PGN movetext

PGN means Portable Game Notation, a text format for recording games. A PGN game has two main sections. Descriptive tag information comes first. The movetext follows, recording how the game developed and ending with its result.

Moves are written in SAN, Standard Algebraic Notation. SAN uses forms such as e4 for a pawn advance, Nf3 for a knight moving to f3, and O-O for kingside castling, the special move involving the king and a rook. Movetext can include move numbers and PGN comments. Illegal moves are not allowed as moves, although they may be discussed inside commentary.

It can also contain NAGs, Numeric Annotation Glyphs, which are normalized assessments written as a dollar sign followed by a number, and RAVs, Recursive Annotation Variations, which are alternative lines inside parentheses. Each RAV begins from the position before the move it replaces and may contain its own annotations or nested variations.

The final element is one of four markers: 1-0 for a White win, 0-1 for a Black win, 1/2-1/2 for a draw, or an asterisk when the game is in progress, abandoned, or otherwise unresolved. It must match the Result value in the corresponding tag pair.