Harry Potter and the Philosopher's Stone: what age is it for? 10 alone, 9 with a parent

The codes, for parents

An orphan mistreated by his relatives learns at eleven that he is a wizard, enters a school of magic in Scotland, and finds out why everyone there knows his name.

The lexicon

• MuggleA person without magical powers, meaning everybody around you. The word recurs constantly and marks what is ordinary, sometimes with contempt.
• HogwartsThe school of witchcraft, a castle in Scotland where pupils live from eleven to seventeen. They sleep, eat and study there; parents never visit.
• The four housesOn arrival a hat sorts each pupil into Gryffindor (courage), Slytherin (ambition), Ravenclaw (intelligence) or Hufflepuff (loyalty). School life is played out in house teams, with points won and lost.
• The Sorting HatThe talking hat that sorts the pupils. It takes account of what the child asks for, which is the real subject of the scene and returns later in the series.
• QuidditchThe school sport, played on broomsticks. Two teams, several balls, and a seeker whose catch ends the match: that is the only position that matters to the story.
• Wand, spell, incantationMagic is learned like a school subject, with gestures, Latin words and bad marks. A wand chooses its wizard, which explains the scene in the shop.
• He Who Must Not Be NamedVoldemort, the dark wizard who killed Harry's parents and whom people avoid naming. Saying his name is a way of not giving in to him, and Dumbledore insists on it.
• The scarThe lightning mark on Harry's forehead, left by the attack that killed his parents. It makes him famous among wizards before he even knows magic exists.
• Diagon Alley and platform 9 3/4The crossings between the ordinary world and the magical one: a hidden street behind a pub, a platform between two platforms at King's Cross.
• The philosopher's stoneThe object everyone is after in this first film: it grants immortality. It is an old alchemical legend, not an invention of the author's.

How the world works

The magical world is hidden inside our own, in 1990s Britain: same cities, same trains, but a parallel society with its own bank, press and ministry. The school is a classic British boarding school, with uniforms, rival houses and stern teachers; many codes the film does not translate come from that, not from magic. This first film is the gentlest of the series. The tone darkens from the fourth onwards, and each film aims a little older than the last, which is why our ages differ between them.

The references

• J. K. Rowling's novel, published in 1997, was turned down by a dozen publishers before becoming the best-selling children's book in the world.
• The film was shot in real British locations, cathedrals and Oxford colleges, which is why the place feels like somewhere that exists.
• The author's public positions on transgender people mean many young readers now separate the books from the person who wrote them; if your child hears about it, the question will come.
• The film's vocabulary has left the books behind: "muggle" is in English dictionaries, the four houses are used among friends as a personality test, and platform 9 3/4 is a real tourist attraction at King's Cross station.

Why they love it

• The story opens on a child being told he is special while his family treats him as a burden: the most effective dream you can offer at that age.
• Hogwarts is a place you inhabit rather than a set: the staircases, the meals, the lessons, the forbidden corridors. Children go back to it as to a house.
• The three-way friendship, with its quarrels and reconciliations, is the real engine; the magic is only scenery around it.

Three questions to ask

• The Sorting Hat listens to what Harry asks for: does that mean you choose who you are?
• Dumbledore says it takes courage to stand up to your friends: when has that happened to you?
• Harry is famous for something he did not do and cannot remember: what must that feel like?