Chinese folk cosmology holds that for the entirety of the seventh lunar month, popularly called Ghost Month, the gates separating the underworld from the world of the living stand open, allowing spirits of every kind to wander freely among the living before the gates close again at month's end. The fifteenth day, the full moon at the month's midpoint, is treated as the peak of this period and is marked by Zhongyuan Jie, the primary set of communal and household observances. The spirits of greatest concern are hungry ghosts, egui, souls who died without descendants to maintain their ancestor cult, died violently or improperly, or were simply forgotten, and who are believed to wander in a state of perpetual hunger and deprivation, capable of causing illness, accidents or general misfortune to the living out of desperation or resentment rather than deliberate malice in most accounts.
Unlike the household ancestor cult, which is a family's private obligation to its own dead, the Ghost Festival is explicitly communal, since these unattended spirits by definition have no family of their own to feed them, making their placation a shared responsibility of the wider community, temples and neighborhoods rather than any single household.