Suicide is illegal in Weiqi. In other words , a player cannot play the triangle-marked stone as shown in the diagram below.

Consider the following diagram,

By placing the triangle-marked seed , black can capture white because before this the 2 white stone A and B are in atari .

In some special case , seeds can never be captured because it has two or more eyes , as shown in the figure above . Let say black wants to capture all the white seed , so he would place a black seed (marked by a triangle) inside the eye to cover one liberty . However , once the seed is placed inside , it is to be removed at that instant, because the black seed has no liberty itself , ( i.e. it dies immediately ). In this way , the white seeds can never be captured because black seed cannot be placed into either of the eyes.

rule 5: the survival of a seed

rule 7: ko