Gunjin Shogi (Japanese Military Chess)

Rules and how to play

The board and pieces

The board consists of 2 camps, each 6 columns wide and 4 rows deep, with a river flowing between them. The near camp belongs to the first player and the far camp to the second player. The columns are called a–f from left to right as seen by the first player, and the rows are called 1–8 starting from the first player’s back row (when you play second, the board is rotated so that your own camp is nearest to you). The river has a bridge on column b and another on column e, and the squares on both sides of the bridges (b4, e4, b5, and e5) are called entry squares. In each camp, the 2 center squares of the back row together form a single square, the Headquarters (HQ), which holds only 1 piece.^[3]

Each player has 23 pieces: 1 each of General, Lieutenant General, Major General, Colonel, Lieutenant Colonel, and Major; 2 each of Captain, First Lieutenant, and Second Lieutenant; 1 Cavalry; 2 each of Engineer, Tank, and Plane; 1 Spy; 2 Mines; and 1 Flag. A camp also has 23 squares, so once all pieces are set up, the camp is completely filled.^[3][9]

Setting up your pieces

Before the game, you place your pieces in your own camp, one to a square. You cannot see what kinds your opponent’s pieces are. Mines and the Flag cannot be placed on entry squares. The Flag also cannot be placed on the back row (including the Headquarters). A Mine can be placed in the Headquarters.

How pieces move

Once the pieces are set up, the players take turns moving 1 of their own pieces at a time, starting with the first player. You cannot pass. “Forward” means toward the opponent’s camp. Pieces move as follows.

• General, Lieutenant General, Major General, Colonel, Lieutenant Colonel, Major, Captain, First Lieutenant, Second Lieutenant, and Spy: 1 square forward, backward, left, or right.
• Tank and Cavalry: 1 square forward, backward, left, or right, or 2 squares straight forward. They can move 2 squares only when the square in between is empty.
• Engineer: any number of squares in a straight line forward, backward, left, or right. If a piece is in the way, it cannot go past that piece.
• Plane: any number of squares in a straight line forward or backward. It flies over pieces in its path (both your own and your opponent’s) and over the river. Left and right, it moves 1 square.
• Mine and Flag: cannot move.

Except for the Plane, pieces can cross the river only by a bridge. A bridge is not a square: b4 and b5 (and e4 and e5) are adjacent. A move of several squares (the Engineer, the Plane, and the 2-square move of the Tank and Cavalry) stops when it enters a Headquarters (your own or your opponent’s). From the Headquarters, a piece can move forward from either column c or column d. You cannot move onto a square occupied by your own piece.

Battles and piece strength

Moving onto a square occupied by an opponent’s piece starts a battle. In a move of several squares, the only battle is with the opponent’s piece on the destination square (a Plane does not battle the pieces it flies over). The referee compares the 2 pieces. If the attacking piece wins, the opponent’s piece is removed and the attacking piece moves onto that square. If the defending piece wins, the attacking piece is removed. If they are equal in strength, both are removed.

The movable pieces, from strongest to weakest, are the General, Lieutenant General, Major General, Plane, Tank, Colonel, Lieutenant Colonel, Major, Captain, First Lieutenant, Second Lieutenant, Cavalry, Engineer, and Spy. The stronger piece wins, and when 2 pieces of the same kind meet, both are removed. The exception is the Spy, which beats the General and only the General. The result is the same whether a piece attacks or defends.^[3]

When a Plane or an Engineer attacks a Mine, it wins, removes the Mine, and moves onto that square. Any other piece is removed together with the Mine. A Mine works only once.

The referee announces only the square where the battle took place and which side won (or that both were removed), and does not say the names of the pieces. Likewise, this page shows the names of your pieces but does not show the kinds of your opponent’s pieces until the game ends. When both pieces are removed, you cannot tell whether they were the same kind or whether one was a Mine.^[3]

How the Flag fights

The Flag fights with the same strength as the friendly piece directly behind it (on the square 1 row back toward your side). For a Flag on c2 or d2 (c7 or d7 for the second player), the piece behind it is the piece in the Headquarters. If the Flag wins with the strength of the piece behind it, the attacking piece is removed. If the attacking piece wins, only the Flag is removed, and the piece behind it stays. When the result is that both are removed, the pieces removed are the Flag and the attacking piece, and the piece behind it stays. If the piece behind it is a Mine, the Flag is judged as a Mine. If there is no friendly piece behind it, the Flag loses to every piece.^[3][9]

Winning, losing, and draws

If a General, Lieutenant General, Major General, Colonel, Lieutenant Colonel, or Major enters the opponent’s Headquarters, that player wins at that moment (occupation). It is the same whether the Headquarters was empty or the piece entered by beating the piece in it. Other pieces can also enter the Headquarters, but that does not count as occupation. A player who has no legal move when their turn comes loses. This includes the case where all of their movable pieces have been captured.

If 100 moves in a row, counting both players’ moves, are made without a battle, the game is a draw. The count starts over only on a move with a battle; a move into the opponent’s Headquarters also counts as 1 move if there is no battle. The game is also a draw when, after a move, neither player has a legal move. When the game ends, the kinds of all pieces on both sides are shown.

Rules that differ between sources

Gunjin Shogi has no fixed set of rules shared nationwide in Japan. From the Meiji era (1868–1912) to the Showa era (1926–1989), many makers sold boards and pieces, and the rules in their instructions differed slightly. In Takeshi Ichinose’s record classifying the products he owns, camps are 5–8 columns wide, and the entry points are I-, X-, or Y-shaped. The number of pieces also varied: some Meiji-era sets had 35 pieces per player, and after the Tank and the Plane were added, sets of 23 and 31 pieces became the most common. This page uses a board with 6 columns and 2 straight bridges as the entry points, and 23 pieces per player.^[1][3]

When an Engineer and a Tank battle, sources disagree on which wins. The instructions for most Japanese commercial sets from the Showa era have the Tank win, and the Engineer winning is a rule that appeared in products after pieces such as the Missile were added. Japanese Wikipedia has the Engineer win in its battle chart, but notes that in video games the Tank winning has become the de facto standard. On this page, the Tank wins.^[3][9]

Sources also differ on whether a Mine stays on the board after it wins. In the game introduced by Koda Rohan in 1900, the jiraika (地雷火, an old word for a mine) destroys itself when it explodes. The instructions of a 1996 product say that a Mine is treated as having exploded and is removed, so it can be used only once. On the other hand, many instructions say only that a Mine beats ordinary pieces, and Japanese Wikipedia lists playing without removing the Mine as a local rule. This page removes it.^[1][3][9]

As for how to win, most instructions, from Meiji-era boards to Showa-era products, call for occupying the opponent’s Headquarters. Japanese dictionaries say that the player who captures the opponent’s Flag wins, and there are also ways of playing in which defeating the opponent’s General, or capturing all of the opponent’s movable pieces, wins the game. This page counts occupation as a win and makes the player who has no legal moves left the loser.^[1][3][4][9]

Most sources agree that Mines and the Flag cannot be placed on entry squares. Placing a Mine in the Headquarters is forbidden by a book of games from 1913, and when Ichinose was a child, players followed this rule, which was passed on by word of mouth. On the other hand, the product instructions examined by Hironori Takahashi, except those with a Marshal piece, have no rule on which piece may go in the Headquarters. On this page, a Mine can be placed in the Headquarters. Japanese Wikipedia says that placing the Flag on the back row is generally prohibited, and this page does not allow it either.^[1][3][9]

Japanese Wikipedia says that the Plane can fly over pieces in its path, but Ichinose reports finding no instructions of a commercial set that state this explicitly. That the Plane moves any number of squares forward and backward and only 1 square sideways is also written in the instructions of Showa-era commercial sets. On this page, the Plane can fly over pieces and the river.^[3][9]

Controls on this page

Starting a game

Choose how to play with the buttons to the right of the board (below it on narrow screens). Press “Easy”, “Medium”, or “Hard” under “Play vs computer” to start as the first player (vermilion pieces). Press “Play second · Medium” to have the computer on Medium play first, with you as the second player (plain wood pieces). With “2 players on this device”, 2 people take turns using 1 device.

Press “Play a friend (send a link)” to create a room and show its link. Send the link to your opponent with “Copy link” (or “Share”, on devices that support it). When your opponent opens the link and presses “Join”, the game starts with the host as the first player and the player who joined as the second player. If your opponent does not come, you can switch to a game against the computer with “Play vs computer instead of waiting”. If your opponent stays disconnected for 2 minutes during a game, you can press “New game vs computer (ends this game)”. A room is deleted after 30 minutes with no one connected, or 24 hours after it was created.

Setting up your pieces

When the game starts, your pieces are placed in your camp in a random setup. Press 2 squares one after the other to swap those 2 pieces (the first square you press gets a yellow frame). A swap that would move a Mine or the Flag onto a square where it cannot go is not made, and the reason is shown.

In the panel to the right of the board (below it on narrow screens), press “Random setup” for a different setup or “Mirror” to swap left and right. “Last setup” loads the setup you confirmed last time in a game against the computer or a friend (saved in this device’s browser). When you are done, press “Confirm setup”. In a game with a friend, you can keep arranging your pieces while you wait for your opponent to join or to finish their setup. If you press “Confirm and wait” early, your setup is sent when your turn comes, and until then you can change it with “Edit setup”.

Moving pieces

On your turn, press the piece you want to move to select it, then press its destination. With a mouse or by touch, press each one once. The selected piece gets a yellow frame, empty squares it can move to show a green dot, and squares it can attack (squares with an opponent’s piece) show a red frame. The square the last-moved piece came from and its destination get an orange frame.

When a battle takes place, the result is shown, for example, “Your Lieutenant Colonel lost (c5)”. Your pieces are named, but an opponent’s piece is shown only as “the opponent’s piece”. Your own removed pieces are listed by name, while for your opponent only the number is shown. Open “Battle chart” in the panel to the right of the board (below it on narrow screens) to see which pieces each piece beats and loses to while you play.

Drag the board to rotate the view, and use the mouse wheel or a 2-finger gesture to zoom in and out. Switch views with the “Angled” and “Top-down” buttons at the top right of the board. In the “Top-down” view, the pieces are shown lying flat. When you play second, the board is rotated so that your own camp is nearest to you.

In the “Button controls” panel, the board’s squares (6 columns × 8 rows) are laid out as buttons, and you can do everything you can do on the 3D board. On a keyboard, move between squares with the arrow keys and press the Enter key to press a square. On devices where 3D display is not available, you can play with this panel alone.

Playing with 2 players on this device

At every turn, the board is hidden behind a curtain and the players switch. Only the person who presses “Start Player 1’s turn” on the curtain (or “Start Player 2’s turn” on the second player’s turn) sees the kinds of their own pieces. After moving, that person can check the battle result while the kinds of their own pieces are still shown. After checking, press “Pass the device” to bring back the curtain, and hand the device to your opponent.

During a game, you can use “Play again”, “Resign”, and “Change mode”. “Play again” is available in games against the computer and in games with 2 players on this device, and starts over from setting up the pieces. Once the game reaches the stage of moving pieces, “Undo move” no longer appears. Battle results give clues about the opponent’s pieces, so this prevents you from taking back a move after seeing them. In a game with a friend, press “Rematch (swap sides)” after a game ends to start the next one. The pieces are set up again every time.

Strategy tips

Put the General in the Headquarters, or put a Mine there and the General next to it. With the General there, you can stop occupation by the Lieutenant General or any piece below it. If only a Plane guards the Headquarters, the Headquarters becomes empty when the Plane flies off. Do not send the General forward to attack; keep it until the end.^[9]

Directly behind the Flag, place the General, the Lieutenant General, or a Mine. If a Mine is behind it, it works as if you had 1 more Mine. If the piece behind it moves or is captured, the Flag becomes weaker accordingly.^[9]

An opponent’s piece that has never moved may be a Mine or the Flag. Use the General, the Lieutenant General, and the Major General only against pieces that have moved (pieces known not to be Mines). Test pieces that have not moved with a Plane, or with a company officer (Captain, First Lieutenant, or Second Lieutenant) or the Cavalry. If your company officer or Cavalry is removed together with the opponent’s piece, that piece is the same kind or a Mine, or a Flag with a piece of the same kind or a Mine behind it (if it was the Flag, the piece behind it stays on the board).^[9]

Attacking a piece that has moved with your Lieutenant General tells you a lot. If the Lieutenant General wins, you capture that piece; if it loses, the opponent’s piece is the General. Once you know which piece is the opponent’s General, attack it with your Spy to capture it. However, if you always keep the Spy near the Lieutenant General, your opponent will notice the pattern and go after the Spy.^[9]

You can narrow down the opponent’s pieces from the pieces you lose. For example, a piece that captured your First Lieutenant is a Captain or stronger, so attacking it with a Captain will not win. How a piece moves is also a clue. A piece that moved 2 squares forward is a Tank, Cavalry, Engineer, or Plane; a piece that moved 2 or more squares sideways is an Engineer; and a piece that flew over pieces or the river is a Plane.^[9]

Conversely, if your Plane flies over a piece or your Engineer moves 2 or more squares sideways, your opponent learns its kind. Early in the game, move them 1 square at a time like other pieces. Before entering the opponent’s Headquarters, attack the piece there with a Plane or an Engineer to check that it is not a Mine.^[9]

Origin and history of Gunjin Shogi

Gunjin Shogi is a game in which pieces are set up face down, a referee compares the strength of pieces that meet, and the losing piece is removed. All pieces are the same size and have identical backs, so you cannot tell what kinds your opponent’s pieces are. Most boxes sold since the Meiji era were labeled Kogun Shogi (行軍将棋, “marching shogi”), and Gunjin Shogi spread as the common name. Japanese dictionaries also list the game under Kogun Shogi, with Gunjin Shogi and Ikusa Shogi (“war shogi”) as other names.^[1][4][5]

It is not known who devised it or when, but it was being sold and played by 1895 at the latest. The diary of Minoru Arakawa, a 10-year-old boy in Kameoka, Kyoto Prefecture, says that on October 7 of that year he went to Naito Hangetsudo to buy a Kogun Shogi set, came home, and played the game with his father, and he went on to play it with his father and friends. A photograph of a board printed in the same year also appears in the photo book Omocha Hakubutsukan (“Toy Museum”). There were also theories that the game was created around the time of the Russo-Japanese War or that it was imported from a Western game, but Takahashi rejects them on the basis of these records.^[1][2]

According to the descriptions on Meiji-era boards, each player had 35 pieces, each camp was 7 squares wide and 5 squares deep, and the 2 camps were connected by 3 straight passages. The game was played by 3 people, the 2 players plus a referee, and a player won by entering the opponent’s Headquarters. Some boards also say that when there is no referee, 2 people may play with the pieces face up. In an interview in the Yomiuri Shimbun in 1900, the writer Koda Rohan described Shidan Shogi (師団将棋), in which plain pieces of the same size had marks on their backs and a referee sat beside the players to judge.^[1][3]

The 1907 book “世界遊戯法大全” [Complete Guide to the World’s Games], in its entry on Ikusa Shogi, suggests that the game may have appeared around the time of the First Sino-Japanese War and says that no explanation is needed because it has now spread throughout the country. In January 1910, the Tokyo Asahi Shimbun reported on 3 imperial grandsons, including the future Emperor Hirohito, playing Kogun Shogi. Japanese dictionaries cite as examples of usage a line from Izumi Kyoka’s “日本橋” [Nihonbashi] (1914), “In Kogun Shogi, too, the kanja is a mighty one”, and a line from Takiji Kobayashi’s “不在地主” [Absentee Landlord] (1929), “We drew lines on paper and all played Gunjin Shogi”. Kanja is an old word for a spy.^[1][4][5]

Pieces representing the weapons of each era were added over time. Products with a Tank piece are thought to have existed in the Taisho era (1912–1926), and the boxes of later products say “Tank and Plane included”. Sets of 23 and 31 pieces became the most common. The Sekai Daihyakka Jiten says the game was popular from the late Taisho era to the early Showa era.^[1][3][4]

After the war, products with pieces such as the Atomic Bomb and the Marshal also appeared. In November 1955, the Yomiuri Shimbun reported that makers in Tendo, Yamagata Prefecture, a center of shogi piece production, were selling far more than the prewar level of about 500,000 sets a year. In June of the same year, a letter titled “Banish Kogun Shogi” appeared in the readers’ column of the Mainichi Shimbun. Products with a Missile piece were released from 1965 to 1974, and in 1976 a product with a device that judges which piece is stronger in place of a referee went on sale. The fact that the game is played by 3 people, including a referee, is given as one of the reasons it stopped being played.^[1][3]

Outside Japan, in 1905, Dr. Junghans introduced Kogun Shogi as a new Japanese war game in the German magazine Monatshefte. Its camps were 7 squares wide and 5 squares deep, with 3 straight passages and 35 pieces, the same setup as the 35-piece Kogun Shogi in Japan. The article said a player wins by occupying the headquarters or capturing the flag, and only the flag rule differs from the Japanese rules. Later, patents for similar war games were filed by Julie Berg in France and the United Kingdom in 1907, by Josephine Tilden in the United States in April 1908, and by Hermance Edan in France in November of the same year.^[1][6][7][8]

Edan’s game went on sale in 1909–1910 under the name L’Attaque, and in 1925 the British company Gibson bought the rights and began selling it. Stratego is a slightly modified version of L’Attaque made in the Netherlands, and its name was registered in 1942. In L’Attaque and Stratego, the 2 pieces are shown to both players when one attacks, and a player wins by capturing the opponent’s flag. In Gunjin Shogi, the referee judges with the pieces kept hidden, and a player wins by occupying the Headquarters.^[1][10][11]

On the relationship with similar games in Europe and the United States, Takahashi (2016) notes that all of the Western games were sold in 1909 or later and that the oldest was very likely based on the information about Japanese Kogun Shogi in the 1905 magazine, and concludes that the game originated in Japan. The French game researcher Michel Boutin also argues that Edan had a chance to learn about Gunjin Shogi, but in his conclusion he goes only so far as to write that, whatever the source of the idea, Edan indirectly brought a game from the Far East to the West. On the other hand, the historian Thierry Depaulis says that Edan filed the patent based on a game he had made in the 1880s. Neither Takahashi nor Boutin has found any record of L’Attaque before 1909.^[1][2][10]

Sources

1. Hironori Takahashi, “日本と世界の行軍将棋―軍人将棋の発祥は日本だった―” [Marching shogi in Japan and the world: Gunjin Shogi originated in Japan] (Bulletin of the Institute of Amusement Industry Studies, Osaka University of Commerce, no. 18, 2016; in Japanese) (opens in a new tab)
2. Michel Boutin, “L’Attaque, un jeu français issu du Gunjin Shogi” [L’Attaque, a French game derived from Gunjin Shogi] (in Michel Van Langendonckt [ed.], “Art et savoir de l’Inde” [Art and knowledge of India], HEB, 2015; in French) (opens in a new tab)
3. Takeshi Ichinose, “軍人将棋ルール研究” [A study of Gunjin Shogi rules] (3rd revised edition, 2014; in Japanese) (opens in a new tab)
4. Kotobank, “行軍将棋” [Kogun Shogi] (entries from Digital Daijisen, Seisenban Nihon Kokugo Daijiten, and Sekai Daihyakka Jiten [revised edition]; in Japanese) (opens in a new tab)
5. Kotobank, “軍人将棋” [Gunjin Shogi] (entry from Seisenban Nihon Kokugo Daijiten; in Japanese) (opens in a new tab)
6. Julie Berg, “Jeu de la guerre” [War game] (French Patent 379,625, 1907; in French) (opens in a new tab)
7. Josephine E. Tilden, “Game apparatus” (U.S. Patent 1,141,505, 1915) (opens in a new tab)
8. Hermance Edan, “Jeu de bataille avec pièces mobiles sur damier” [Battle game with movable pieces on a checkerboard] (French Patent 396,795, 1909; in French) (opens in a new tab)
9. Wikipedia (Japanese), “軍人将棋” [Gunjin Shogi] (opens in a new tab)
10. Wikipedia (English), “L’Attaque” (opens in a new tab)
11. Wikipedia (English), “Stratego” (opens in a new tab)

Frequently asked questions

When did Gunjin Shogi first appear?

No one knows who devised it, but it was being sold and played by 1895 at the latest. A diary records that in October of that year, a 10-year-old boy in Kameoka, Kyoto Prefecture, went to a shop to buy it and played it with his father after coming home. Later, pieces representing the weapons of each era, such as the Tank and the Plane, were added, and the game was popular from the late Taisho era to the early Showa era.

Which pieces can beat the General?

Only the Spy. The Spy wins both when it attacks the General and when the General attacks it. Every other movable piece loses to the General, and when 2 Generals meet, both are removed. When the General attacks a Mine, both are also removed. The Flag fights with the same strength as the piece behind it, so if the General attacks a Flag with the Spy behind it, the General is removed.

Which wins, the Engineer or the Tank?

On this page, the Tank wins. The instructions for most Showa-era Japanese commercial sets also have the Tank win. The Engineer winning is a rule that appeared in products after pieces such as the Missile were added, and the battle chart on Japanese Wikipedia also has the Engineer win. You can check which piece wins each battle on this page in the “Battle chart” to the right of the board (below it on narrow screens).

Do you lose if your General is captured?

No. The winner is decided by whether a player occupies the opponent’s Headquarters with a General, Lieutenant General, Major General, Colonel, Lieutenant Colonel, or Major. Losing all 6 of these kinds doesn’t by itself make you lose, but since you no longer have any piece that can occupy, you can no longer win by occupation. A player who has no legal move when their turn comes loses.

Can your opponent see what kinds your pieces are?

No. In games with a friend, the game server judges battles, and your opponent’s screen receives only a view with the kinds of your pieces hidden. The only things announced are the square where a battle took place and the result (which side won, or that both were removed). In games against the computer, too, the computer doesn’t look at the kinds of your pieces; it plays by guessing from how your pieces move and from battle results. When the game ends, the kinds of all pieces on both sides are shown.

When does a game end in a draw?

A game is a draw when 100 moves in a row, counting both players’ moves, are made without a battle, and when neither player has a legal move after a move (for example, when the last movable pieces on both sides are removed together). Whenever there is a battle, the count starts over from 0. There’s no fixed rule for a deadlocked game, and it varies by region, so this page sets the limit at 100 moves.

Can you play without a referee?

Yes. In the past, the game was played by 3 people, the 2 players plus a referee, and the referee compared the 2 pieces to decide which won. On this page, the program in your browser acts as the referee in games against the computer and with 2 players on this device, and the game server does so in games with a friend. With 2 players on this device, the board is hidden behind a curtain at each turn, and only the player whose turn it is sees the kinds of their own pieces.

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