Shogi: Encyclopedia II - Shogi - Rules of the game

Shogi - Rules of the game

Shogi - Objective

The objective is to checkmate your opponent's king.

Shogi - Game equipment

Two players, Black and White (or sente and gote), play on a board composed of squares in a grid of 9 ranks (rows) by 9 files (columns). The squares are undifferentiated by marking or colour.

Each player has a set of 20 wedge-shaped pieces, of slightly different sizes. From largest to smallest (most to least powerful) they are:

• 1 king
• 1 rook
• 1 bishop
• 2 gold generals
• 2 silver generals
• 2 knights
• 2 lances
• 9 pawns

Most of these names are chosen to correspond to their rough equivalents in Western chess and not as literal translations of the Japanese names.

Each piece has its name marked on its surface in the form of two kanji, usually in black ink. On the reverse side of each piece, other than the king and gold general, are one or two other characters, often in a different colour (usually red); this reverse side is used to indicate that the piece has been promoted during play. The pieces of the two players do not differ in colour, but instead each piece is shaped like a wedge, and faces forward, toward the opposing side. This shows who controls the piece during play. See Shogi Pieces and Symbols for pictures of the pieces, both normal and promoted.

The Chinese characters (kanji) have deterred many people who are not familiar with them from learning shogi. This has led to the development of "Westernized" (or "international") pieces, which replace the characters with intuitive symbols. However, partially because the traditional pieces are iconic by size, with more powerful pieces being larger, most players soon learn to recognize them, and Westernized pieces have never become popular.

Here is a table of the pieces with their Japanese representation. The abbreviations are used both for game notation and in several cases, to refer to the pieces in speech.

* 竜 is a simplified form of 龍.

English speakers sometimes refer to promoted bishops as horses and promoted rooks as dragons, after their Japanese names, and generally use the Japanese name tokin for promoted pawns. Silver generals and gold generals are commonly referred to simply as silvers and golds.

The characters inscribed on the reverse sides of the pieces to indicate promoted rank may be in red ink, and are usually cursive. The characters on the backs of the pieces that promote to gold generals are cursive versions of 金 'gold', becoming more cursive (more abbreviated) as the value of the original piece decreases. The cursive characters have these equivalents in print: 全 for promoted silver, 今 for promoted knight, 仝 for promoted lance, and 个 for promoted pawn (tokin). Another convention has abbreviated versions of the unpromoted ranks, with a reduced number of strokes: 圭 for promoted knight, 杏 for promoted lance, the same 全 as above for promoted silver, and と for tokin.

Shogi - Rankings

[1]

Shogi - Setup

Each player places his pieces in the positions shown below, pointing toward the opponent.

• In the rank nearest the player:
  • The king is placed in the center file.
  • The two gold generals are placed in the adjacent files to the king.
  • The two silver generals are placed adjacent to each gold general.
  • The two knights are placed adjacent to each silver general.
  • The two lances are placed in the corners, adjacent to each knight.

That is, the first rank is |L|N|S|G|K|G|S|N|L|.

• In the second rank, each player places:
  • The bishop on the player's left in the same file as the knight.
  • The rook on the player's right in the same file as the knight.
• In the third rank, the nine pawns are placed one to each file.

Traditionally, even the order of placing the pieces on the board is determined. There are two recognized orders, ohashi and ito. Shogi Pineapple indicates the order (page is in Japanese); ohashi is depicted on the left and ito on the right.

Shogi - Gameplay

The players alternate taking turns, with Black playing first. (The traditional terms 'black' and 'white' are used to differentiate the sides during discussion of the game, but no longer refer to the colors of the pieces.) A 'play' may be one of two things: A 'move', where a player slides a piece across the board and potentially promotes; or a 'drop', where a captured piece is placed onto an empty square of the board. Each of these options is detailed below.

Professional games are played with a timer, as they are in International Chess.

Shogi - Movement and capture

Each piece moves in a distinct manner. The king, generals, and pawns move a single square at a time. If an opponent's piece occupies a possible destination, it may be captured by sliding the moving piece to that square and removing the opposing piece from the board. If a friendly piece (that is, a piece controlled by the moving player) occupies the square, the player may not move in that direction.

The knight jumps, that is, it passes over any intervening piece, whether friend or foe, without any effect on either. It is the only piece that can do this.

The lance, bishop, and rook can potentially move any number of squares along a straight line limited by the edge of the board. If an opponent's piece intervenes, it may be captured by moving to that square, and removing it from the board. 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 may not move in that direction at all.

Pieces move either orthogonally (that is, forward, backward, or to the side, 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 knight is the only exception.

A king can move one square in any direction, orthogonal or diagonal.

A gold general can move one square orthogonally, or one square diagonally forward, giving it six possible destinations. It cannot move diagonally backward.

A silver general can move one square diagonally or one square directly forward, giving it five possibilities.

Because an unpromoted silver can retreat more easily than a promoted one (see below), it is very common to leave a silver unpromoted at the far side of the board.

A knight jumps at an angle intermediate between orthogonal and diagonal, amounting to one square forward plus one square diagonally forward, in a single motion. That is, it has a choice of two forward destinations. It cannot move to the sides or backwards.

The knight is the only piece that ignores intervening pieces on the way to its destination, though its destination square must of course be either empty, or occupied by an opponent's piece (in which case the opponent's piece is captured), just as with any other moving piece.

It is often useful to leave a knight unpromoted (see below) at the far side of the board. However, since a knight cannot move backward or to the sides, it must promote when it lands on one of the two farthest ranks and would otherwise be unable to move further.

A lance can move any number of free squares directly forward. It cannot move backward or to the sides.

It is often useful to leave a lance unpromoted (see below) at the far side of the board. However, since a lance cannot move backward or to the sides, it must promote if it arrives at the farthest rank.

A bishop can move any number of free squares along any one of the four diagonal directions.

Because it cannot move orthogonally, an unpromoted bishop can only reach half the squares on the board.

A rook can move any number of free squares along any one of the four orthogonal directions.

A pawn can move one square directly forward. It cannot retreat.

Since a pawn cannot move backward or to the sides, it must promote (see below) if it arrives at the farthest rank. However, in practice, a pawn is promoted whenever possible.

There are two restrictive rules for where a pawn may be dropped (see below).

Shogi - Promotion

A player's promotion zone is the three farthest ranks, at the original line of the opponent's pawns and beyond — that is, the opponent's territory at setup. If a piece moves across the board at all within the promotion zone, including moves into, out of, or wholly within the zone, but not including drops (see below), then that player may choose to promote the piece at the end of the turn. Promotion is indicated by turning the piece over after it moves, revealing the character for the promoted piece.

Promoting a piece has the effect of changing how that piece moves. Each piece promotes as follows:

• A king or a gold general cannot promote, nor can pieces which are already promoted.
• A silver general, knight, lance, or pawn, when promoted, loses its normal movement and gains the movement of a gold general.
• A bishop or rook, when promoted, keeps its normal movement and gains the ability to move one square in any direction, like a king. This means a promoted bishop is able to reach any square on the board, given enough moves.

If a pawn, knight, or lance reaches the furthest rank, it must be promoted, since it would otherwise have no legal move on subsequent turns. For the same reason, a knight reaching the penultimate rank must be promoted.

When captured, pieces lose their promoted status. Otherwise, promotion becomes permanent.

Shogi - Drops

Captured pieces are truly captured in shogi. They are retained "in hand", and can be brought back into play under the capturing player's control. On any turn, instead of moving a piece, a player can take a piece that was previously captured and place it, unpromoted side up, on any empty square, facing the opponent. The piece is now part of the forces controlled by that player. This is termed dropping the piece, or just a drop.

A drop cannot capture a piece, nor does dropping within the promotion zone result in immediate promotion. However, either capture or promotion may occur normally on subsequent moves by the piece.

A pawn, knight, or lance may not be dropped on the furthest rank, since it would have no legal move on subsequent turns. Similarly, a knight may not be dropped on the penultimate rank.

There are two other restrictions when dropping pawns:

A pawn cannot be dropped onto the same file (column) as another unpromoted pawn controlled by the same player. (A tokin does not count as a pawn here.) A player who has an unpromoted pawn on every file is therefore unable to drop a pawn anywhere. For this reason, it is common to sacrifice a pawn in order to gain flexibility for drops.

A pawn cannot be dropped to give an immediate checkmate. Other pieces may be dropped to give immediate checkmate, however. A pawn that is already on the board may be advanced to give checkmate as well, and a pawn may be dropped where either it or another piece can mate on a subsequent turn.

It is very common for players to swap bishops, which face each other across the board. This leaves each player with a bishop "in hand" to be dropped later, and gives an advantage to the player with the stronger defensive position.

Shogi - Check and mate

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

To say "check!" in Japanese, one says "ōte!" (王手). This is perhaps an influence of Western chess, and is not required. Checkmate is called tsume (詰め) or ōtedzume (王手詰め).

Shogi - Game end

A player who captures the opponent's king wins the game. In practice this rarely happens, as a player will resign when loss is inevitable (as in International Chess).

If a player is not in check, but can make no legal move, then the game is a loss for that player. (It would be stalemate in International Chess).

In professional games, a player who makes an illegal move loses immediately. This includes violating the restrictions on pawn drops.

There are two other possible, if uncommon, ways for a game to end: repetition (千日手 sennichite) and impasse (持将棋 jishōgi).

If the same game position occurs four times with the same player to play, then the game is no contest. For two positions to be considered the same, the pieces in hand must be the same, as well as the position on the board. (However, if this occurs with one player giving perpetual check, then that player loses.)

The game reaches an impasse if both kings have advanced into their respective promotion zones and neither player can hope to mate the other or to gain any further material. If this happens then the winner is decided as follows: each rook or bishop scores 5 points for the owning player, and all other pieces except kings score 1 point each. (Promotions are ignored for the purposes of scoring.) A player scoring less than 24 points loses. If both players have at least 24 points, then the game is no contest.

Games which are no contest are usually counted as draws in amateur tournaments, but in professional tournaments the rules typically require the game to be replayed with colours reversed (possibly with reduced time limits).

Adapted from the Wikipedia article "Rules of the game", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki