This is the fifth screen version of Louis Pergaud’s 1912 novel, about a children’s game that gets out of hand, and as far as I can tell it’s the first to transplant his story to the French occupation. The title refers to an escalating feud between schoolboy gangs in a bucolic village; captured combatants get all the buttons cut off their clothes and have to walk home holding their pants up. Director Christophe Barratier (The Chorus) pitches this story line like an Our Gang comedy (one little warrior is a mugging, bespectacled tyke who wears a colander for a helmet) and grafts onto it a grown-up tale, draped in a syrupy score, about a Jewish child being sheltered from the Nazis by a local woman (Laetitia Casta) and the handsome schoolteacher who loves her (Guillaume Canet). In French with subtitles.