Maybe mine was a bad example because Im not trying to cherry pick the best possible examples to serve my argument. My argument is really that the reputation system in FNV does a better job as a role playing element than the karma system in FO3. Going back to the Megaton example, what consequence does this really have on the world? When your karma falls, what happens to you as a result? What factions are there that saw that action I took as being disgusting and evil? How do they react? The reputation system in FNV actually impacts how each faction views you which leads to actual consequences, like the Legion sending executions squads because they now vilify you. A number of different actions, such as completing quests for the NCR and increasing your reputation with them, leads the Legion in this direction. This leads to a state in the game where you are literally role playing a specific character, not just the courier, whereas in Fallout 3 you will always just be some guy chasing his father, being given illusory choices and consequences along the way, i.e. nuking megaton.