Chess/Tempo

A tempo, or tempi in plural, is used in each game to calculate the developing moves in the opening or a measure of time.

Tempi in the opening are related to the moves in the opening.

	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

Knight attacking a pawn

You gain tempi when you attack a piece with a developing move and the opponent can not defend the piece with a developing move, so she or he loses tempi.

	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

Knight attacking the queen

You lose tempi when your opponent attacks your piece with a developing movement and you cannot defend that piece with a developing movement, so you have to spend one tempo by retreating your piece or defending it (with a non developing move).