FIDE recognizes for its own tournaments and matches only one system of notation, the Algebraic System, and recommends the use of this uniform chess notation also for chess literature and periodicals. Scoresheets using a notation system other than algebraic may not be used as evidence in cases where normally the scoresheet of a player is used for that purpose. An arbiter who observes that a player is using a notation system other than the algebraic should warn the player about of this requirement.

Description of the Algebraic System

  1. In this description, ‘piece’ means a piece other than a pawn.
  2. Each piece is indicated by the first letter, a capital letter, of its name. Example: K=king, Q=queen, R=rook, B=bishop, N=knight. (In the case of the knight, for the sake of convenience, N is used.)
  3. For the first letter of the name of the pieces, each player is free to use the first letter of the name which is commonly used in his country. Examples: F=fou (French for bishop), L=loper (Dutch for bishop). In printed periodicals, the use of figurines for the pieces is recommended.
  4. Pawns are not indicated by their first letter, but are recognized by the absence of such a letter. Examples: e5, d4, a5.
  5. The eight files (from the left to right for White and from right to left for Black) are indicated by the small letters, a, b, c, d, e, f, g, and h, respectively.
  6. The eight ranks (from bottom to top for White and from top to bottom for Black) are numbered 1, 2, 3, 4, 5, 6, 7, 8, respectively. Consequently, in the initial position the white pieces and pawns are placed on the first and second ranks; the black pieces and pawns on the eighth and seventh ranks.
  7. As a consequence of the previous rules, each of the sixty-four squares is invariably indicated by a unique combination of a letter and a number.

    Image description

  8. Each move of a piece is indicated by a) the first letter of the name of the piece in question and b) the square of arrival. There is no hyphen between a) and b). Examples: Be5, Nf3, Rd1. In the case of pawns, only the square of arrival is indicated. Examples: e5, d4, a5.
  9. When a piece makes a capture, an x is inserted between a) the first letter of the name of the piece in question and b) the square of arrival. Examples: Bxe5, Nxf3, Rxd1. When a pawn makes a capture, the file of departure must be indicated, then an x, then the square of arrival. Examples: dxe5, gxf3, axb5. In the case of an ‘en passant’ capture, the square of arrival is given as the square on which the capturing pawn finally rests and ‘e.p.’ is appended to the notation. Example: exd6 e.p.
  10. If two identical pieces can move to the same square, the piece that is moved is indicated as follows:
    1. If both pieces are on the same rank: by a) the first letter of the name of the piece, b) the file of departure, and c) the square of arrival.
    2. If both pieces are on the same file: by a) the first letter of the name of the piece, b) the rank of the square of departure, and c) the square of arrival.
    If the pieces are on different ranks and files methof 1) is preferred. In the case of capture, an x may be inserted between b) and c). Examples:
    1. There are two knights, on the squares g1 and e1, and one of them moves to the square f3: either Ngf3 or Nef3, as the case may be.
    2. There are two knights, on the squares g5 and g1, and one of them moves to the square f3: either N5f3 or N1f3, as the case may be.
    3. There are two knights, on the squares h2 and d4, and one of them moves to the square f3: either Nhf3 or Ndf3, as the case may be.
    If a capture takes place on the square f3, the previous examples are changed by the insertion of an x: 1) either Ngxf3 or Nexf3, 2) either N5xf3 or N1xf3, 3) either Nhxf3 or Ndxf3, as the case may be.
  11. If two pawns can capture the same piece or pawn of the opponent, the pawn that is moved is indicated by a) the letter of the file of departure, b) an x, c) the square of arrival. Example: If there are white pawns on squares c4 and e4 and a black pawn or piece on the square d5, the notation for White’s move is either cxd5 or exd5, as the case may be.
  12. In the case of the promotion of a pawn, the actual pawn move is indicated, followed immediately by the first letter of the new piece. Examples: d8Q, f8N, b1B, g1R.
  13. The offer of a draw shall be marked as (=).

PGN was devised around 1993, by Steven J. Edwards, and was first popularized via the Usenet newsgroup rec.games.chess.

Usage

PGN is structured "for easy reading and writing by human users and for easy parsing and generation by computer programs." The chess moves themselves are given in algebraic chess notation. The usual filename extension is ".pgn". There are two formats in the PGN specification, the "import" format and the "export" format. The import format describes data that may have been prepared by hand, and is intentionally lax; a program that can read PGN data should be able to handle the somewhat lax import format. The export format is rather strict and describes data prepared under program control, similar to a pretty printed source program reformatted by a compiler. The export format representations generated by different programs on the same computer should be exactly equivalent, byte for byte. PGN code begins with a set of "tag pairs" (a tag name and its value), followed by the "movetext" (chess moves with optional commentary).

Tag pairs

Tag pairs begin with an initial left bracket "[", followed by the name of the tag in plain text (ASCII). The tag value is enclosed in double-quotes, and the tag is then terminated with a closing right bracket "]". There are no special control codes involving escape characters, or carriage returns and linefeeds to separate the fields, and superfluous embedded spaces (or SPC characters) are usually skipped when parsing. PGN data for archival storage is required to provide seven bracketed fields, referred to as "tags" and together known as the STR (Seven Tag Roster). In export format, the STR tag pairs must appear before any other tag pairs that may appear, and in this order:

  1. Event: the name of the tournament or match event.
  2. Site: the location of the event. This is in "City, Region COUNTRY" format, where COUNTRY is the three-letter International Olympic Committee code for the country. An example is "New York City, NY USA".
  3. Date: the starting date of the game, in YYYY.MM.DD form. "??" are used for unknown values.
  4. Round: the playing round ordinal of the game within the event.
  5. White: the player of the white pieces, in "last name, first name" format.
  6. Black: the player of the black pieces, same format as White.
  7. EResult: the result of the game. This can only have four possible values: "1-0" (White won), "0-1" (Black won), "1/2-1/2" (Draw), or "*" (other, e.g., the game is ongoing).

The standard allows for supplementation in the form of other, optional, tag pairs. The more common tag pairs include:

  • Annotator: The person providing notes to the game.
  • PlyCount: String value denoting total number of half-moves played.
  • TimeControl: "40/7200:3600" (moves per seconds: sudden death seconds)
  • Time: Time the game started, in "HH:MM:SS" format, in local clock time.
  • Termination: Gives more details about the termination of the game. It may be "abandoned", "adjudication" (result determined by third-party adjudication), "death", "emergency", "normal", "rules infraction", "time forfeit", or "unterminated".
  • Mode: "OTB" (over-the-board) "ICS" (Internet Chess Server)
  • FEN: The initial position of the chess board, in Forsyth-Edwards Notation. This is used to record partial games (starting at some initial position). It is also necessary for chess variants such as Fischer random chess, where the initial position is not always the same as traditional chess. If a FEN tag is used, a separate tag pair "SetUp" must also appear and have its value set to "1".

Movetext

Image descriptionThe movetext describes the actual moves of the game. This includes move number indicators (numbers followed by either one or three periods; one if the next move is White's move, three if the next move is Black's move) and movetext Standard Algebraic Notation (SAN). For most moves the SAN consists of the letter abbreviation for the piece, an "x" if there is a capture, and the two-character algebraic name of the final square the piece moved to. The letter abbreviations are "K" (king), "Q" (queen), "R" (rook), "B" (bishop), and "N" (knight). The pawn is given an empty abbreviation in SAN movetext, but in other contexts the abbreviation "P" is used. The algebraic name of any square is as per usual Algebraic chess notation; from white's perspective, the leftmost square closest to white is a1, the rightmost square closest to the white is h1, and the rightmost (from white's perspective) square closest to black side is h8. In a few cases a more detailed representation is needed to resolve ambiguity; if so, the piece's file letter, numerical rank, or the exact square is inserted after the moving piece's name (in that order of preference). Thus, "Nge2" specifies that the knight originally on the g-file moves to e2. SAN kingside castling is indicated by the sequence "O-O"; queenside castling is indicated by the sequence "O-O-O" (note that these are capital letter "O"s, not numeral "0"s). Pawn promotions are notated by appending an "=" to the destination square, followed by the piece the pawn is promoted to. For example: "e8=Q". If the move is a checking move, the plus sign "+" is also appended; if the move is a checkmating move, the number sign "#" is appended instead. For example: "e8=Q#". An annotator who wishes to suggest alternative moves to those actually played in the game may insert variations enclosed in parentheses. He may also comment on the game by inserting Numeric Annotation Glyphs (NAGs) into the movetext. Each NAG reflects a subjective impression of the move preceding the NAG or of the resultant position. If the game result is anything other than "*", the result is repeated at the end of the movetext.

Comments

Comments are inserted by either a ";" (a comment that continues to the end of the line) or a "{" (which continues until a matching "}"). Comments do not nest.

Example

Here is a sample game in PGN format:

[Event "F/S Return Match"]
[Site "Belgrade, Serbia Yugoslavia|JUG"]
[Date "1992.11.04"]
[Round "29"]
[White "Fischer, Robert J."]
[Black "Spassky, Boris V."]
[Result "1/2-1/2"]
1. e4 e5 2. Nf3 Nc6 3. Bb5 {This opening is called the Ruy Lopez.} 3... a6
4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nb8 10. d4 Nbd7
11. c4 c6 12. cxb5 axb5 13. Nc3 Bb7 14. Bg5 b4 15. Nb1 h6 16. Bh4 c5 17. dxe5
Nxe4 18. Bxe7 Qxe7 19. exd6 Qf6 20. Nbd2 Nxd6 21. Nc4 Nxc4 22. Bxc4 Nb6
23. Ne5 Rae8 24. Bxf7+ Rxf7 25. Nxf7 Rxe1+ 26. Qxe1 Kxf7 27. Qe3 Qg5 28. Qxg5
hxg5 29. b3 Ke6 30. a3 Kd6 31. axb4 cxb4 32. Ra5 Nd5 33. f3 Bc8 34. Kf2 Bf5
35. Ra7 g6 36. Ra6+ Kc5 37. Ke1 Nf4 38. g3 Nxh3 39. Kd2 Kb5 40. Rd6 Kc5 41. Ra6
Nf2 42. g4 Bd3 43. Re6 1/2-1/2

Handling chess variants

Many chess variants can be recorded using PGN, provided the names of the pieces can be limited to one character, usually a letter and not a number. They are typically noted with a tag named "Variant" giving the name of the rules. The term "Variation" must be avoided, as that refers to the name of an opening variation. Note that traditional chess programs can only handle, at most, a few variants. Forsyth-Edwards Notation (FEN) is used to record the starting position for variants (such as Chess960) which have initial positions other than the orthodox chess initial position. Plycount is a chess term for the total number of moves in a game, counting each player's move as one. It is an optional part of the standard PGN description of a chess game.