In Elder Scrolls games of course you can be any sort of person you want. You can choose to help people, choose not to help them, choose to help them but then screw them over, etc. The game has no morality system, but there are mechanisms in place to reward or hinder you based on what you do. In Oblivion, which I played a little recently, a farmer wanted me to help his sons kill some goblins, so I agreed. I went with the sons and killed all the goblins, but then I accidentally swung my sword at one of the sons. Both of them started attacking me. I didn't want a fight, so I tried to run away, but they followed. So I drew my blade and left them both dead on the grass. I took their house key from one of them. I went back and told the father that the goblins killed them. He was heartbroken, but didn't blame me. However I didn't get the monetary reward I was promised for killing the goblins, because he needed it to pay for burials now. So I went back to their farmhouse and used the key to get inside and steal anything valuable as payment for my services. That sort of thing.

As a tangent, because Grand Theft Auto occurred to me when thinking about this, have you ever tried to be law-abiding in a GTA game? Outside of the story missions, I mean. It's frigging impossible. The car physics are so wonky that it's almost impossible to stay on your side of the street, and the other cars go so slow that you can't get anywhere. And the moment you mess up your driving and bump someone, the police try to arrest you and the next thing you know you're firing rockets at SWAT helicopters.