.PGN4 Bestandsextensie

The PGN4 format extends standard PGN to handle the larger board, four players, additional piece colors, and move notation required by four-player chess. Players, chess analysts, developers, and variant-chess enthusiasts may use PGN4 files to save games, review move sequences, share matches, or analyze four-player chess positions with compatible software. Notably, Chess.com uses the format to store four-player chess games played on its platform and includes features, such as Variant, RuleVariants, StartFen4, and player-specific tags.

Since PGN4 is based on PGN, its overall structure resembles a normal chess game record, but its notation includes information that standard two-player PGN does not need. For example, the format can represent moves on a larger board and identify moves made by each of the four players. Software that supports only standard PGN may not interpret these additional elements correctly.

You can open PGN4 files with software that supports four-player chess notation, such as GammaDeltaII 4PlayerChess, which can load and save Chess.com-compatible PGN4 games on Windows, macOS, and Linux. Chess.com can also load PGN4 files directly in its Four Player Chess/Variants interface.

Since PGN4 files are plain text, you can also view or edit them with any text editor, although specialized chess software is required to display the game on a board and step through the moves correctly.