If you mean luck post something happened and saying "he was lucky" opposite to "it was predetermined", i believe in luck, chance, probability.
I don't believe in any person being lucky or unlucky a priori, before something happens.
I think everything is pre-determined, from the thing you will eat for dinner to the movement of a microscopic particle. If you could know all of the information of all the particle in the universe you will be able to predict exactly was will happen. So the only way to change the ''destiny'' would be an external influence outside of our universe. I think that, is how it work. And as humans who are part of the universe and our limited access to little information, we can't distinguish that the thing we are doing were already ''written'' by the rules of the universe.
I feel like I have bad luck in everything I do since I've never won anything, not even a consolation prize, but I also think that maybe everything that happens is planned. What do you think?
I think it's luck. But I am not trying to push it as I believe it's like a string that get tense with every consecutive time. If I got super lucky i will actually try and learn not to push the same luck again.