Algebraic notation (chess)

When a piece makes a capture, an "x" is inserted immediately before the destination square. For example, Bxe5 (bishop captures the piece on e5). When a pawn makes a capture, the file from which the pawn departed is used to identify the pawn. For example, exd5 (pawn on the e-file captures the piece on d5). A colon (:) is sometimes used instead of "x", either in the same place the "x" would go (B:e5) or at the end (Be5:), but this is not the FIDE standard.

En passant captures are indicated by specifying the capturing pawn's file of departure, the "x", the destination square (not the square of the captured pawn), and (optionally) the suffix "e.p." indicating the capture was en passant.[4] For example, exd6 e.p.

Some texts, such as the Encyclopaedia of Chess Openings, omit any indication that a capture has been made. (For example, Be5 instead of Bxe5; ed6 instead of exd6 or exd6e.p.) When it is unambiguous to do so, a pawn capture is sometimes described by specifying only the files involved (exd or even ed). These shortened forms are sometimes called minimal or abbreviated algebraic notation.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

1) ...Rdf8, 2) R1a3, 3) Qh4e1

When two (or more) identical pieces can move to the same square, the moving piece is uniquely identified by specifying the piece's letter, followed by (in descending order of preference):

1. the file of departure (if they differ); or
2. the rank of departure (if the files are the same but the ranks differ); or
3. both the file and rank of departure (if neither alone is sufficient to identify the piece—which occurs only in rare cases where a player has three or more identical pieces able to reach the same square, as a result of one or more pawns having promoted).

In the diagram, both black rooks could legally move to f8, so the move of the d8-rook to f8 is disambiguated as Rdf8. For the white rooks on the a-file which could both move to a3, it is necessary to provide the rank of the moving piece, i.e., R1a3.

In the case of the white queen on h4 moving to e1, neither the rank nor file alone are sufficient to disambiguate from the other white queens. As such, this move is written Qh4e1.

As above, an "x" can be inserted to indicate a capture; for example, if the final case were a capture, it would be written as Qh4xe1.

When a pawn promotes, the piece promoted to is indicated at the end of the move notation, for example: e8Q (promoting to queen). In standard FIDE notation, no punctuation is used; in Portable Game Notation (PGN), as well as in Chess Life and English Wikipedia, pawn promotion is indicated by the equals sign (e8=Q). Other formulations used in chess literature include parentheses (e.g. e8(Q)) and a forward slash (e.g. e8/Q).

FIDE specifies draw offers to be recorded by an equals sign with parentheses "(=)" after the move on the score sheet.[5] This is not usually included in published game scores.

Castling is indicated by the special notations 0-0 (for kingside castling) and 0-0-0 (queenside castling). While the FIDE standard [6] is to use the digit zero (0-0 and 0-0-0), PGN uses the uppercase letter O (O-O and O-O-O).[7]

A move that places the opponent's king in check usually has the symbol "+" appended. Alternatively, sometimes a dagger (†) or the abbreviation "ch" is used. Some publications indicate a discovered check with an abbreviation such as "dis ch", or with a specific symbol. Double check is usually indicated the same as check, but is sometimes represented specifically as "dbl ch" or "++", particularly in older chess literature. The Encyclopaedia of Chess Openings omits any indication of check.

Checkmate at the completion of moves is represented by the symbol "#" in standard FIDE notation and PGN. The word mate is commonly used instead; occasionally a double dagger (‡) or a double plus sign (++) is used, although the double plus sign is also used to represent "double check" when a king is under attack by 2 enemy pieces simultaneously. A checkmate is represented by "≠" (the not equal sign) in the macOS chess application. In Russian and ex-USSR publications, where captures are indicated by ":", checkmate can also be represented by "X", "x", or "×".

The notation 1–0 at the completion of moves indicates that White won, 0–1 indicates that Black won, and ½–½ indicates a draw. In case of forfeit, scores 0–0, ½–0, and 0–½ are also possible. If player(s) lost by default, results are +/−, −/+, or −/−.

Often there is no indication regarding how a player won or lost (other than checkmate, see above), so simply 1–0 or 0–1 may be written to show that one player resigned or lost due to time control or forfeit. (Similarly, there is more than one way for a game to end in a draw.) Sometimes direct information is given by the words "White resigns" or "Black resigns", though this is not considered part of the notation but rather a return to the surrounding narrative text.

Some computer programs (and people) use a variant of algebraic chess notation termed long algebraic notation or fully expanded algebraic notation. In long algebraic notation, moves specify both the starting and ending squares, for example: e2e4. Sometimes these are separated by a hyphen, for example: Nb1-c3. Captures are still indicated using "x": Rd3xd7.

The long notation takes more space and thus is not as commonly used; however, it has the advantage of clarity, particularly for less-skilled players or players learning the game. Some books using primarily short algebraic notation use the long notation instead of the disambiguation forms described earlier.

A form of long algebraic notation (without piece names) is also notably used by the Universal Chess Interface (UCI) standard, which is a common way for graphical chess programs to communicate with chess engines (e.g., for AI).

In international correspondence chess the use of algebraic notation may cause confusion, since different languages employ different names (and therefore different letters) for the pieces; hence the standard for transmitting moves in this form of chess is ICCF numeric notation. In recent years, the majority of correspondence games have been played on on-line servers rather than by email or post, leading to a decline in the use of ICCF numeric notation.