Does everything that happen happen because of kamma? Did I stub my toe the other day because of some terrible thing I did 3 lifetimes ago?
In original Buddhism, this was pretty clearly not the case. People are still subject to external forces. If an earthquake (or tsunami) strikes, it’s a natural disaster. Not kammic retribution for a whole village.
After all, kamma isn’t a “force out there”. It is just the simple consequences of our actions. If you don’t believe that lying and stealing lead to bad consequences, try it and see!
The two key things that the Buddha taught about kamma were: whatever situation you find yourself in now (especially however you were reborn) is the result of your kamma. So whatever you want for your own future, you are making right this minute.
Now you might well ask: “Who says?” Or “who controls this process?” But for the Buddha that was all nonsense. Kamma wasn’t a set of rules he made up. Rather it was a description of a natural process. A simple description of the way the world works. It was a law of nature more like gravity than sin. One doesn’t ask, “Who decides whether an apple falls or not?”
Check out this post where I ask the question Is kamma fair?