The King's Game

Game Components

Ōgi pits two players against each other, seated face to face around an 8×8 board — 64 squares. In the tradition of Japanese board games, the players are called 先手(Sente), the player who moves first, and 後手(Gote), the player who moves second.

In the West, Sente and Gote are often referred to as Black and White, with Black making the first move.

Each player starts the game with 16 pieces. These pieces are flat, shaped like an irregular pentagon, and resemble an arrowhead. They come in several slightly different sizes. The pieces of both players are identical in appearance: only the pointed tip, oriented toward the opponent's camp, indicates ownership. The pieces range from the most important (the largest) to the least important (the smallest) as follows:

• 1 King
• 1 Princess
• 2 Rooks
• 2 Bishops
• 2 Knights
• 8 Fu

Each piece bears its name in kanji, drawn in black ink. Only one piece has a promoted form: the Fu (歩), whose reverse side bears the character of the Tokin (と). When a Fu is flipped to this side during the game, it means it has been promoted and now has different movement abilities. No other piece has a promoted state.

Example with the Fu:

Unpromoted side (front)

Promoted side (back)

The King can be represented by two characters, 王 and 玉: they are nevertheless the same piece (same rules and same movements); only the representation differs. This Jeweled King (玉), noted K^' (k^' for Gote), is a purely cosmetic variant of the King (K^), used only in Ōgi versus Ōgi games. By convention, both historical and honorific, it is assigned to the player with the lower rating (measured, for example, in Elo), or to Sente if ratings are equal; the other player then receives the ordinary King (王). The lower-ranked player thus expresses their respect toward the higher-ranked player.

Below is the list of pieces and, for each one, its name, the Japanese character used on the piece, as well as its notation abbreviation. These abbreviations follow the EPIN convention: uppercase letters denote Sente's pieces, lowercase letters Gote's (for example K^ for Sente's King, k^ for Gote's). Only the Fu has a promoted form, the Tokin, noted T. The images show the two available representation styles.

Pieces

Name	Unpromoted				Promoted
	Abbr.	Kanji	Image (Eastern)	Image (Western)	Abbr.	Kanji	Image (Eastern)	Image (Western)
King	K^	王			—	—	—	—
Jeweled King	K^'	玉			—	—	—	—
Princess	I	姫			—	—	—	—
Rook	R	飛			—	—	—	—
Bishop	B	角			—	—	—	—
Knight	N	騎			—	—	—	—
Fu	F	歩			T	と

Rules of the Game

Objective

The goal of the game is to checkmate the opposing King: to place it under an attack from which it can no longer escape. As in shōgi and Western chess, putting or leaving one's own King in check is illegal; the King is therefore never actually captured — checkmate decides the game. A game can also end in other ways (resignation, draw): see End of the game.

Setup

At the start of the game, the two players place their pieces on the board, each oriented toward the opponent's camp. The arrangement mirrors that of chess:

Initial position of an Ōgi game.

Unless otherwise indicated, diagrams are shown from Sente's point of view, with Sente at the bottom. Files are labelled a to h from left to right, and ranks 1 to 8 from bottom to top (from Sente's point of view). In movement diagrams, highlighted squares indicate the possible destinations of the pictured piece (a move, or a capture if an opposing piece stands there).

First player's camp (Sente)

Rank 1: Rook, Knight, Bishop, Princess, Jeweled King, Bishop, Knight, Rook. Rank 2: one Fu on each square. These Fu, on their starting rank, are eligible for the double step.

Second player's camp (Gote)

Rank 8: Rook, Knight, Bishop, Princess, King, Bishop, Knight, Rook. Rank 7: one Fu on each square, also eligible for the double step. Ranks 3 to 6 are empty. As in chess, the two camps face each other: the King and the Princess occupy adjacent files (the arrangement is therefore not symmetric under a 180° rotation).

Piece Movements

On each turn, a player performs exactly one of the following two actions: either move a piece already on the board (which may result in a capture and/or a promotion), or drop a previously captured piece. Players alternate turns; Sente moves first.

King

Movements: King

The King (玉 / 王) moves a single square per turn, in any direction (forward, backward, left, right or diagonally), and captures the same way. It cannot be promoted.

Princess

Movements: Princess

The Princess (姫) combines the powers of the Bishop and the Knight: it can either slide diagonally over any distance (without jumping over pieces), or leap in an “L” shape (two squares then one perpendicular) in all eight directions, passing over any intervening pieces. It has no straight orthogonal move (that is the Rook's domain) and captures the same way it moves. It cannot be promoted.

Rook

Movements: Rook

The Rook (飛) moves any number of squares in a straight line, along a rank or a file, never jumping over pieces. It captures by ending its move on the opposing piece. It cannot be promoted.

Bishop

Movements: Bishop

The Bishop (角) moves diagonally over as many squares as desired, without jumping over pieces, and captures by stopping on the opposing piece. It cannot be promoted.

Knight

Movements: Knight

The Knight (騎) moves in an “L” shape: two squares in one direction then one square perpendicular, in all eight directions (forward, backward and sideways), for up to eight possible destinations. It jumps over any intervening pieces and captures by landing on an opposing piece. It therefore moves exactly like the Knight in Western chess — not like the shōgi knight. It cannot be promoted.

Fu

Movements: Fu

The Fu (歩) moves a single square straight ahead, on the same file, and can never move backward. It captures the same way: by advancing one square straight ahead onto an opposing piece (there is no diagonal capture as in Western chess).

Double step. A Fu that has not yet moved since the start of the game — it is then still on its starting rank — may advance two squares straight ahead in a single move, provided that both the intermediate square and the destination square are empty. The double step cannot capture.

The double step: a Fu on its starting rank

This eligibility disappears as soon as the Fu moves for the first time (one or two squares) and never returns: a Fu that is captured and later dropped does not regain the double-step privilege.

Tokin (promoted Fu)

Movements: Tokin

The Tokin (と) is the game's only promoted form. It moves one square to one of six destinations: one square orthogonally in the four directions, or one square diagonally forward (two diagonals). It cannot move diagonally backward. This is the movement of the shōgi “Gold General”. The Tokin cannot be promoted further.

Promotion

A player's promotion zone is their last rank: rank 8 for Sente, rank 1 for Gote. This is exactly the promotion zone of chess.

Promotion is mandatory and automatic when a Fu ends a move on the last rank: it is immediately replaced by a Tokin (there is therefore no choice). No other piece has a promoted form, and a Tokin cannot promote again. A drop never triggers promotion — and dropping a Fu on the last rank is forbidden anyway (see Restrictions).

Sente's promotion zone: the last rank (in yellow)

Captures and pieces in hand

When a piece is captured, it does not leave the game for good: it is removed from the board and placed in the reserve of the player who captured it. It is then said to be held in hand. In Japanese, these pieces are called 持ち駒(mochigoma) or 手駒(tegoma).

The transformation of the captured piece follows two rules, applied in order:

1. Demotion. The piece reverts to its unpromoted form: a captured Tokin becomes a Fu again. Pieces without a promoted form are unchanged by this step.
2. Change of camp. The piece joins its captor's camp (its case is flipped: uppercase ↔ lowercase).

Every captured piece thus changes camp: it ends up in its captor's camp and becomes, in principle, droppable again (subject to the restrictions below for the Fu). It is never possible to keep a Tokin in hand: it always becomes a Fu again.

Instead of moving a piece already on the board, a player may, on their turn, drop a piece they hold in hand: they place it on an empty square, and the piece then joins their active pieces. Each drop counts as a full move. A drop cannot capture (the destination square must be empty) nor promote the piece, even inside the promotion zone. A dropped Fu arrives without a prefix: it does not acquire the double-step privilege.

Restrictions on drops

Thanks to the systematic change of camp, every piece in hand belongs to its holder's camp and can, in principle, be dropped. Three restrictions, specific to the Fu, limit this. A Fu drop is illegal if it violates any of them:

• No Fu on the last rank. A Fu cannot be dropped on its own last rank (rank 8 for Sente, rank 1 for Gote), where it would have no legal move left.
• Nifu (二歩(nifu)). A Fu cannot be dropped on a file where the player already has an unpromoted Fu on the board. A Tokin on the file does not trigger nifu: only unpromoted Fu count.
• Uchifuzume (打ち歩詰め(uchifuzume)). A Fu cannot be dropped on a square if doing so would deliver checkmate. Simply giving check with a Fu drop is allowed; only mate is forbidden.

The other pieces (Rook, Bishop, Knight, Princess) always have at least one legal move from any square of an 8×8 board: no square restriction applies to them.

Check

A King is in check (王手(ōte)) when it is attacked by an opposing piece, meaning it could be captured on the next move. A player whose King is in check must play a move that ends the check: moving the King to a safe square, capturing the checking piece, or interposing a piece on the line of attack.

A move that leaves one's own King in check is illegal — whether it creates a new check or fails to parry an existing one. Check does not need to be announced. Since self-check is forbidden, the King is never actually captured: a player in check with no legal move to escape it is checkmated and loses the game.

End of the game

The game ends in one of the following cases:

• Checkmate: the player to move is in check and has no legal move to escape it. They lose.
• Stalemate: the player to move has no legal move (drops included) and is not in check. The game is a draw. (This is a deliberate departure from shōgi, where stalemate loses; Ōgi aligns here with chess.)
• Threefold repetition: if the same position occurs three times during the game (not necessarily in a row), the game is a draw, as in chess. A “draw by perpetual check” therefore remains available to the defender.
• Dead position: if a position arises in which neither player can checkmate by any series of legal moves, the game is immediately drawn. In Ōgi, however, this can never happen: a captured piece goes to the capturer's hand and remains droppable — nothing ever leaves the game, and the total material stays invariant from the first position to the last.
• Draw by agreement: the players may agree at any time that the game is a draw.
• Resignation: a player concedes the game; the opponent wins.
• 50-move rule: if 50 moves by each player (that is, 100 half-moves) are played without any capture and without any move of an unpromoted Fu, the game is automatically a draw. A drop — even a Fu drop — is neither a capture nor a move, so it does not reset the counter.

A game therefore has exactly one of three results: 1–0 (Sente wins), ½–½ (draw) or 0–1 (Gote wins). Checkmate and resignation are decisive; stalemate, threefold repetition, dead position, draw by agreement and the 50-move rule are draws.

Illegal moves

On Sashité, an illegal move does not end the game: it is simply refused. The player keeps the turn and must submit another move. The following constitute illegal moves:

• Playing anything other than a move or a drop.
• Moving a piece to a square not allowed by its movement rules.
• For sliding pieces (Rook, Bishop, and the Bishop component of the Princess), passing through an occupied square. (The Knight, and the Knight component of the Princess, jump: they are exempt.)
• Moving a piece onto a square occupied by a friendly piece.
• Leaving one's own King in check (any move that creates or fails to resolve a check on one's King).
• Performing a double step with a Fu that is not (or no longer) eligible for it.
• Dropping on a non-empty square.
• Dropping a piece whose camp does not match the player's.
• Dropping a Fu on the last rank.
• Dropping a Fu on a file where one already has an unpromoted Fu (nifu).
• Dropping a Fu that would deliver checkmate (uchifuzume).
• Promoting a piece with no promoted form (King, Princess, Rook, Bishop, Knight).
• Promoting during a drop.
• Promoting an already promoted piece (Tokin).
• Failing to promote when it is mandatory (a Fu reaching the last rank must become a Tokin).

Cultural narrative and urban legend

Ōgi preserves the fundamental principles of Shōgi, but distinguishes itself through a contemporary narrative rather than documented historical origins. The game was formalized and named by the French author Cyril Veltin, who recounts having discovered it while observing, one summer evening, a strange game being played in a park in Ōsaka.

At the heart of this cultural narrative lies an urban legend involving a yōkai named Komayō, who is said to sometimes invite players to a game, under the light of the full moon.

Some players claim to have seen her. Others do not believe.