There’s two concepts of moral balancing. The philosophers of antiquity would talk about it in the context of finding a good balance between being too radical and being too normal. The psychologists of today talk about it in the context of how we have a tendency to give ourselves permission to be bad, if we feel we have been good.
Although, the former would make a good subject in itself, I’m talking about the latter here.
The idea is that we have a set point on how good we want to be. Subconsciously we give ourselves points for behaving well and deduct points for behaving badly. If I eat vegetarian for a couple of days, I give myself permission to eat pizza. If I give some money to a charity, I’ll give myself permission to be rude to customer service (not really, I’m not rude to them unless they are really going out of their way not to help me). If I put on the seatbelt, I feel like I can drive a bit faster (again, I don’t really do this, but many people do). Some people (not all) become smug if they recycle. We all do it in many ways. Its just hard to identify the ways we do it in, because our brains are faulty.
In the context of RPGs, this could be a tool. Depending on the game, of course. If your character is supposed to be a paragon of good, you don’t do bad things. You just don’t. But if you are going for something more realistic, this could be a good way to bring depth to your character.
Using a set point is not a good idea here. Rather, emphasize different acts differently. How do the bankers who destroyed the economy some years back sleep at night? They give some money to charity. Sure, they pretty much stole billions and give maybe tens of millions away, but if they give these acts different multipliers in their heads, they can balance them out in their own minds.
On the other hand, a good person would give good deeds small multipliers, so that they need to do a lot of good to make up for one bad deed.
Of course, in reality this isn’t this simple. We become accustomed to doing some things, so they don’t matter as much anymore. Bullies can live with themselves, because the act itself becomes normalized and doesn’t register in any way.