Most Tibetan Buddhists take vows at some point—during initiations, for example. This excerpt from Great Perfection: Outer and Inner Preliminaries by the Third Dzogchen Rinpoche describes the very concrete results of keeping—or not keeping—certain vows.
The Secret Mantra’s samaya vows of the masters of awareness are twofold: those associated with maturing empowerments and those associated with liberating instructions. Generally speaking, there are a hundred thousand different categories of samaya, out of which there are twenty-five essential samaya vows. These, however, can be condensed even further into the three samayas of enlightened form, speech, and mind. As stated in the Tantra of the Clear Expanse:
All samayas are explained to be contained
Concerning the samaya of enlightened form, you should not act disrespectfully towards the vajra master, the buddhas, bodhisattvas, yidam deities, dakinis, your brothers and sisters, vajra siblings, nor towards any sentient being, the five elements, or your own body. You should also refrain from taking their lives, stealing from them, abusing them physically or verbally, and so on. You shouldn’t have a distorted sense of pure view or do anything that involves nonvirtuous activities or negativity. In fact, the environment and its inhabitants, both inside and out, as well as your own body, are all divine; they are all the yidam deity. For this reason, you should have unbiased pure view towards anything associated with enlightened form, as well as make prostrations and offerings, sing their praises, and do other such things.
Concerning the samaya of enlightened speech, you should not deviate from anything that the vajra master says, nor should you belittle the Buddhist scriptures, from those of the Buddha himself down to those written by ordinary people. You should also avoid being angry or harboring malice towards any word or sound, whether it comes from the elements or a living being. Instead, act with respect and devotion, thinking of every sound as the enlightened speech of all the buddhas.
When it comes to the samaya of the enlightened mind, you should eliminate every unvirtuous thought, to the point where such thoughts do not even arise for a moment. Without breaking the continuity of virtue and bodhichitta, benefit others to the best of your ability.
As part of the samaya of enlightened form, you should meditate on the development stage of the divine yidam deity; as part of the samaya of enlightened speech, never part from the recitation of mantras; and as part of the samaya of the enlightened mind, never stray from the cycle of the completion stage.
The temporary benefits of maintaining the samaya of enlightened form in this way are that your body will be free from illness and of benefit to sentient beings. You will be pleasing to the eye, and all who touch or see you will be set on the path of virtue. Ultimately, you will arrive at the vajra seat and benefit others wherever you happen to be. Once you die, you will work for the welfare of sentient beings with an infinite number of manifestations. Your form blazing with the marks and signs, you will gain mastery over the great, enlightened activities othe buddhas and work for the welfare of others.
If the samaya of enlightened form degenerates, the temporary results will be a short life and ill-health. All sorts of undesirable things will take place and those who see or touch you will be reborn in the lower realms. Ultimately, you will experience the inescapable physical sufferings of Vajra Hell.
The temporary benefits of maintaining the samaya of enlightened speech are that your speech will be pleasing and everyone will regard what you say as the truth. As a result, gods, spirits and humans will do your bidding. You will understand the tantras, scriptures and key instructions and will be able to compose all manner of poetry and treatises, a multitude of dharma words having burst forth from your mind. All the malice and ill-will of those who listen to your speech will be pacified, all of your aims will be accomplished, and you will be liberated in one life. Ultimately, the emanations of your speech will carry out the welfare of beings and turn the wheel of the Dharma in a faultless manner.
If the samaya of enlightened speech degenerates, the temporary effects will be such that you will be in danger of contracting diseases of the tongue. Your slanderous remarks and harmful comments will harm both yourself and others, and all those who hear your words will have bad luck and be reborn in the lower realms. Ultimately, you will suffer from having five hundred ploughs run through your tongue.
The temporary benefit of maintaining the samaya of enlightened mind is that your mental emanations will tame beings. The concentration born in your own mind will naturally bring about a state of meditation in the minds of other beings. Wherever you happen to be, concentration will arise and the sentient beings in the area will be reborn in the Realm of Bliss. Ultimately, all sentient beings will be established in buddhahood and, inseparable from the vajra mind, they will transcend suffering.
If the samaya of enlightened mind degenerates, on the other hand, the temporary results will be that vice will cause harm to everyone, to both yourself and others. None of your aims will be accomplished. Instead, they will be ill-fated and illness, malicious forces and depression will beset you. Ultimately, you will have no chance to escape the lower realms.
In short, when the vows associated with the maturing empowerments are present in one’s state of being, the samaya vows need to be maintained. You should, therefore, turn away from all forms of vice and practice only virtue. In all the tantras of the Ancient Translation School, such as the Array of Samayas Tantra, the Secret Mantra’s samaya vows of the masters of awareness are taught to be of primary importance.
There are, in fact, boundless classifications of these vows, including the hundred thousand classes of samaya. The presentation here has followed that found in the texts of Heart Essence of the Dakinis, where these classifications are presented in a condensed form.