In Buddhism, the term karma is used specifically for those actions which spring from :
- mental intent (Pali: cetana)
- mental afflictions
These bring about a fruit (Sanskrit, Pali: phala) or result (vipāka), either within the present life, or in the context of a future rebirth. Other Indian religions have different views on karma. Karma is the engine which drives the wheel of the cycle of uncontrolled rebirth (saṃsāra) for each being.
Karma in Buddhism
In the Early Sutras
In the early sutras, as found in the Pali Canon and Chinese Agamas, "there is no single major systematic expostion" on the subject of karma and "an account has to be put together from the dozens of places where karma is mentioned in the texts."
In the (Anguttara Nikaya Nibbedhika Sutta) the Buddha said :
- "Intention (cetana), monks, is karma, I say. Having willed, one acts through body, speech and mind".
Every time a person acts there is some quality of intention at the base of the mind and it is that quality rather than the outward appearance of the action that determines the effect. If a person professes piety and virtue but nonetheless acts with greed, anger or hatred (veiled behind an outward display of well-meaning intent) then the fruit of those actions will bear testimony to the fundamental intention that lay behind them and will be a cause for future unhappiness. The Buddha spoke of wholesome actions (kusala-kamma)—that result in happiness, and unwholesome actions (akusala-kamma)—that result in unhappiness.
The theory is not deterministic, as past karma is not viewed as the only causal mechanism causing the present; see below regarding others. Moreover, as M.3.203 indicates, karma provokes tendencies or conditions rather than consequences as such.
There is a further distinction between worldly, wholesome karma that leads to samsāric happiness (like birth in higher realms), and path-consciousness which leads to enlightenment and nirvana. Therefore, there is samsāric good karma, which leads to worldly happiness, and there is liberating karma—which is supremely good, as it ends suffering forever. Once one has attained liberation one does not generate any further kamma, and the corresponding states of mind are called in Pali Kiriya. Nonetheless, the Buddha advocated the practice of wholesome actions: "Refrain from unwholesome actions/Perform only wholesome ones/Purify the mind/This is the teaching of the Enlightened Ones." Dhp v.183.
"I am the owner of my karma. I inherit my karma. I am born of my karma. I am related to my karma. I live supported by my karma. Whatever karma I create, whether good or evil, that I shall inherit." 
Because of the inevitability of consequence, karma entails the notion of Buddhist rebirth. However, karma is not the sole basis of rebirth. The rebirths of eighth stage (and above) Bodhisattvas in the Mahayana tradition refers to those liberated beings who consciously choose to be reborn in a future life in order to help others still trapped in saṃsāra. However, this is not 'uncontrolled' rebirth.
The Buddha explains what having conviction in karma means:
- First, karma really is happening—it is not merely an illusion.
- Second, you really are responsible for your actions. There is no outside force, like the stars or some good or evil being, acting through you. When you are conscious, you are the one who decides what happens.
- Third, your actions have results—you are not just writing on the water—and those results can be good or bad depending on the quality of the intention behind the act.
The Buddha's theory of moral behavior was not strictly deterministic; it was conditional. His description of the workings of karma is not an all-inclusive one, unlike that of the Jains. The Buddha instead gave answers to various questions to specific people in specific contexts, and it is possible to find several causal explanations of behavior in the early Buddhist texts.
In the Buddhist theory of moral responsibility, the effect (phala) or a deed (kamma) is not determined solely by the deed itself, but also by the nature of the person who commits the deed and by the circumstances in which it is committed.
A discourse in the Anguttara Nikaya indicates this conditionality:
A certain person has not properly cultivated his body, behavior, thought and intelligence, is inferior and insignificant and his life is short and miserable; of such a person ... even a trifling evil action done leads him to hell. In the case of a person who has proper culture of the body, behavior, thought and intelligence, who is superior and not insignificant, and who is endowed with long life, the consequences of a similar evil action are to be experienced in this very life, and sometimes may not appear at all.
Incorrect understandings of karma
In Buddhism, karma is not pre-determinism, fatalism or accidentalism, as all these ideas lead to inaction and destroy motivation and human effort. These ideas undermine the important concept that a human being can change for the better no matter what his or her past was, and they are designated as "wrong views" in Buddhism.
- Pubbekatahetuvada: The belief that all happiness and suffering, including all future happiness and suffering, arise from previous karma, and human beings can exercise no volition to affect future results (Past-action determinism).
- Issaranimmanahetuvada: The belief that all happiness and suffering are caused by the directives of a Supreme Being (Theistic determinism).
- Ahetu-appaccaya-vaada: The belief that all happiness and suffering are random, having no cause (Indeterminism or Accidentalism).
Karma is continually ripening, but it is also continually being generated by present actions, therefore it is possible to exercise free will to shape future karma. P.A. Payutto writes, "the Buddha asserts effort and motivation as the crucial factors in deciding the ethical value of these various teachings on kamma."
Other causal categories
- Kamma Niyama — Consequences of one's actions
- Utu Niyama — Seasonal changes and climate
- Biija Niyama — Laws of heredity
- Citta Niyama — Will of mind
- Dhamma Niyama — Nature's tendency to produce a perfect type
The happiness and suffering of all beings,
are due to karma, the Sage taught;
Karma arises from diverse acts,
which in turn create the diverse classes of beings
Karma family in Indo-Tibetan cosmology
The dhyani Buddhas, also called Five Wisdom Buddhas, are built on five Buddha families (Kullas, Buddhakula]. One of them is named the Karma family presided by Buddha Amoghasiddhi/Amogasiddha. The symbol/emblem of that family is the double vajra.
- "Post-Classical Developments in the Concepts of Karma and Rebirth in Theravada Buddhism. by Bruce Matthews. in Karma and Rebirth: Post-Classical Developments State Univ of New York Press: 1986 ISBN 0873959906 pg 124
- Bruce Matthews in Ronald Wesley Neufeldt, editor, Karma and Rebirth: Post Classical Developments. SUNY Press, 1986, page 125 and the top of 126. .
-  Buddhist Karma
- David Kalupahana, Causality: The Central Philosophy of Buddhism. The University Press of Hawaii, 1975, page 127.
- David Kalupahana, Causality: The Central Philosophy of Buddhism. The University Press of Hawaii, 1975, page 131.
- David Kalupahana, Ethics in Early Buddhism University of Hawaii Press, 1995, pages 102-103.
- Misunderstandings of the Law of Kamma P. A. Payutto
- Misunderstandings of the Law of Kamma P. A. Payutto
- Caroline Augusta Foley Rhys Davids, Buddhism. Reprint by Read Books, 2007, .
- Padmasiri De Silva, Environmental philosophy and ethics in Buddhism. Macmillan, 1998, page 41. .
- Mind Training, By Gźon-nu-rgyal-mchog, Thupten Jinpa, Dkon-mchog-rgyal-mtshan. Wisdom Publications, 2005. ISBN 0861714407 
- Symbolism of the five Dhyani Buddhas
- Consciousness (Buddhism)
- Merit (Buddhism)
- Pratitya-samutpada (Dependent Origination)
- Releasing life - as a means to create good karma
- Samsara (Buddhism)
- Twelve Nidanas
- Karma in Hinduism
- Karma in Jainism
- Trikaya del Lama Kunsal Kassapa
- Salvation Versus Liberation, The Limitations of the Paradise Worlds
- Karma by Thanissaro Bhikkhu
- A Buddhist view on Karma
- What is Karma ?
- Dhammapada Verse 128 Suppabuddhasakya Vatthu Story about the Buddha and Suppabuddha, father of the Buddha's former wife Yashodhara
- Misunderstandings of the Law of Kamma by Prayudh Payutto
- The Buddha's Bad Karma: A Problem in the History of Theravada Buddhism Jonathan S. Walters, Numen, Vol. 37, No. 1 (June, 1990), pp. 70-95
- Five Conditions or Laws of Dhamma in Buddhism by Lakshan Bandara