Open file

	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

The e-file is an open file since there are no pawns on it. The rook can move to any square on the file (marked with crosses), uninhibited by pawns.

An open file in chess is a file with no pawns of either color on it.^[1] In the diagram, the e-file is an open file. An open file can provide a line of attack for a rook or queen. Having rooks or queens on open files or half-open files is considered advantageous, as it allows a player to attack more easily, since a rook or queen can move down the file to penetrate the opponent's position.

This article uses algebraic notation to describe chess moves.

^ According to Nimzowitsch, "A file is said to be open for the Rook when no pawn of his [own color] is in it." Elsewhere, "From the definition of an open file, it follows that a file will be opened by the disappearance of one of our own pawns." This defines what others call a half-open file.

[1] According to Nimzowitsch, "A file is said to be open for the Rook when no pawn of his [own color] is in it." Elsewhere, "From the definition of an open file, it follows that a file will be opened by the disappearance of one of our own pawns." This defines what others call a half-open file.

[1]