Well, Here goes it. One of the controversial subjects that people debate about. Some attribute luck to just being a random event whereas others say that each one makes his or her luck. In this post, I am going to give the explanation that has convinced me the most about luck. And luckily for you, I did not come up with the explanation :)
So, just to give you a hint, this explanation of luck is based on the concept of Karma and multiple births. Karma basically says that all causes have an effect. Hence, Karma is very straightforward and implies that if you do good, then good things will happen to you.
Now back to Luck. Luck is an unexplainable good (or bad) event that happens to us. In this way, Luck implies that things happen to us without any discernible causes. But then how do we use Karma to explain Luck?
That's when multiple birth cycles come into play. According to the Hindu scripture, we all have go through multiple births and deaths until the soul attains salvation. Hence as far as the soul is concerned, we bring forward our accumulated karma into each life that we take (or the soul takes). So people that seem lucky (for e.g. being born into a wealthy family etc.) have just earned it by their karma in their previous lives. And hence, luck is also earned, the only difference is that as humans we are not able to see it because we can analyze only one lifetime at a time.
Hence the message would be to continue to do good even if results do not follow. We are all accumulating Karma points for our next lives :)