Classification of Buddhist Tantras

Traleg Kyabgon Rinpoche's Essence of Buddhism includes Levels of Tantra (138) from a Kagyu point of view:

Levels of Tantra

Vajrayana practices, or tantric teachings, have been systematized into four categories, and practitioners are encouraged to follow them in a systematic and gradual way. The relationship that exists between the visualized deities and the practitioner will go through different transitions, depending upon the level of Tantra with which the person engages. Even the natures of the visualized deities are different; they may be wrathful or peaceful, for example.

Kriya Tantra

The first level of Tantra is Kriya Tantra, or bya gyü in Tibetan. Kriya emphasizes the performance of rituals. Three different Buddha families are mentioned at the Kriya tantric level: the Padma, or Lotus family; the Vajra family; and the Tathagathas or family of the Buddhas. At this level, the relationship between practitioner and deity is essentially unequal. We see ourselves as being deluded, while the deity is worshipped as having all the power to impart wisdom.

Charya Tantra

The next stage is Charya Tantra, or chö gyu. Charya emphasizes the importance of both meditative states and ritual observances. At that level, there is no longer the same sense of inequality as with Kriya Tantra. The deities are seen as friends more than exalted beings, even while having little in common with the practitioner in terms of qualities. At that Charya level, deities are visualized as having two aspects, relative and absolute. The absolute nature of visualized deities is understood to be no different from one's own Buddha-nature, or the nature of Mind. The basic point is that the visualizations are not absolute since they are understood as projections of the mind.

Anuyoga Tantra

The next level is Anuyoga Tantra, or jesu naljor gyü. Here one relies less and less on relative truth and aims towards absolute truth. At the Anuyoga level, it is said that one must have developed bodhichitta and taken the Bodhisattva vow, for without it one cannot continue the practice. Anuyoga deals with delusions and defilements directly, so that they can be transformed into the Five Wisdoms.

When understood properly, these very delusions can be transformed into wisdom, and therefore the delusions are the very material that constitutes what is meant by wisdom. There is no sharp distinction between what should be abandoned and what should be cultivated at this stage. If one knows how to deal with things that normally give rise to delusions, one can gain insight and wisdom instead

Supreme Yoga Tantra: Becoming a Total Person

The final level of Tantra is Mah'anuttarayoga Tantra, or la-me chenpo'i gyü, is considered to be the supreme level. It is also the most difficult one to practice. Unlike the other Tantras, on this level the practitioner deals directly with his or her conflicting emotions through practices such as the visualization of wrathful deities ... .

~ edited from LM's messages to the Kagyu email list.

Anuttarayoga Tantras are classified as either Mother, Father or Non-dual

Father Tantra [comprises]: Anuttarayoga Tantra practices utilizing mainly aggression as the path, focusing on the emptiness aspect of Buddhanature. Examples of Father Tantras include Guhyasamaja and Yamantanka, as well as the practices of "illusory body" and of dream yoga.

Mother Tantra: Anuttarayoga Tantra which utilize desire as the path, focus on the luminosity of Buddha-nature. Examples include Chakrasamvara, tummo [heat/energy generation], and clear light yoga.

Non-dual Tantra: Anuttarayoga Tantra practices utilizing equally, desire and anger, act as an antidote to the 3rd poison which is ignorance. They place equal focus on the luminosity and emptiness aspects of Buddha-nature. Examples include Kalachakra, Hevajra and the yoga of the Bardo.

So, for example, if you are a person with a short fuse, who gets angry all the time, it is sometimes beneficial to take advantage of that "natural" propensity by pursuing the Father Tantras. Then, in some of the illusory body practices, ... , you don't have to exert yourself too much to gain accomplishments.

When it gets to the top [advanced tantras] however, there is little if any difference between taking the aggression path versus taking the passion path -- it is all the same: non-duality of luminosity and emptiness.

--khandro.net