If real life were like a D&D game:
1) If you got caught up in a convenience store robbery and killed the robber, you'd think nothing of taking his wallet and gun.
2) Any time you needed money, you'd hit up a nearby mall, school, or military base and just help yourself to whatever you found.
3) You'd expect Wal-Mart to take anything you brought to them and give you cash in exchange.
4) Fights in public would be almost unremarked on. You could kill a man who attacked you in the middle of downtown, loot his body, and walk away, without anyone so much as asking you what happened.
5) "He needed killin'" would be a legitimate legal argument.
6) People would walk around, even in town, fully decked out in armor and weapons and carrying their entire life's belongings on their back. They would be ready to fight at a moment's notice, even if they're just eating dinner.