Harry Potter’s game of chess

Novice chess players can seem spellbound by the power of their own queen, zigzagging hither and thither in desperate search of bounty. You soon learn that on the chessboard strength is weakness and weakness is strength; the queen must flee from any attack while a pawn is, well, only a pawn in your game. Experienced players acquire a more mercantile approach – every piece has its price. In fact, being ready to dispense with an ostensibly valuable piece in service of a higher goal is the mark of a skilful player.

Making great play of this is the chess game from Harry Potter and the Philosopher’s Stone, presumably one of the most widely viewed chess scenes in cinema history. The American international master Jeremy Silman, who died aged 69 in Los Angeles last week, devised the sequence which begins at the diagram below.

On their quest, Harry, Ron and Hermione become embroiled in a game of wizard’s chess. The intrepid trio take their places as a bishop, knight and rook respectively on a giant chess board. This is a hazardous undertaking, since their fellow combatants are stout warriors carved from stone, which execute their captures with all the finesse of a wrecking ball. Naturally, it is crucial that Harry is kept alive.

Harry is the bishop on a3, Ron the knight on g5 and Hermione the rook on f8. The white queen is the villain, who captures 1 Qxd3, bearing down on Harry, while simultaneously guarding against Ng5-h3+. Fortunately, Ron is a strong player, and the next move is brilliant: 1…Rc3!! inviting another demolition job from the white queen. 2 Qxc3 crashes closer to Harry and sets up the climax. In pure chess terms, 2…Bc5+ 3 Qxc5 Nh3 would be mate. The snag is that Harry is not expendable. Ron knows this, so he performs the ultimate act of chivalry in the service of his friend: 2… Nh3+ 3 Qxh3 leaves Ron unhorsed and motionless on the ground (spoiler: he survives), allowing Harry to deliver the coup de grâce: 3…Bc5+ 4 Qe3 Bxe3 mate.