The Law of Karma...
This law is closely associated with the "Law of Cause & Effect"... Yes, we must remember that "As we Sow, We must Reap"... But in understanding "Karma"... we can give us meaning to the retribution we have to make... and to the compensation we must receive.
Every action may have it's karmic reaction... we are free to choose our own actions... (that part is important)... If there are indeed "karmic debts owed" (if there is such a thing as past lives) this law tells us we are still free to choose how we will meet and pay those debts.
The Freedom of Will prevails under the Law of Karma... Karma brings us either "good or bad" depending upon what we have created.