It is a misconception that most of the film was improvised by the actors. Jacques Rivette provided structure but did not let his actors "go wild", instead he let them write. A single scene was improvised, where Celine, played by Julie Berto, brags to her associates about her rich American friend. The rest of the scenes where shot from scripted material, mostly thanks to participating actors. The film is collaboration by several authors, including actors Berto, Labourier, Ogier and Pisier. Rivette's involvement in the writing was to give structure to all the contributions, tightening things up.
Ranked number 81 non-English-speaking film in the critics' poll conducted by the BBC in 2018.
Drawn on a blackboard in Julie's room is a magic square. Each line, column and main diagonal add up to 34. Magic squares were widely used by mystics, alchemists and occultists since at least 400 CE and therefore would be something that would interest Julie, who is seen reading a book about magic and consulting tarot cards.
David Thomson, the acclaimed film critic, has said that this is his all-time favorite film.
This film is part of the Criterion Collection, spine #1,069.