who rules if the king is too young
Regency Acts According to the Regency Acts in force, if the monarch is under the age of 18 years when he or she succeeds to the Throne, a regency is automatically established, and, until the monarch attains the age of 18 years, the royal functions are discharged by the regent in the name and on behalf of the monarch.
King (chess) A king can move one square in any direction (horizontally, vertically, or diagonally) unless the square is already occupied by a friendly piece or the move would place the king in check. As a result, the opposing kings may never occupy adjacent squares (see opposition), but the king can give discovered check by unmasking a bishop, rook, or queen. The king is also involved in the special move of castling.