head with a sledgehammer they would probably come over and say something like "You OK there little buddy EH?". And if your car broke down you might get ambushed by people wanting to help you. And if for some reason a real fight did break out it would probably be with sticks because there aren't enough guns to go around. And it certainly wouldn't be to the death, just until someone's gotten a big enough bruise to call it quits. Then they'd grab a beer and compliment each others wives.