Hi everyone,
If we think of the world as a Simulation (as some scientists claim), then we can think of Karma as the principle that monitors the choices that we make while playing the game.
If we make certain 'wrong' choices or mistakes, we go back and have to play the game again or we lose some points etc. If we play the game as per the rules and make some difficult choices or make some extraordinary moves, we get additional points, we go further up the level, we get special privileges.
This principle is Karma. It enforces the rules (Dharma, Law, duty, righteousness) of the game.
Cheers.
Sriram