In "The Sniper", what does the sniper do to trick his enemy?
In "The Sniper", the titular character is essentially trapped on a rooftop by another sniper; he is wounded and therefore unable to use his rifle to defend himself, nor can he move without being seen and shot at, nor can he stay on the rooftop until dawn, when things will only be worse and his wound may kill him. He is forced to resort to trickery in order to put his opponent on the defensive and thereby escape.
The sniper tricks his enemy by placing his hat on the end of his rifle and raising it above the parapets of the rooftop just enough to be seen. When the hat is shot, the sniper pretends to die, throwing his useless rifle off the rooftop in an effort to make the scene more convincing. This works, as the enemy sniper stands up and reveals himself, thinking that he's hit his mark and killed the titular sniper. The sniper uses this opportunity to shoot his opponent with his revolver, thereby killing him and securing an escape from the rooftop.
In this story, the sniper must trick his enemy so that he can safely exit the roof of the building. Remember that he is injured because the enemy has shot him in the forearm, and he has only a revolver to help him escape.
The sniper, therefore, develops a plan. First of all, he removes his cap and places it over the end of his rifle to make it look like the silhouette of a man. He then raises the rifle so that the enemy can see it. The enemy, believing that the rifle is the sniper, fires and hits the cap. To make this ruse look authentic, the sniper allows the rifle and cap to slowly fall to the ground.
The enemy now believes that he has killed the sniper, and he moves out of the darkness and between two chimney pots. The sniper now takes aim with his revolver and shoots at the enemy. His shot is successful; the enemy is killed and falls to the ground below, enabling the sniper to escape.