The Big Doll House

Jack Hill and Roger Corman more or less invent the modern women-in-prison film in the Philippines, cheap and fast, with Pam Grier in an early role and a formula that four hundred films would copy: the newcomer, the sadistic warden, the shower, the riot, the break.

It is exploitation with no pretensions and a surprising amount of energy, and Hill directs it with more competence than the budget deserved. Grier also sings the theme, badly and enjoyably.

The template, if not the best example of it.