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.