.If you do "good" things, like help others, be generally agreeable, work hard, and avoid causing trouble, things will work out positively for you most of the time.
In contrast, if you hurt others, are disagreeable, lazy, or cause trouble for no good reason, things probably aren't going to work out so well for you most of the time.
These effects are a byproduct of human social systems. We are all dependent upon each other, and have to cooperate to survive. THAT is a natural law. The more often you cooperate, the more people will cooperate with you, and the better you do in the long-term. Cheating others might get you sizable benefits in the short-term, but will usually harm you in the long-term.
Of course, there are exceptions. There are innocent people who are wrongly convicted of crimes and are sentenced to long prison terms. There are rapists and murderers who are never caught, or have the resources necessary to game the system and avoid punishment for their crimes. Wall Street executives are able to steal millions of dollars by defrauding investors and live the rest of their lives in luxury. Public school teachers, who have some of the hardest jobs in the developed world, are almost universally underpaid and are subjected to almost prohibitive budget restrictions and moronic performance metrics.
Of course, if you believe in reincarnation, an evil person who gets away with their crimes in their present life will be punished in a future life, and a good person who struggles in their present life will be rewarded in a future life. Such metaphysical concepts are a matter of personal belief, but if you look at observable reality, you can't say that karma is a law of any sort.
