The king moves one square in any direction — horizontally, vertically, or diagonally. Because it can only step a single square at a time, the king is slow but always active. It can never move into check, meaning it cannot land on a square attacked by an enemy piece, and the two kings can never stand next to each other. The king also takes part in castling, its only move that covers more than one square. Protecting the king is the whole point of chess: if it is checkmated, the game ends. Keep it safe early, then use it as a fighting piece in the endgame.