It is thought that the original Japanese chess dates from about the 8th or 9th century, and was introduced either from China or from Burma and Thailand.
While there are references to the game dating from the 10th century, the earliest account of the rules are given in a history text entitled NICHUREKI dated between 1126 and 1130. The description gives the moves of the pieces, says that all pieces promote to Gold General on reaching the 3rd rank, and that baring the opponents King wins the game. There is, however, no mention of the number of pieces, size of the board, or the initial set-up.
Versions of the game have been reconstructed using either an 8x9 or 8x8 board (and it is believed possible that both versions may have existed). The 8x8 reconstruction has only one Gold General in the array, with the 8x9 having an extra Gold on the back rank as in Modern Shogi. The 8x9 square version is the one that is described here.
There are no drops in Heian Shogi, and the game does not have Rooks or Bishops. The pieces in Heian Shogi therefore have very limited powers of movement and the game is much slower and less interesting than later variants. Heian Shogi is therefore primarily of historical interest only.
The reconstruction of Heian Shogi included in this program is played on a board of 8 x 9 squares and each player has 18 pieces (including 9 pawns).
The pieces are flat and wedge-shaped and are not distinguished by colour. Although the pieces are of uniform colour the first player is still conventionally referred to as 'Black' and the second player as 'White'. Ownership of the pieces is indicated by the direction in which they face, with a player's pieces always pointing towards the opponent.
The players make alternate moves, with the object being to capture the opposing 'King'.
As in orthodox chess, when a 'King' is about to be captured next move and no legal move can be made to prevent the capture, the piece is said to be 'Checkmated'.
In common with other ancient chess games, the game can also be won by capturing all pieces except the 'King' (the 'bare king' rule). A bare King may secure a draw if it can also bare the opposing 'King' on the following move.
On each turn a player can move one piece according to its power of movement to a vacant square on the board, or to a square occupied by an enemy piece (in which case the enemy piece is captured and removed from the game).
The opening setup is shown below.
board has nine columns and eight rows. Each player has, on the bottom row
at his side of the board, from left to right: Lance, Knight, Silver General,
Gold General, King, Gold General, Silver General, Knight, Lance. On the
third rows, each player has nine pawns.
Below, you see the different types of the moves of the pieces explained in a diagram, and repeated in text. All pieces take in the same way as they move.
The king moves as a king in orthodox chess, and does not promote.
The gold general can move one square orthogonally, or diagonally forward, so the only direction the gold general cannot go is diagonally backwards. The gold general does not promote.
The silver general can move one square diagonally, or straight forward, (so: not straight to the left or right or back). The silver general promotes to a gold general.
The knight is explained below (forward orthodox chess Knight move). It promotes to gold general.
The lance moves as a rook, but only straight forward, not backwards and not to the left or right. It promotes to gold general.
The pawn moves one square forward. It promotes to tokin - the tokin is a piece that moves as gold general (and, in this variant, is further not distinguishable from a gold general.)
The 'Knight' is the only piece in Heian Shogi that has the power to jump over occupied squares. The Heian 'Knight' has the same move as the equivalent piece in the Western game (ie: it may move one square orthogonally then one square diagonally), except that its move is limited to the forward direction only.
Each player has a Promotion Zone consisting of the three ranks (rows of squares) furthest away from him. All pieces except the 'King' can promote to 'Gold General' on entering, moving within, or leaving the Promotion Zone.
Promotion is not compulsory unless the piece would be unable to make a further legal move in its unpromoted state. The 'Pawn' and 'Lance' must therefore promote on reaching the last rank (that furthest from the player) and the 'Knight' must promote if it reaches the 2nd last rank. There can be advantages with some pieces of not promoting immediately on entering the Promotion Zone.
As in all the games in the Shogi family, the promoted rank is shown on the reverse side of the piece, and the piece is turned over on promotion to reveal the new rank.
Unlike in the modern game of Shogi, captured pieces in Heian Shogi can not be 'dropped' back into play. A captured piece is removed from play and takes no further part in the game.
Handicaps are often given when players of unequal strength play Shogi in Japan. The reason that handicap play is common is that the handicap system in Shogi works far better than that used in orthodox chess.
In a handicap game a player offers a handicap of one or more pieces to an opponent of less strength. While Heian Shogi does not lend itself to handicaps as well as Shogi, provision for handicap play has nevertheless been included in this program.
The same rules for handicaps as in Shogi have been adopted. Under these rules, the player offering the handicap plays 'White'and his opponent (as 'Black') removes the handicap pieces as the first move of the game. In handicap play 'White' therefore makes the first move on the board.
The following notation system is used for recording Heian Shogi games in this program.
The files are designated by numbers (1 to 9), and the ranks by letters (a to h). The files are numbered from right to left (in the Japanese fashion), and the ranks from top to bottom (from Black's point of view). The top right square is therefore 1a.
A move is described by giving:
A 'Lance' moving from 5d to 5c (which was occupied by an enemy piece) and promoting is therefore recorded as L5dx5c+.
NOTE: This system is based on the official notation system of 'The Shogi Association'; the difference being that in the official system the starting square is only included if more than one piece of the same type can reach the destination square.
The information on this game was based on an article by John Fairbairn, titled Shogi History & the Variants in the September 1980 issue of Shogi magazine.
Small changes and additions to the texts of Steve Evans were made by Hans Bodlaender.