Full Idea
Moral luck involves one's character, the antecedent circumstances of the act, the actual circumstances of the act, and the outcome of the act.
Gist of Idea
Moral luck can arise in character, preconditions, actual circumstances, and outcome
Source
Thomas Nagel (Moral Luck [1976], p.28)
Book Reference
Nagel,Thomas: 'Mortal Questions' [CUP 1981], p.28
A Reaction
Meaning, I take it, that there can be luck in any one of those four. A neat slicing up that doesn't quite fit the real world, where things flow. Helpful, though.