shogi.rs | Rules

Basics

Shogi is played on a board with 9 ranks (rows) and 9 files (columns) labeled a-b and 1-9 respectively. Numbering starts in the top right. Promotion may happen at the end of turn whenever a piece has moved into or out of the final 3 ranks.

Instead of moving an existing piece, a player may choose to place (or "drop") a previously captured piece in an unoccupied square instead. Placed pieces are always unpromoted and may generally be placed anywhere with a few notable exceptions:

• A piece must have a valid move. This prevents pawns and lances from being placed in the final rank, and knights may not be placed in either of the final two ranks.
• A pawn cannot be put into a file where the player already has an existing unpromoted pawn.
• A pawn cannot be dropped to checkmate. However, it can be dropped to check -- and all other pieces may be dropped to checkmate.

Pieces

Name (Alternate Name) [Abbreviation]

King [K]

Rook [R]

Bishop [B]

Gold General (Gold) [G]

Silver General (Silver) [S]

Knight [N]

Lance [L]

Pawn [P]

(King does not promote)

Promoted Rook (Dragon/Dragon King) [+R]

Promoted Bishop (Horse/Dragon Horse) [+B]

(Gold does not promote)

Promoted Silver [+S]

Promoted Knight [+N]

Promoted Lance [+L]

Promoted Pawn (tokin) [+P]

The piece symbols are meant to graphically represent their movement, with the green square or letter being the square the piece starts on. Red squares are valid places to move. Arrows indicate being able to move any number of places in that direction, until hitting the edge of the board, being blocked by a friendly piece, or capturing an enemy piece.

Knights move forward two ranks and left or right one file, and do not consider any intervening space as blocking.

Notable differences from Chess

Pawns only ever move forward in the same file one square at a time. The first move cannot move two ranks. There is no en passant capture, and pawns do not capture diagonally. They may only capture the piece directly in front of them.

Shogi knights can only move in the two forward most places chess knights can. Shogi knights can still jump over pieces however.

Notes on optional promotion

In most cases accepting a promotion is strictly superior to not accepting one. There are a few exceptions where the original movement may be more useful:

• A knight in the 3rd to last rank (it must promote in the last two ranks).
• A lance in the 3rd to last or penultimate rank, though the movement of the promoted lance in the penultimate rank is strictly superior.
• A silver in any of the final three ranks. Backward diagonal movement may be desired. The promoted silver movement is a trade off with the standard silver movement.

Annan Shogi

Annan Shogi is a variant of shogi played in one of a few ways. This site only supports a single form. Denote the piece movement described above as the "normal movement". When a piece is directly in front of another friendly piece, it uses "annan movement" and must move using the "normal movement" of the piece behind it.

This means that a rook directly in front of a pawn may only move a single square forward.

When three friendly pieces are in a contiguous file, the lead piece moves as the normal movement of the middle piece. There is no recursive movement pattern copying.

To prevent the pawns directly in front of the rook and bishop from immediately moving as rooks and bishops, the starting positions of these two pawns are moved forward one rank.

Rules intended to ensure each piece has a valid move are adjusted. This means that all promotions are optional, and pieces like the pawn and lance can be placed in any rank. These may eventually have valid movement due to other friendly pieces.