That's one of the reasons I've wanted to make an RPG for a very, very long time. Always had, in my head, an in-depth reputation system where you get different reputations depending on what you do a la Fallout 1/2, but every NPC reacts differently depending on their own personal views. If you get a reputation for simply killing bandits, some NPCs would treat you like a dispenser of quick justice, whereas others would see you as a murderous vigilante little better than the bandits you kill without mercy. Intelligent opponents would even try to surrender to the PC, and you can either tie them up and send them to the guards or just kill them. If you do the latter in front of people, a lot of them would be horrified, and you'd gain a reputation for being vicious and merciless.