The period between one death and the next life is called the bardo in Tibetan Buddhism; Ch'an Buddhism calls it the intermediate body stage. After death, human beings do not necessarily go through an intermediate body stage. If one's karma is overwhelmingly good, one will be go directly to a heavenly realm; and if one's karma is overwhelmingly bad, one will go directly to a hellish realm. Karma that is relatively balanced will go through the intermediate body stage. Where and how this intermediate body will be reborn, no one knows. There are many types of parents creating new life. Depending on causes and conditions, an intermediate body could be born in the animal, the human, or certain heavenly realms.

For these reasons, it is helpful for the living to perform services to help alleviate the karma of the intermediate body.

If people perform services ─ chant, recite sutras, make offerings ─ and transfer merit to the intermediate body, then the being will be helped. For example, if the being was to be reborn in a lower realm, performing services may cause it to be reborn in the human realm, and if it was to be reborn in poor conditions, then the transfer of merit may help it to be reborn in better conditions.

The intermediate body can do nothing on its own. It cannot practice and it cannot create new karma. It can only receive merit from living beings.

According to Chinese Buddhism, the intermediate body stage lasts, at most, forty-nine days. According to the Tibetan Book of the Dead, it can be longer. The time varies for different beings and depends upon causes and conditions. When causes and conditions ripen, a being will be reborn. According to Chinese Buddhism, if, after forty-nine days, the intermediate body does not proceed to the next life, then it will immediately become a hungry ghost or a deity.