The law of Karma (Sanskrit: कर्म), or Kamma (Pali), is a central principle in the Asian religions of Hinduism, Jainism and Buddhism. Although these religions express significant disagreement regarding the specific meaning of "karma", all three groups have relatively similar notions of what karma is.
The universal moral law of Karma provides justice and order to a beginningless and endless universe. Alongside this view is the related notion of reincarnation, or rebirth in Buddhism, which has its roots in the principle of Karma.
Often misunderstood in the West as "cause and effect", in actuality, Karma means intention or cause (accompanying this usually is a separate tenet called Vipaka, meaning result or effect). By the will of the individual, the re-action or effect can itself also influence an action, and in this way, the chain of causation may continue ad infinitum.
According to Karma, performance of positive action results with the reaction of a good conditioning in ones experience, whereas a negative action results in a reaction of a bad response. This may be an immediate result following the act, or a delay may delay the result into future the present life or next. Thus, meritorious acts may create rebirth into a higher station, such as a superior human being or a godlike being, while evil acts result in rebirth as a human living in less desirable circumstances, or as a lower animal. While the action of karma may be compared with the Western notions of sin and judgment by God or gods, Karma is held to operate as an inherent principle of the Universe without the intervention of any supernatural being.
Most teachings say that for common mortals, having an involvement with Karma is an unavoidable part of day-to-day living. However, in light of Gautama Buddha's teachings, as well as in Vedanta and Shaivism, one is advised to either avoid, control or become mindful of the effects of desires and aversions as a way to moderate or change one's karma.
The idea of karma was popularized in the west through the work of the Theosophical Society. Western New Age reinterpretations of karma frequently cast it as a sort of luck which is associated with virtue: if one does good or spiritually valuable acts, one deserves and can expect good luck; contrariwise, if one does harmful things, one can expect bad luck or unfortunate happenings. In this conception, karma is affiliated with the Neopagan law of return or Threefold Law, the idea that the beneficial or harmful effects one has on the world will return to oneself.
In Buddhism, only intentional actions are karmic "acts of will". However, in Jainism, unintentional action is also included into the make up; while Hinduism has several different ideas of karma, not necessarily compatible with each other.