1. What is kamma?
>intentional actions in thought, word, and deed
>the results of intentional actions—past or present—which are shaped by the quality of the intention behind those actions
2. How do actions determine results?
>Skillful intentional acts—those that would lead to no harm for yourself or anyone else—tend toward pleasant results.
>Unskillful intentional acts—those that would lead to harm for yourself or others, or both—tend toward painful results
Kamma is like a seed.
When you plant a bitter melon seed, it’ll tend to produce a bitter melon vine.
When you plant a grape seed, it’ll tend to produce a grape vine.
You can’t expect a grape seed to produce a bitter melon vine, or a bitter melon seed to produce a grape vine.
When you plant a “kamma seed,” it’ll tend to give pleasant results if it’s skillful, and painful results if it’s not.
Acts of generosity, over the long term, tend to lead to wealth.
Taking intoxicants tends to lead to mental derangement.
But how strong those results will be and how long they will take to ripen will depend on many factors in addition to the original actions:
the actions you’ve done before,
the actions you’ve done after,
and the state of your mind when the results are fully ripe.
How your mind acts around the ripening of old kamma seeds is the most important factor determining whether you suffer from those results.
If your present actions (new kamma) are unskillful as they engage with the results of old kamma, you can suffer even from the results of good past kamma.
If your present kamma is skillful, it can minimize the suffering that would come from bad past kamma.
If you treat the pleasure coming from past good kamma as an excuse for pride or selfishness, you’re going to suffer.
If you treat the pain coming from an unskillful action as an opportunity to comprehend pain so as to release yourself from its power, you’ll suffer less.
https://www.dhammatalks.org/books/KarmaQ&A/Section0004.html