PURPOSE: To provide a game apparatus, wherein the state of progress of a game can be inputted into a computer without imposing a burdon on a player, and instructions from the computer to the player are effected with ease.

CONSTITUTION: In an instruction input-output apparatus 1 are arranged a board 11 for shogi (Japanese chess) including a check pattern and check patterns 12, 13 where captured chessmen are positioned. A processor 2 such as a computer processes the input from the apparatus 1 and sends the processed results to the apparatus 1. Each chessman has a magnet 31 embedded in the center thereof, and the top side of the magnet 31 is N-poled while the bottom side thereof is S- poled. In case check of the board 11 a magnetosensitive element 14 is embedded and lamps 15 are also embedded at upper left corner and lower right corner of the element 14. The magnetosensitive element 14 is connected to a power source 141, and when electric current is passed to the element from the power source 141, the output of an output terminal 142 varys according to the strength of the influenced magnetic field of the electromagnetic element 14, and the polarity of said output also verys according to the direction of the magnetic field. Using said output it is detected whether there is a chessman on a check or not and whether the chessman is in the heat or tail if there is a chessman on the check. If a chessman is moved it is detected and the corresponding instruction is indicated by the lamp 15.