Miai in Go are, in the simplest terms, a pair of vacant points on the board that are equivalent in terms of value. For example, if Black plays at A, White can play at B and suffer no disadvantage from the exchange.

This occurs often. With respect to a group's development or survival, pairs of points are frequently seen, such that if one player occupies one of them, his opponent will occupy the other. Miai can be seen in the fuseki stage on a large scale, or in a simple life and death problem, such as a straight four-space eye. This shape is alive because of its two central points a and b: if White plays b, Black can answer with a and vice versa.