Luft

	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

White needs to give his king luft to avoid a back rank checkmate. To do this, white can move either one of the two pawns next to his king.

Luft, the German word for "air" (sometimes also "space" or "breath"), is used by some chess writers and commentators to denote a space or square left by a pawn move into which a castled king may move, especially such a space made with the intention of avoiding a back rank checkmate. A move leaving such a space is often said to "give the king some luft".

A simplified example is seen to the right. Black is threatening checkmate with the simple 1...Re1# and White must deal with this threat. The right thing to do is to give the king some luft by moving a pawn on the g or h file: 1.g3, 1.g4, 1.h3, and 1.h4 will all avoid immediate checkmate. After each, 1...Re1+ can be simply met with 2.Kg2 or 2.Kh2.

	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

Black has a weak luft, White has a strong luft (Evans, 1958). Black dots indicate holes.

It is usually better to move the h-pawn (or the a-pawn if the king is on the queenside) because moving the f-pawn can weaken the king's position and moving the g-pawn creates holes at f3 and h3 (or f6 and h6 for Black on the kingside). In the diagram, Black has a weak luft because of the holes on a6 and c6; White has a strong luft, without holes (Evans 1958:52-53).

A luft square for a king can be "plugged up" by placing the square in check (under possible attack) by an opposing piece such as a bishop, queen, pawn, or possibly knight. Then, the said king cannot move into the luft square in check, leaving it still vulnerable to a back rank mate.

Read more:

• Flight square
• Pawn structure