Trivia

The famous director Truffaut attacked René Clément as he was stopping the growth of film as art. “Clément behaved like the pseudo intellectuals with which the French cinema is overpopulated, half educated scholars for whom the height of genius is to remove from art anything that comes from the heart.”
--Source: The films in my life, Page 199

Director Clément found inspiration for his lifelong interest in the effect of war on children while making his film The Walls of Malapaga (1948). He asked a young girl performing in a scene in that film why she acted with her hand in her pocket. The crying child then withdrew a misshapen hand that had been badly injured during the war.

The film was initially planned as one chapter in a three-part anthology film about childhood. But halfway through the production, Clément realized the story would be perfectly suited to a full-length film and so abandoned the notion. Unfortunately Brigitte Fossey had lost her milk teeth and Georges Poujouly had had his hair cut. So, in many scenes of the movie Paulette has false teeth and Michel is wearing a wig.

The film is based on Francois Boyer's novel Les Jeux Inconnus