How does the narrator lure Fortunato to his death?
One word--pride. Fortunato has apparently slighted Montressor (the narrator) to the point where he feels must take the ultimate revenge. He says there have been a "thousand injuries" which he has overlooked; but Fortunato insulted him, an act which could not go unpunished. The plan is simple, devious, and cruel. Montressor will lure the offender to the catacombs at his palazzo (the underground burial place for his dead ancestors) and then bury him alive.
But, this plan only works if he is able to lure Fortunato to his vaults. Montressor is apparently a student of human nature, and he uses his knowledge to carry out his plan. The story takes place during Carnival, festivities similar to Mardi Gras. He tells his servants he will be gone until the morning but they are NOT to leave--knowing full well they will go join the festivities once they know he is gone. Thus, an empty palazzo.
Next, Montressor finds the slightly drunk Fortunato and tells him he has bought a large quantity (a full pipe) of Amontillado. This is unlikely, since it's the middle of Carnival, and both men express their doubts as to the authenticity of the wine. Montressor has studied his victim and begins to set the trap, appealing to Fortunato's pride in being the only true connoisseur of wine.
Montressor invites him to come and be the judge, which he rather reluctantly agrees to do--as he has a bit of a cold and he'd rather be part of the festivites. Each time Fortunato appears to hesitate or falter, Montressor invokes the name of a rival, Luchesi, to lure him back. When Fortunato insists on tasting the amontillado, Montressor says, "My friend, no; I will not impose upon your good nature. I perceive you have an engagement. Luchesi--" The implication, of course, is that Luchesi would be able to do the job just as well. Each time the name is invoked, Fortunato is even more adamant that he be taken to the wine cellar to see for himself. "As for Luchesi," says Fortunato, "he cannot distinguish between Sherry and Amontillado."
Thus it continues...all the way down to the catacombs of the palazzo. Montressor says Fortunato should turn back because it's damp and he doesn't want his friend to catch pneumonia, and Fortunato says he is stronger than that. Pride again. Montressor offers to save him the trouble and get Luchesi, and Fortunato is even more adamant about going. Even at the end, Montressor acts like a caring friend, unwilling to have Fortunato harmed or injured in any way, while Fortunato nearly forces his way into his own grave.
The plan was just too easy. It hinged on the knowledge the narrator had of Fortunato's pride and the consistency with which he used that pride against his enemy. Montressor's definition of revenge is that he must not be punished for his act of avenging and the "avenger must make himself felt as such to him who has done the wrong." The great irony, of course, is that Fortunato did not, even at the end, understand why Montressor would do such a thing to him--calling into question both the insult by Fortunato and the excessive pride of his murderer.
The narrator in this story is a man named Montressor who hates Fortunato. He lures Fortunato to his death by playing on Fortunato's vanity.
What he tells Fortunato is that he (Montressor) has this new pipe of wine. He thinks that it is an amontillado. But he tells Fortunato that he is not sure. Fortunato is very proud of his knowledge of wines and so he wants to come and see whether the wine really is amontillado.
Along the way, Montressor plays on Fortunato's pride and competitiveness by saying he can get another man to come and assess the wine just as well. He says Fortunato is too sick and should go home. This makes Fortunato want to go even more.