Chess Notation Glossary
Plain-English definitions for every term you'll meet when reading chess notation — algebraic notation, SAN, PGN, FEN, captures, check, castling, promotion, and the rest. For a guided walkthrough, start with How to Read Chess Notation.
- Algebraic notation(SAN, Standard Algebraic Notation)
The modern, universal system for recording chess moves. Each square has an absolute name (file letter a–h, rank number 1–8) and each piece a letter (K, Q, R, B, N — pawns omit the letter). All chess books, databases, and engines use algebraic notation today.
Example:
Nf3 = knight to f3- Annotation marks(!! ! ? ?? !? ?!)
Symbols added by commentators to evaluate a move. !! = brilliant, ! = good, !? = interesting, ?! = dubious, ? = mistake, ?? = blunder. They do not affect the move itself — they are commentary.
- Capture(x)
A move that takes an opponent's piece. Written with a lowercase x between the moving piece and the destination square. For pawn captures the file the pawn came from is written first (no piece letter).
Example:
Nxf3 = knight captures on f3 · exd5 = e-file pawn captures on d5- Castling(O-O, O-O-O)
The only move where two pieces move at once: the king moves two squares toward a rook, and the rook jumps to the king's other side. O-O is kingside (short) castling; O-O-O is queenside (long) castling. Always written with capital O's, not zeroes.
- Check(+)
A move that attacks the opponent's king, forcing them to escape on their next move. Marked with a plus sign after the move.
Example:
Qh5+ = queen to h5, with check- Checkmate(# or ++)
A check the opponent cannot escape. The game ends. Marked with # (most common) or ++ (older books) after the move.
Example:
Qh7# = queen to h7, checkmate- Descriptive notation(P-K4, N-KB3)
An older system that named squares relative to each player's perspective, using piece names rather than coordinates. Standard in English-language chess books before about 1990. Modern books no longer use it.
Example:
P-K4 (descriptive) = e4 (algebraic)- Disambiguation
Extra information added to a move when two pieces of the same type could move to the same square. The file or rank of the moving piece is added between the piece letter and the destination.
Example:
Nge2 = the knight on the g-file moves to e2 (the other knight could also move there)- Double check(++)
A check delivered by two pieces simultaneously — usually a discovered check where the moving piece also gives check. The king must move; blocking or capturing won't stop both attackers.
- En passant(e.p.)
A special pawn capture: if a pawn advances two squares from its starting position and lands beside an opponent's pawn, that opponent may capture it as if it had only moved one square. The capture must be made immediately on the next move.
Example:
exd6 e.p. = the e-pawn captures the d-pawn en passant- FEN(Forsyth–Edwards Notation)
A compact text format that describes a single chess position — piece placement, side to move, castling rights, en passant target, halfmove clock, and full move number. Used to share or store positions outside a full game.
Example:
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 (the start position)- File
A column on the chess board. Files are labelled a–h from left to right from White's perspective. Always lowercase in algebraic notation.
- Half-move(ply)
A single move by one side. A full move number contains two half-moves: White's move and Black's reply. Engines and databases often count in half-moves (ply).
- Long algebraic notation
A variant of algebraic notation that includes the starting square as well as the destination. Less common in books, but used by some engines and PGN exports.
Example:
Ng1-f3 (long algebraic) vs Nf3 (standard algebraic)- Move number
A number followed by a dot, marking each pair of moves in a game. White's move comes first, then Black's. Three dots after the number (e.g. 3...) indicate Black's move is being shown without White's.
Example:
1. e4 e5 2. Nf3 Nc6- PGN(Portable Game Notation)
The standard plain-text file format for storing chess games. A PGN file contains tag pairs (metadata like player names and result) followed by the movetext. Every chess website, database, and engine reads PGN.
- Piece letters(K Q R B N)
The single capital letters used to abbreviate each piece. K = King, Q = Queen, R = Rook, B = Bishop, N = Knight (because K is taken). Pawns have no letter — a move like e4 is automatically a pawn move.
- Promotion(=)
When a pawn reaches the opposite end of the board (rank 8 for White, rank 1 for Black), it must be promoted to a queen, rook, bishop, or knight. Written with an equals sign followed by the new piece's letter.
Example:
e8=Q = pawn promotes to a queen on e8- Rank
A row on the chess board. Ranks are numbered 1–8 from White's side (bottom) to Black's side (top). White's pieces start on ranks 1–2; Black's on ranks 7–8.
- Square name
The unique two-character label for any of the 64 squares: a file letter followed by a rank number. The bottom-left square (from White's view) is a1; the top-right is h8.
- Stalemate
A position where the player to move has no legal moves but is not in check. The game is a draw. Stalemate is not noted with a special symbol in moves — it appears in the result (1/2-1/2).
- Tag pair(PGN tag)
A piece of metadata in a PGN file, written in square brackets at the top of the game. Standard tags include Event, Site, Date, Round, White, Black, and Result.
Example:
[White "Morphy, Paul"]