Bugang is a Daoist ritual dance or walk, based upon the Yubu "Steps of Yu" tradition, in which a Taoist priest paces through a supernatural pattern, such as stars in the Big Dipper or numbers in the Loshu magic square. Texts from the (4th century) Shangqing School revelations contain the earliest descriptions of bugang, frequently with the practitioner pacing among constellations, especially the Big Dipper's stars. When religious Daoism began during the Six Dynasties period (220–589 CE), the expression bugang tadou 步罡踏斗 "pacing the guideline and treading on (the stars of) the Dipper" became popular.