Karma is a concept of spiritual balance; an action taken will affect the future of that individual.
Karma is the after affects of things one does in one's life. All actions taken will have repercussions down the road. Karma also plays a role in Reincarnation. According to Ryuwan Karma is the built up accumulative of sorts that one aquires throughout their life. Unless it is undone upon or near death than that person cannot reincarnate. If the Karma is not undone than one will not reincarnate until it has dispersed after a certain amount of time and the longer one has lived the longer that period of time will take. When Reincarnated one does not necessarily reincarnate as the same species as seen with West who reincarnated into a human who is not even of the same gender (though it would be impossible for a witch to reincarnate as a witch at birth given that human females become witches during their lives.) The sole way to bypass this otherwise absolute law is for East's powers of Death and Reincarnation to allow one to reincarnate at an earlier time. A possible side effect of East's power is that West's Mana has come to rest upon her current incarnation despite him being a male.
Karma is a basic and fundamental concept in Buddhism where it is believed to be the Law of Mortal Causation. One of the Five Niyama (Five Orders of Processes). Karma Niyama is the order of act and result. According to the belief systems of Buddha one is singly responsible for one's own happiness or misery depending on the choices and actions that one makes in life. These actions may also affect another and the happiness/misery caused to others will also reflect upon the instigator.
The concept of Karma is that the instigator of a certain event will be affected by the affect's outcome directly or a separate outcome that will indirectly influence that person depending on the role in another event regardless of how loosely or closely the two events are related. Simply put if one instigates a good deed then he will gather good towards himself, but if one does an evil deed than he shall reap evil down the road.
The word Karma means Action, Deed, or work which directly refers to its spot within the Niyama in modern Buddhism.
Early texts usually refer to Karma more along the line of meaning wise when referring to someone and knowledge when referred to as itself.