Most important religious ritual of the Plains Indians of North America. Ordinarily held by each tribe once a year in early summer, it is simultaneously an opportunity to reaffirm basic beliefs about the universe and the supernatural through rituals and a highly sacred event through which personal sacrifice is undertaken for the general well-being of the community and the individual. The ritual originated long ago and has been widely adopted by indigenous Plains peoples from Saskatchewan, Can., to Texas, U.S. The central rite involves male supplicants who, in order to fulfill a vow, to seek spiritual energy and insight, and for the health of the community, pledge to dance for several days without stopping for food, drink, or sleep, their ordeal ending in exhaustion. Among some tribes, piercing and sun gazing are practiced.