Maha Yoga

Skt., mahayoga
Tib., rNal-'Byor Ch'en-Po

Also known as Father Tantras (Tib., pha-rgyud, Skt., pitryoga) outside the Nyingma tradition,
Maha Yoga belongs to the Inner Tantras and constitutes level 7 of the Nine Vehicles

These are teachings that mainly concentrate on the generation process (Tib., bskyed-rim), i.e. the creative stage that corresponds to method. There is an emphasis on "skillful means" (Skt., upaya) and on the use of elaborate mandalas.

Major text:
Guhyagarbha (Tib., gSang-ba snying-po), "The Secret Heart" or "Essence of Secrets"