Chu shogi

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Chū shōgi (中将棋 'middle chess') is a board game native to Japan. It is similar to modern shogi (sometimes called Japanese chess) in its rules and game play. Its name means "mid-sized shogi", from a time when there were three sizes of shogi variants in regular use. Chu shogi seems to have been developed in the early 14th century as a derivative of dai shogi ("large shogi"). There are earlier references, but it is not clear that they refer to the game as we now know it. With fewer pieces than dai shogi, the game was considered more exciting. It was still commonly played in Japan in the early 20th century, especially in Kyoto, but now has largely died out. It has, however, gained some adherents in the West. The main reference work in English is the Middle Shogi Manual by George Hodges.

[edit] Rules of the game

[edit] Objective

The objective of the game is to capture the opponent's king and, if present, the crown prince, which counts as a second king; or to capture all the other pieces, leaving a bare king or a bare crown prince. Unlike standard shogi, pieces may not be dropped back into play after capture.

[edit] Game play

Two players alternate making a move, with Black moving first. (The pieces are not differentiated by color; the traditional chess terms "Black" and "White" are only used to indicate who plays first, and to differentiate the sides during discussions of the game.) A move consists of moving a piece either to an empty square on the board or to a square occupied by an opposing piece, thus capturing that piece; and optionally of promoting the moving piece, if all or part of its move lies in the promotion zone.

[edit] Game equipment

Two players, Black and White (or 先手 sente and 後手 gote), play on a board ruled into a grid of 12 ranks (rows) and 12 files (columns). The squares are undifferentiated by marking or color, unlike a Western chess board.

Each player has a set of 46 pieces of 21 different types, and each piece has its name written on it in Japanese kanji. The writing is typically in black. On the reverse side of most pieces there are characters to indicate the piece's promoted rank, typically written in red. The pieces are wedge-shaped and their orientation indicates which player they belong to, as they point toward the opposing side. The pieces are of slightly different sizes, from largest to smallest (most to least powerful) they are:

Initial setup with the full name in kanji on each piece.

• 1 King
• 1 Free king
• 1 Lion
• 2 Dragon kings
• 2 Dragon horses
• 2 Rooks
• 2 Bishops
• 1 Kirin
• 1 Phoenix
• 1 Drunk elephant
• 2 Blind tigers
• 2 Ferocious leopards
• 2 Gold generals
• 2 Silver generals
• 2 Copper generals
• 2 Vertical movers
• 2 Side movers
• 2 Reverse Chariots
• 2 Lances
• 2 Go-betweens
• 12 Pawns

[edit] Table of pieces

Listed below are the pieces of the game and, if they promote, the pieces they promote to. Names are rough translations that have become somewhat standardized in English. Pieces are listed alphabetically by their English name.

The promotions apply only to pieces which start out with the ranks in the left-most column, that is, pieces with these ranks written in black; promoted pieces with those same ranks written in red may not promote further. Pieces which only appear upon promotion, that is, names which only occur written in red, are marked with an asterisk. The king, free king, and lion do not promote.

¹ The names of 龍馬, 奔王, 反車, and 白駒 are irregular. The regular forms ryūme, hon’ō, hansha, and hakuku are also seen.

² In many accounts of chu shogi, a pawn is described as promoting to gold; the special name tokin for a promoted pawn is in these descriptions restricted to standard shogi. Note that this is simply a naming convention and makes no difference in the movement of the piece.

[edit] Setup

Below is a diagram showing the setup of the players’ pieces. The board setup is symmetrical: the way one player sees their own pieces is the same way that the opposing player sees their pieces.

Chu Shogi setup. For legibility, the names of most pieces are abbreviated to a single kanji in this image. In real game sets, the full piece names are normally used, as shown below.

[edit] Promotion

Promoted values, corresponding to the board setup above

The promotion zone is the 'enemy camp', the farthest four ranks of the board, which are mostly occupied by the opposing player's pieces when the board is first set up. When a promotable piece makes a move within the promotion zone—including entering, leaving, or moving entirely within the zone,—it has the option of "promoting" to a more powerful rank. Promotion is effected by turning the piece over after it moves, revealing the name of its promoted rank. Promotion is not mandatory if the unpromoted piece could move further on a later turn, and in some cases it may be beneficial to leave the piece unpromoted. Promotion is permanent and promoted pieces may not revert to their original rank. If a piece is not promoted upon entering the promotion zone, then it may not promote on the next turn unless it makes a capture, with the exception of pawns: If a pawn does not promote once entering the promotion zone, then it may not promote until it reaches the farthest rank.

Promoting a piece has the effect of changing how that piece moves. See below.

If a pawn or lance reaches the furthest rank, it must promote, since it would otherwise have no legal move on subsequent turns.

[edit] Piece movement

An opposing piece is captured by displacement: That is, if a piece moves to a square occupied by an opposing piece, the opposing piece is displaced and removed from the board. A piece cannot move to a square occupied by a friendly piece, that is, by another piece controlled by the moving player.

Each piece on the game moves in a characteristic pattern. Pieces move either orthogonally (that is, forward, backward, left, or right, in the direction of one of the arms of a plus sign, +), or diagonally (in the direction of one of the arms of a multiplication sign, ×). The lion is the sole exception, in that it is not required to move in a straight line.

As stated earlier, this game is based on dai shogi and all of the pieces of this game can be found in dai shogi. The eight types of pieces that where removed all promoted to gold generals, which made for comparatively dull game play.

If a pawn or lance, which cannot retreat or move aside, advances across the board until it reaches the other side, it must promote.

Many pieces are capable of several kinds of movement, with the type of movement most often depending on the direction in which they move. The movement categories are:

[edit] Step movers

Some pieces move only one square at a time. If a friendly piece occupies an adjacent square, the moving piece may not move in that direction; if an opposing piece is there, it may be displaced and captured.

The step movers are the king, drunk elephant, blind tigers, ferocious leopards, the generals, go-betweens, and the 12 pawns of each side. Only the king can potentially move in all eight directions.

[edit] Jumping pieces

Several pieces can jump, that is, they can pass over any intervening piece, whether friend or foe, with no effect on either. These are the lion, the kirin, and the phoenix. Only the lion can jump in all directions.

[edit] Ranging pieces

Many pieces can move any number of empty squares along a straight orthogonal or diagonal line, limited only by the edge of the board. If an opposing piece intervenes, it may be captured by moving to that square and removing it from the board. A ranging piece must stop where it captures, and cannot bypass a piece that is in its way. If a friendly piece intervenes, the moving piece is limited to a distance that stops short of the intervening piece; if the friendly piece is adjacent, it cannot move in that direction at all.

The ranging pieces are the free king, dragon king, dragon horse, rook, bishop, vertical mover, side mover, reverse chariot, and lance. Only the free king can range along all eight directions.

[edit] Lion move (multiple capture)

The lion has a sequential multiple-capture ability, called a 'lion move', as do the soaring eagle and horned falcon (promoted dragon king and dragon horse) to a lesser extent. The details of these powerful moves are described for the lion below.

[edit] Individual pieces

Following are diagrams that indicate the movement of each piece. Pieces are listed roughly in order, from front to back rows, with pieces making similar moves paired. Pieces with a grey heading start out in the game; those with a blue heading only appear on the board as a promoted piece.

The next three pieces have special movements that involve the ability to move and even capture twice per turn.

[edit] Check and mate

When a player makes a move such that the opponent's only remaining royal (king or crown prince) could be captured on the following move, the move is said to give check; the king or crown prince is said to be in check. If a player's king or crown prince is in check and no legal move by that player will get it out of check, the checking move is also mate, and effectively wins the game.

Unlike Western chess, a player need not move out of check in chu shogi, and indeed may even move into check. Although obviously not often a good idea, a player with more than one royal may occasionally sacrifice one of these pieces as part of a gambit.

A player is not allowed to give perpetual check.

[edit] Game end

A player who captures the opponent's sole remaining king or crown prince wins the game. In practice this rarely happens, as a player will resign when checkmated, as otherwise when loss is inevitable.

A player who has only one piece left (a bare king or bare crown prince) loses unless he can bare or mate his opponent in the next move.

A player who makes an illegal move loses immediately. (This rule may be relaxed in casual games.)

There are two other possible (but fairly uncommon) ways for a game to end: repetition (sennichite) and impasse (持将棋, jishōgi).

If the same position occurs four times with the same player to play, then the game is no contest. (Recall, however, the prohibition against perpetual check.)

The game reaches an impasse if both kings or crown princes have advanced into their respective promotion zones and neither player can hope to mate the other or to gain any further material.

[edit] Game notation

The method used in English-language texts to express shogi moves was established by George Hodges in 1976. It is derived from the algebraic notation used for chess, but modifications have been made for chu shogi.

A typical example is P-8f. The first letter represents the piece moved (see setup above). Promoted pieces have a + added in front of the letter, for example +P for a tokin (promoted pawn). The designation of the piece is followed by a symbol indicating the type of move: - for an ordinary move or x for a capture. Next is the designation for the square on which the piece lands. This consists of a number representing the file and a lowercase letter representing the rank, with 1a being the top right corner (as seen from Black's point of view) and 12l being the bottom left corner. (This method of designating squares is based on Japanese convention, which, however, uses Japanese numerals instead of letters. For example, the square 2c is denoted by 2三 in Japanese.)

If a move entitles the player to promote the piece, then a + is added to the end to signify that the promotion was taken, or an = to indicate that it was declined. For example, PX7d= indicates a pawn capturing on 7d without promoting.

In cases where the above notation would be ambiguous, the designation of the start square is added after the designation for the piece in order to make clear which piece is meant.

When a 'Lion', 'Horned Falcon' or 'Soaring Eagle' captures by 'igui' (that is, without moving), the square of the piece being captured is used instead of the destination square, and this is preceded by the symbol '!'. For example, a Lion on 8c capturing a piece on 9d would be shown as LNx!9d.

When a piece makes a double capture with 'Lion' powers both captures are shown in the order that they were made. For example, a Lion on 3g, capturing a piece on 3h and then capturing another on 2i, would be represented by LNx3hx2i.

Moves are commonly numbered as in chess.

[edit] See also

• Shogi variant
• Wa shogi
• Heian dai shogi
• Dai shogi
• Tenjiku shogi
• Dai dai shogi
• Maka dai dai shogi
• Tai Shogi
• Taikyoku shogi

[edit] External links

• Chu Shogi page

• Chu Shogi strategy etc.

• German Chu Shogi Association (GCSA) with many reports and games to replay online