Bodhisattva Precepts

The Bodhisattva Precepts are a set of ethical trainings used in Mahāyāna Buddhism to advance a practitioner along the path to becoming a bodhisattva. These sets of "restrains" are the main ethical code in Mahāyāna Buddhism and as thus also sometimes called "Mahāyāna precepts".
Traditionally, Buddhist monks and nuns observed the basic moral code in Buddhism, the monastic prātimokṣa or five precepts for laypersons, but in the Mahāyāna tradition, Buddhist monastics and laypersons commonly observe the Bodhisattva Precepts as well. The Bodhisattva Precepts are associated with the bodhisattva vow to save all beings and with bodhicitta.

Overview

Early Buddhism made use of basic moral codes called Prātimokṣa. They included sets of precepts which were expected to be taken by laypersons, like the five precepts, and longer sets of rules for monastics. With the emergence of Mahāyāna traditions, alternative moral codes were established, found in texts such as the Bodhisattvabhūmi, Candragomin's Bodhisattvasamvaraviṃśaka, and the Brahmajāla Sūtra.
Unlike prātimokṣa precepts, bodhisattva precepts could be undertaken by both monastics and laypeople, regardless of gender. Furthermore, bodhisattva precepts were considered to be valid in this life and in all future lifetimes until Buddhahood, whereas other sets of precepts were considered to lapse at death. Formal ceremonies for conferring bodhisattva precepts, along with confession rituals modeled on uposadha practices, are detailed in various Mahāyāna texts. These rites and models influenced later forms of Buddhism in China and Tibet.
Bodhisattva precepts cover a wide range of behavior. Some focus on interpersonal relations, encouraging compassion and altruism, while others address broader responsibilities, such as the prohibition against destroying cities. Interestingly, the bodhisattva precepts sometimes supersede the prātimokṣa precepts; for example, certain secondary infractions suggest that actions typically deemed unethical—such as killing or lying—could be justified if they lead to greater benefit. Notably, rejecting Mahāyāna as the Buddha’s word is a significant infraction, reflecting historical debates over the authenticity of Mahāyāna sūtras.

The Three Collections of Pure Precepts

A common schema for Mahāyāna precepts is the three categories referred to as the "three sets of pure precepts". This category is already found in an early form in the Avataṃsaka Sūtra. It is also found in the Commentary on the Ten Stages Sutra, attributed to Vasubandhu.
The most important source for the three kinds of precepts is the Bodhisattvabhūmi, which explains these as:

Restraining precepts : These are the foundational rules of discipline derived from the prātimokṣa, which aim to prevent unwholesome actions. They thus include the five precepts and, for monks, include the entire Vinaya.
Precepts for cultivating virtuous deeds : These emphasize engaging in wholesome and beneficial actions. These include all good actions that aid in the bodhisattva path, including making offerings to the three jewels, meditating, giving, dedication of merit and so on.
Precepts for benefiting sentient beings : These focus on actively aiding and supporting others. It includes taking care of the sick, protecting people from dangers such as animals or bandits, teaching people the Dharma, using skillful means, comforting people, giving to the poor, rejoicing in the Dharma, praising those who do good and critiquing those who do bad,

The first category aligns with the disciplinary rules of early Buddhism, while the second and third reflect distinctly Mahāyāna ethical principles.
Aside from these, the Bodhisattvabhūmi also includes another set of specific precepts for monastic bodhisattvas. The earliest translation of this text has four main precepts and forty-two minor ones. The four main precepts are:

not to praise oneself and disparage others;
not to be stingy with the Dharma or wealth;
not to be angry, resentful, and refuse to accept another’s apology;
not to slander the bodhisattva scriptures

East Asian Buddhism

East Asian Buddhism makes use of different sets of bodhisattva precepts found in various Mahayana sutras.
Two of the most common sets of precepts are:

the Mahayana precepts found in the Brahmajāla Sūtra and the Sutra of the Diadem of the Primary Activities of the Bodhisattvas. This is a set of ten major and forty eight minor precepts mostly taken by monastics.
the Upāsakāśīla sūtra precepts, commonly taken by laypersons.

''Brahmajāla Sūtra'' precepts

The Brahmajāla Sūtra, translated by Kumārajīva, has a list of ten major and forty-eight minor Bodhisattva precepts. The Bodhisattva Precepts may be often called the "Brahma Net Precepts", particularly in Buddhist scholarship, although other sets of bodhisattva precepts may be found in other texts as well. These precepts are often taken by monastics in East Asian Buddhism.
Typically, in East Asian Mahāyāna traditions, only the ten major precepts are considered the bodhisattva precepts. According to the sutra, the ten major bodhisattva precepts are in summary:

Not to kill or encourage others to kill.
Not to steal or encourage others to steal.
Not to engage in licentious acts or encourage others to do so. A monk is expected to abstain from sexual conduct entirely.
Not to use false words and speech, or encourage others to do so.
Not to trade or sell alcoholic beverages or encourage others to do so.
Not to broadcast the misdeeds or faults of the Buddhist assembly, nor encourage others to do so.
Not to praise oneself and speak ill of others, or encourage others to do so.
Not to be stingy, or encourage others to do so.
Not to harbor anger or encourage others to be angry.
Not to speak ill of the Buddha, the Dharma or the Sangha or encourage others to do so.

Breaking any of these precepts is described as a major offense in the sutra. A fuller description is as follows:
The forty eight minor precepts include refraining from numerous negative acts such as: eating meat, drinking alcohol, not respecting teachers, failing to make offerings or attending Dharma teachings, abandoning the Mahayana, keeping weapons, trading slaves, arson, promoting non-Mahayana teachings, divisive speech, wrong livelihood, selling weapons, persecuting Dharma followers, etc.
These bodhisattva precepts are particularly important in Japanese Buddhism, as many Japanese monastics do not follow the full Vinaya, but do follow a monastic code based on the bodhisattva precepts. Thus, Japanese schools like Tendai and Zen follow these precepts and their main ethical code. In the Sōtō school of Zen, the founder Dōgen also wrote on these precepts in his Busso shōden bosatsukai kyōju kaimon. However, he taught and transmitted only the ten major precepts of the Brahmā's Net Sūtra and not the forty eight minor ones. He combined these ten with the three refuges and the three pure precepts into what is today called the sixteen precepts.

''Upāsakāśīla sūtra'' precepts

The Sutra of the Ethics of a Lay Follower contains six major and twenty eight minor bodhisattva precepts specifically for Buddhist lay disciples. In Chinese Buddhism, this is often done in a ceremony at a Buddhist temple and sometimes a retreat lasting multiple days is required for orientation.
The six major lay bodhisattva precepts in this sutra are the five precepts plus an extra precept which focuses on not "speaking of the faults of bhiksus, bhiksunis, upasakas, or upasikas." Furthermore, the fifth precept has been modified to "not selling intoxicants". Minor precepts include things like making offerings to parents and teachers, looking after the sick, and greeting monastics and elder lay disciples.

Indo-Tibetan Buddhism

In Vajrayāna, the bodhisattva vows became the second of three sets of precepts, preceded by the prātimokṣa vows and followed by tantric commitments. Tibetan literature, particularly the Sdom gsum texts, extensively explores the interrelationship and compatibility of these three sets of vows.
In Tibetan Buddhism there are two lineages of bodhisattva precepts, one from Asanga's tradition and another from Shantideva. Asanga delineated 18 major vows and forty-six minor vows in the "Bodhisattvabhumi" section of the Yogācārabhūmi Śāstra. According to Alexander Berzin, the bodhisattva vows transmitted by the 10th-century Indian master Atisha "derives from the Sutra of Akashagarbha, as cited in ''Śikṣāsamuccaya, compiled in India by Śāntideva in the 8th century" including 18 primary and 48 secondary downfalls.
These Bodhisattva vows are still used in all four major traditions of Tibetan Buddhism. The eighteen major vows which are shared by both traditions are as follows:

Praising oneself or belittling others due to attachment to receiving material offerings, praise and respect.
Not giving material aid or not teaching the Dharma to those who are suffering and without a protector.
Not listening to others' apologies or striking others.
Abandoning the Mahayana by saying that Mahayana texts are not the words of Buddha or teaching what appears to be the Dharma but is not.
Taking things belonging to the Buddha, Dharma or Sangha.
Abandoning the holy Dharma by saying that texts which teach the three vehicles are not the Buddha's word.
With anger depriving ordained ones of their robes, beating and imprisoning them or causing them to lose their ordination even if they have impure morality, for example, by saying that being ordained is useless.
Committing any of the five extremely negative actions: killing one's mother, killing one's father, killing an arhat, intentionally drawing blood from a Buddha or causing schism in the Sangha community by supporting and spreading sectarian views.
Holding distorted views
Destroying towns, villages, cities or large areas by means such as fire, bombs, pollution or black magic.
Teaching emptiness to those whose minds are unprepared.
Causing those who have entered the Mahayana to turn away from working for the full enlightenment of Buddhahood and encouraging them to work merely for their own liberation from suffering.
Causing others to abandon their Prātimokṣa vows.
Belittling the Śrāvakayāna or Pratyekabuddhayāna.
Falsely stating that oneself has realised profound emptiness and that if others meditate as one has, they will realize emptiness and become as great and as highly realized as oneself.
Taking gifts from others who were encouraged to give you things originally intended as offerings to the Three Jewels. Not giving things to the Three Jewels that others have given you to give to them, or accepting property stolen from the Three Jewels.
Causing those engaged in calm-abiding meditation to give it up by giving their belongings to those who are merely reciting texts or making bad disciplinary rules which cause a spiritual community not to be harmonious.
Abandoning either of the two types of bodhicitta.

According to Atiśa, the Prātimokṣa vows are the basis for the Bodhisattva vows. Without keeping one of the different sets of Prātimokṣa vows, there can be no Bodhisattva vow.

Traditional uses

Chinese, Korean, and Vietnamese traditions

The Chinese Chan monk, Yin Shun, wrote of the Bodhisattva Precepts, "To cultivate bodhi mind means to accept the bodhisattva precepts and practice the ten good deeds."
In practice, the acceptance of and ordination of the Bodhisattva Precepts varies greatly depending on the school of Mahayana Buddhism. In East Asian Buddhism, a fully ordained monk or nun ordains under the traditional prātimokṣa precepts first according to the vinaya of the Dharmaguptaka. In the Chinese tradition, this is called the Four Part Vinaya. Then as a supplement, the same disciple would undertake the Bodhisattva Precepts as well.
Monks and nuns are not considered "ordained" by the Bodhisattva Precepts, but rather by the "Four Part Vinaya", while the Bodhisattva Precepts served to strengthen the Mahayana ideals. Similarly, the Bodhisattva Precepts are given to lay disciples to strengthen their devotion to Buddhism as well. Such disciples often take the basic Five Precepts and then the Bodhisattva precepts as a supplement.

Japanese traditions

In Buddhism in Japan, the "Four-Part Vinaya" was deemphasized with the rise of Saichō and the Tendai sect and a new monastic community was set up exclusively using the Brahmajala Sutras Bodhisattva Precepts. All Vinaya ordinations at the time were given at Tōdai-ji in Nara and Saichō had wanted to both undermine the power of the Nara Buddhist community and to establish a "purely Mahayana lineage", and made a request to the Emperor to Later Buddhist sects, which was granted 7 days after his death in 822.
Later Buddhist sects in Japan, including the Sōtō school of Zen, Jōdo-shū and Shingon Buddhism, adopted a similar approach to their monastic communities and exclusive use of the Bodhisattva Precepts. By this time in Japan, the Vinaya lineage had all but died out and Japan's remote location made it difficult to reestablish though limited efforts by Jōkei and the Shingon Risshu revived it for a time. This was further enforced during the Meiji period, when the Nikujiku Saitai Law of 1872 decriminalized clerical marriage and meat-eating.