Moral luck means that sometimes we can be judged for something that we didn't really control. For example, imagine you accidentally drop a glass but it doesn't break. Some people might think that you were lucky, because you didn't have to buy a new glass. Moral luck is like that but it has to do with more important things, like how people might judge you for something you did even though it wasn't totally your fault. For example, if you try really hard to do well in school but only get average grades, people might judge you even though it wasn't completely your fault. Moral luck means that sometimes it doesn't matter how hard we try, because other things (luck or other people) can affect the outcome.