The Bardo Thodol, commonly known in the West as The Tibetan Book of the Dead, is a terma text from a larger corpus of teachings, the Profound Dharma of Self-Liberation through the Intention of the Peaceful and Wrathful Ones, revealed by Karma Lingpa (1326–1386). It is the best-known work of Nyingma literature. In 1927 the text was one of the first examples of both Tibetan and Vajrayana literature to be translated into a European language and arguably continues to this day to be the best known.

Tertön is a term within Tibetan Buddhism meaning a person who is a discoverer of ancient hidden texts or terma. Many tertöns are considered to be incarnations of the twenty five main disciples of Padmasambhava, who foresaw a dark time in Tibet. He and his consort Yeshe Tsogyal hid teachings to be found in the future to benefit beings. A vast system of transmission lineages developed. Scriptures from the Nyingma school were updated by terma discoveries, and terma teachings have guided many Tibetan Bon and Buddhist practitioners.