Moral Luck: You can be declared morally responsible for something that is not completely under your control...or not? Typical example is the drunk trailer truck driver. If he arrives home without an accident, do you blame him as much as you would if he, completely by chance, runs over a little girl instead? If you do, then you would have to have a very severe application of moral guilt, for a lot of actions that all of us take almost every day. But if you don't, then you are saying that the action that he did by volition (drinking) is not determining the morality endpoint, but the action that he did by chance (running over the little girl) is. Therefore you could have morality decisions depending of random situations.
Double effect: Is it worse to harm a person as means to save others versus harming that person as a side effect of you saving them? This to me it is a specific case of the moral luck dilemma, because if you know in advance that the side effect is going to happen, then you knowingly are harming the patient. On the other hand, if you don't know, then we are going into the moral luck question again.
Action and Omission: Is it morally worse to cause somebody to drown, or to not save that person (taking into account that saving the person wouldn't affect you in a significant fashion) if you are able to?
One of the problems that I see with answering these questions (and I suppose it is one of the main ones with any kind of philosophical questioning) is that it has a large number of suppositions integrated in the questions. And this makes it difficult to think and discuss with others, as they may have different assumptions about the same premises. It has to do with how do you view determinism versus free will, and the responsibility of the individual over the societal ones.
Again, an interesting read.