How does karmic debt work?

by HELEN
(USA)

I'm wondering how karmic debt from past lives works.

Let's say you did yourself or someone else wrong - murder, theft, or betrayal, for instance. How do the ramifications of these actions show up in your present life?

And in a related question, why do some people never seem to get a break in their lives, while others seem like they fly through life with luck almost always on their side? Everything seems to come easier to them than others, and regardless of how many toes they step on, they always get what they want and don't suffer any consequences.