Yari shogi

The objective of the game is to capture your opponent's general.

Setup

Two players, Black and White (or 先手 sente and 後手 gote), play on a board ruled into a grid of 9 ranks (rows) by 7 files (columns). The squares are undifferentiated by markings or color.

Each player has a set of 14 wedge-shaped pieces, of slightly different sizes. From largest to smallest (most to least powerful) they are:

• 1 general
• 2 yari rooks
• 2 yari bishops
• 2 yari knights
• 7 pawns

Most of the English names were chosen to correspond to rough equivalents in Western chess, rather than as translations of the Japanese names.

Each piece has its name in the form of two kanji written on its face. On the reverse side of some pieces are one or two other characters, often in a different color (commonly red instead of black); this reverse side is turned up to indicate that the piece has been promoted during play. The pieces of the two sides do not differ in color, but instead each piece is shaped like a wedge, and faces forward, toward the opposing side. This shows who controls the piece during play.

Listed here are the pieces of the game with their Japanese representation:

Each side places his pieces in the positions shown, pointing toward the opponent.[1]

• In the rank nearest the player:
  • The general is placed in the center file.
  • The two yari bishops are placed in the adjacent two files to left of the general.
  • The two yari knights are placed in the two adjacent files to the right of the general.
  • The two yari rooks are placed in the far corners.

That is, the first rank is:

• In the third rank, the seven pawns are placed one in each file.

The players alternate making a move, with Black moving first. (The traditional terms 'black' and 'white' are used to differentiate the sides during discussion of the game, but are not literally descriptive.) A move consists of moving a single piece on the board and potentially promoting that piece, displacing (capturing) an opposing piece or dropping a captured piece onto an empty square of the board. Each of these options is detailed below.

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 (meaning 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 knight is an exception, in that it is not required to move in a straight line.

If a piece that cannot retreat or move aside advances across the board until it can no longer move, it must promote.[1] This applies to the pawn, yari knight, yari bishop and yari rook upon reaching the farthest rank, and to the yari knight upon reaching either of the two farthest ranks.

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:

The king and pawn 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.)[1]

The yari knight can jump, that is, it can pass over any intervening piece, whether friend or foe, with no effect on either.[1]

Many pieces can move any number of empty squares along a straight 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 yari rook, yari bishop and yari knight.

A player's promotion zone consists of the three farthest ranks, at the original line of the opponent's pawns and beyond (that is, the opponent's territory at setup).[1] If a piece crosses the board 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 effected by turning the piece over after it moves, revealing the name of its promoted rank.

Promoting a piece has the effect of changing how that piece moves until it is removed from the board. Each piece promotes as follows:

• A general cannot promote, nor can pieces which are already promoted.[1]
• A yari bishop or yari knight loses its normal movement and gains the ability to move one square orthogonally forward or sideways, diagonally forward and any number of free squares orthogonally backward.[1]
• A pawn, when promoted, keeps its normal movement and gains the ability to move one square diagonally forward or any number of free squares backward.[1]
• A yari rook, when promoted, keeps its normal movement and gains the ability to move any number of free squares backward.[1]

If a yari bishop, yari knight or pawn reaches the farthest rank, it must be promoted, since it would otherwise have no legal move on subsequent turns. When captured, pieces lose their promoted status.

Below are diagrams indicating each piece's movement. Pieces are paired with their promotion. Pieces with a grey heading start out in the game; those with a blue heading only appear on the board after promotion. Betza's funny notation has been included in brackets for easier reference.

Captured pieces are truly captured in yari 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 across the board, a player can take a piece he has previously captured and place it 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; that requires an additional move.[1]

Pieces that are dropped in the promotion zone do not promote as a result: Promotion requires that piece make a normal movement on a subsequent turn, as detailed under "Promotion", above.[1] Pieces that are promoted when captured lose that promotion; they are unpromoted when dropped back on the board.

A pawn, yari knight, or yari bishop may not be dropped on the farthest rank, since it would have no legal move on subsequent turns.

A pawn cannot be dropped into the same file (vertical column) as another unpromoted pawn controlled by the same player. (A yari silver, or promoted pawn, does not count as a pawn when considering this drop restriction.) 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.

Unlike shogi, a pawn can be dropped when the opponent would have no way to prevent his general being captured on the next move. In other words, a pawn can be dropped to give immediate mate.[1]

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

A player is not allowed to give perpetual check.

A player who captures the opponent's general wins the game. In practice this rarely happens, as a player will resign when checkmated, as otherwise when loss is inevitable.

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 (千日手 sennichite) and impasse (持将棋 jishōgi).

If the same position occurs three times with the same player to play, then the game is no contest. (Recall, however, the prohibition against perpetual check.) For two positions to be considered the same, the pieces in hand must be the same, as well as the position on the board.

The game reaches an impasse if both generals 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 yari rook or yari bishop scores 5 points for the owning player, and all other pieces (except generals) score 1 point each. Promotions are ignored for the purposes of scoring. A player scoring less than 26 points loses. If both players have at least 26 points, then the game is no contest.

Games which are no contest are counted as draws in tournament style games.