Wizard Chess Knight
Brilliant Trapdoor Chamber
Underground Chamber, Hogwarts Castle
The fourth obstacle protecting the Philosopher's Stone was a life-sized game of wizards chess. In order to proceed through the underground chamber, one had to take the place of one of the chess pieces and win the game. Harry Potter assumed the role of a bishop, Hermione Granger played as a castle, and Ron Weasley functioned as both a knight and the game's commander. In the end, Ron valiantly sacrificed himself to the white queen so Harry could checkmate the king.