In today’s world of self-help gurus and mystics selling people emotions and nonsense, many have come to believe that karma is some kind of reward and punishment system that is maintained by the Universe, but this is farthest from the truth because what karma really is, is basically the idea of cause and effect.
The Hindu word for karma simply means “action,” thus the concept of that karma is that every action you have taken in your life adds up to bring you where you are today. Ultimately this is no different than the law of cause and effect; there is no magical sky being jotting down your wrongdoings and then punishing them for you later, nor rewarding you for being a good person, nor getting revenge on those who have harmed you or that you have harmed. What is happening is that your actions, or even inaction, have consequences. These consequences, whether good or bad, manifest in reality because of cause and effect.
So to believe that the Universe, God, or whatever force outside of yourself is rewarding or punishing you or anyone else for any reason is an absurd human projection. The fact is that you have created your life up to this point because of your actions or inaction; you project your misfortunes or negative outcomes as being “punished” because your wrong doings obviously have negative consequences but rather scapegoat than accept responsibility.
If you punch someone in the face, your “karma” will most likely be getting punched back. If you give someone a gift, your karma will most likely be that you get one in return, whether it’s gratitude or whatever other form or reciprocity from the other person.
But then there are times where your actions or inaction have the opposite “expected” consequence. Suppose you are drunk and punch your friend in the face but they do not punch you back; your karma is shame and dishonor, as later when you wake up from your drunken stupor, you have realized you have hurt your relationship, being unable to control yourself and acted like an animal. The anger that you allowed to overcome you in order to act out violently is the punishment itself. Do you like to be angry? No. So you have already suffered, and on top of that, hurt your friendship. You’re lucky you didn’t get punched back.
Suppose you should have taken a certain action to prevent something, such as ensuring you took the proper precautions before you went out into mosquito infested territory. Because you didn’t protect your skin with repellent and proper clothing, your karma for your inaction is now you have a ton of annoying mosquito bites.
So as you can now realize, karma doesn’t do anything and is simply a description of cause and effect and how you are responsible for the things that manifest in your life.