Wa shogi

Wa shogi (和将棋, wa shōgi, harmony chess) is a large board variant of shogi (Japanese chess) in which all of the pieces are named for animals. It is played either with or without drops. Because of the terse and often incomplete wording of the historical sources for the large shogi variants, except for chu shogi and to a lesser extent dai shogi (which were at some points of time the most prestigious forms of shogi being played), the historical rules of wa shogi are not clear. Different sources differ significantly in the moves attributed to the pieces. Presented here are the piece movements that are somewhat standard among modern players of wa shogi, among which the game is played with drops.

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

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 no longer literally descriptive.) A move consists of moving a single piece on the board and potentially promoting that piece or displacing (capturing) an opposing piece. 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, ×). If an oxcart or sparrow pawn, which cannot retreat or move aside, advances across the board until it can no longer move, 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:

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 crane king, violent wolf, violent stag, blind dog, climbing monkey, flying goose, flying cock, strutting crow, swooping owl and the 9 sparrow pawns on each side.

The liberated horse and cloud eagle can move along a limited number (2 or 3) of free (empty) squares along a straight line in a certain directions. Other than the limited distance, they move like ranging pieces (see below).

The treacherous fox can jump, that is, it can pass over any intervening piece, whether friend or foe, with no effect on either.

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 cloud eagle, flying falcon, running rabbit, swallow's wings, liberated horse and oxcart.

A player's promotion zone consists of the three farthest ranks, at the original line of the opponent's treacherous fox, running rabbit and beyond. If a piece crosses the board within the promotion zone, including moves into, out of, or wholly within the zone 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.

Descriptions of wa shogi from historical texts make no mention that drops were ever used; however, many people in modern times enjoy playing this game with drops. Promoted pieces with the same move (VW/GB and BE/PO) have different names, which suggests the game used drops after demotion on capture, as otherwise these pieces would be fully equivalent, and there would be no need to distinguish them. The rules pertaining to drops are usually based on modern shogi.

When a player makes a move such that the opponent's crane king could be captured on the following move, the move is said to give check to the crane king; the crane king is said to be in check. If a player's crane king is in check and no legal move by that player will get the crane king out of check, the checking move is also mate, and effectively wins the game. A player is not allowed to give perpetual check, and loses if he does so.

A player who captures the opponent's crane king 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 four 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 crane kings stand well fortified in their respective promotion zones (when played with drops) or when players run out of material (without drops), so that neither player can hope to mate the other or to gain any further material.

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 differs in several respects. Modifications have been made for wa shogi. A typical example is SP 8f. The first letter represents the piece moved: SP = sparrow pawn, OC = oxcart, LH = liberated horse, CM = climbing monkey, BD = blind dog, SO = swooping owl, SC = strutting crow, FC = flying cock, FG = flying goose, VS = violent stag, VW = violent wolf, RR = running rabbit, TF = treacherous fox, SW = swallow's wings, FF = flying falcon, CE = cloud eagle and, CK = crane king. Promoted pieces have a + added in front of the letter e. g., +SP for a golden bird (promoted sparrow 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 11k 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, FFx7c= indicates a flying falcon capturing on 7c 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. This can only apply to golden birds. Moves are commonly numbered as in chess.