Karma is, philosophically, the principle of cause and effect, with the effects of your actions but also your intentions that are take into account measured in point called "Karma points". The more an intention or an action have a major impact, the more you win or lose more or less Karma points. It is classified by three types: good, neutral, and evil. Players always start a new game with 0 Karma points, a neutral Karma. People will behave differently toward you depending upon your Karma, and it's also a factor to unlock certain dialogue options or able to do something specific.