Oh joy.
edit: Luck or fortuity is good fortune which occurs beyond one's control, without regard to one's will, intention, or desired result. There are at least two senses people usually mean when they use the term, the prescriptive sense and the descriptive sense. In the prescriptive sense, luck is the supernatural and deterministic concept that there is a force which prescribes that certain events occur very much the way the laws of physics will prescribe that certain events occur. It is the prescriptive sense that people mean when they state that they "do not believe in luck." In the descriptive sense, luck is merely a name we give to events after they occur which we find to be fortuitous.
The laws of probability must exist, whether or not they are merely an automated system or there is an invisible hand (Lady Luck) calling the shots is something else again.