I'm an atheist. I don't believe in "luck" in the sense of some sort of essence or force, like with lucky 7's, 4 leaf clovers, horseshoes, or the bad luck of black cats, walking under ladders, breaking mirrors, etc.
I do believe in favorable and unfavorable events that occur outside of our control. I refer to that as luck.
If you get good RNG in a video game, I would call that lucky, but I don't think there's anything going on outside of a pseudo-random number generator.
I think some people have had an extraordinary amount of good luck and others have had an extraordinary amount of poor luck, but I think that's mostly a value claim or an opinion. What makes something lucky or unlucky is based solely on whether we evaluate it as being in our favor or not, in the way I use the term.
I might call devastatingly bad or good luck an "act of God," but this is purely by linguistic convention.