The Pāḷi word kamma means ‘action’ and in Buddhist doctrine refers to any intentional mental, verbal or bodily act. The Buddha says: ‘I say that intention is kamma, because having first intended one acts with body, speech or mind.’(A.III,415). According to the Buddha, every intentional action modifies our consciousness, thus building our character and thereby influencing our behaviour, our experience and consequently our destiny. Positive intentional actions (motivated by generosity, love and wisdom)tend towards consequences that are experienced as positive, while intentional negative actions (motivated by greed, hatred and delusion) tend towards consequences that are experienced as negative.
(1) Everything which happens to us is the result of our past kamma. In actual fact, Buddhism recognized at least four other broad causes of why things happen, including because of the operation of natural laws (dhamm niyāma), biological laws (bīj niyāma), physical laws (utuniyāma) and psychologica laws (cittaniyāma,As.854; A.III,62).
(2) We can never escape from the consequences of our past actions. If this were true then we would be completely determined by our past and be unable to change and attain enlightenment (A.I,249). What Buddhism does teach is that several strong intentional good actions may very well modify or even cancel out a bad action and vice versa (Dhp.173). Thus it is correct to say that we are conditioned by our kamma rather than determined by it.
(3) Our experiences in the present life are due to what we did in our last life and what we do now will have an effect in the future life. In reality, many of our actions have a result immediately or soon after we have done them, i.e. in the present life
(4). The fourth common misunderstanding is what might be called ‘kammic naivety,’ i.e. if you kick a monk in this life you will be reborn with a club foot in your next life, if you swear in this life you will have bad breath in the next life, if you are generous in this life, you will be rich in your next life. This, of course, is rather silly. Because kamma is primarily psychological (i.e. intention), its manifestation is primarily psychological. It only affects our physical form and circumstances to the degree that the mind can have an influence on the physical, as, for example, when prolonged worry can cause or aggravate physical illness. The main effect kamma has upon us is how we feel (happy, neutral or unhappy) and which realm we will be reborn into. See Determinism.