Well then you know about Hinduism Karma it also states that "whomsoever shall cast sins to his account shall get back all in there present life" However this concept is not followed for higher sins like for example ( se*ual amusement etc which Hinduism states the punishment of 6000 years of hell burning and after that the soul take the girl/boy whomsoever soul se*ual abused then same strike with that sinner soul and in his next life he take birth as "A person not a guy nor women" when he complete his that life he again can return his soul path....) Karma is not revenge but it surely is a PUNISHMENT if someone do wrong to you THEN YOU HAVE RIGHT TO KNOCK THE DOOR OF HEAVEN TO YOUR GOD To ask for justice (Depends upon religion maybe ask direct gods of justice) according to Hinduism where as small things of sin (lie,thieving things,Bother fight for no reason etc ) Karma strike eventualy sooner or later So in the end karma spells are just to ask gods to do justice BECAUSE ONE CAUSE CAN BE THIS I can curse badly but no instead of it I ask the god to decision
Case 2 :-If person meant to live longer but he do much evil work enough to fill his sin pot then gods himself will snuff his life candle before his actual time KARMA decides all now vice versa case for those who are meant to die after short life if they do good karma their life will be increase It's Hinduism and Chinese Taoism ....
Actually Reincarnation have "not everything" to do with karma it depends upon you where you want to have reincarnation only you'll have good life or bad and what will be you in this life (it will depend upon your Birth chart zodiac planets your name teachings bla bla ) This all is governed by karma ....
(Some people of Hinduism say KARMA have NOTHING to do with reincarnation because all good sins soul get back in heaven and then take birth again with free of everything lol I don't know it's truth or not don't remember my past death hehe )
Oh and sorry if it sound bit harsh it really isn't though hehe lol :-) Blessed Be