"Nunsploitation is a subgenre of exploitation film which had its peak in Europe in the 1970s. These films typically involve Christian nuns living in convents during the Middle Ages. The main conflict of the story is usually of a religious or sexual nature, such as religious oppression or sexual suppression due to living in celibacy. The Inquisition is another common theme. These films, although often seen as pure exploitation films, often contain criticism against religion in general and the Catholic church in particular. Indeed, some protagonist dialogue voiced feminist consciousness and rejection of their subordinated social role. Many of these films were made in countries where the Catholic Church is influential, such as Italy and Spain. One atypical example of the genre, however, is Killer Nun (Suor Omicidi), set in, then, present-day Italy (1978).
Nunsploitation, along with Nazisploitation, is a subgenre that ran a parallel course alongside Women in prison films in the 1970s and 1980s. As with prison films, they are set in isolated, fortress-like convents where the all-female population turns to lesbianism and perversity. The element of religious guilt allows for lurid depictions of "mortifying the flesh" such as self-flagellation and painful, masochistic rituals. The Mother Superior is usually a cruel and corrupt warden-like martinet who enforces strict discipline (more opportunities for whippings and medieval-style punishments) and often lusts after her female charges. An equally sadistic and lecherous priest is often included to add an element of masculine menace to the story. (Wikipedia)