A ganacakra ( Sanskrit: gaṇacakra "gathering circle"; ) is also known as tsog, ganapuja, cakrapuja or ganacakrapuja. It is a generic term for various tantric assemblies or feasts, in which practitioners meet to chant mantra, enact mudra, make votive offerings and practice various tantric rituals as part of a sādhanā, or spiritual practice. The ganachakra often comprises a sacramental meal and festivities such as dancing; the feast generally consisting of materials that were considered forbidden or taboo in medieval India, where the tantric movement arose. As a tantric practice, forms of gaṇacakra are practiced today in Hinduism, Bön and Vajrayāna Buddhism.
Professor Miranda Shaw summarises the experience of a gaṇacakra:The feast is an esoteric ritual that unfolds in many stages. The sacred space for the ceremony is demarcated by geometric designs drawn on the ground with powdered pigments, and an elaborate array of offerings and foods are laid out. The participants don special insignia like bone ornaments and crowns and use musical instruments of archaic design... for inducing heightened awareness. Practitioners sit in a circle and partake of sacramental (dry) meat and wine (often liquor) served in skull-cups.The feasts also provide an occasion for the exchange of ritual lore, the ritual worship of women (sripuja), and the performance of sexual yogas. The feast culminates in the performance of tantric dances and music that must never be disclosed to outsiders. The revelers may also improvise " songs of realization" (caryagiti) to express their heightened clarity and blissful raptures in spontaneous verse.
Samual holds that:[S]erious Tantric practice is generally seen as appropriate for a small minority only. The ancient Indian , the circle ritual...discussed earlier, is far in the past. In Tibetan practice it has long been replaced by the (Tibetan: tshogs), a considerably tamer affair, still involving a sacramental meal but normally performed indoors and without possession or dancing.