How does Montresor get Fortunato to come with him to his vaults in "The Cask of Amontillado"?
Montresor entices Fortunato to accompany him on the pretext of desiring that Fortunato taste and confirm the quality of his Amontillado, dry sherry in a new cask he has recently purchased. He manipulates Fortunato by playing upon his professional rivalry with Luchesi.
Montresor has planned his revenge against Fortunato for "[T]he thousand injuries" that he has suffered. He has decided that he will lure Fortunato into the Montresor family vaults on the pretext of having him taste some Amontillado in order to confirm for him that it is truly dry and thus of especially high quality. He tells Fortunato:
"I have my doubts...and I was silly enough to pay the full Amontillado price without consulting you in the matter. You were not to be found, and I was fearful of losing a bargain."
Then, Montresor plays upon Fortunato's rivalry with Luchesi:
"If you are engaged, I am on my way to Luchesi. If anyone has a critical turn, it is he. He will tell me—"
"Luchesi cannot tell Amontillado from sherry." [says Fortunato]
"And yet some fools will have it that his taste is a match for your own."
This remark about his rival arouses Fortunato's desire to be the first to taste the Amontillado. Therefore, he urges Montresor to take him to the vaults so that he can boast of being the connoisseur who has first verified the quality of the Amontillado. Montresor, who previously dismissed all his servants to eliminate any risk of his actions being witnessed, then leads the unsteady Fortunato into the damp, niter-filled rooms. As they go deeper into the catacombs, the devious Montresor feigns concern for his "friend." In this way, Montresor follows his plan of revenge in which he can "punish with impunity."
It is stated before we even meet the characters that Fortunato is a wine connoisseur, and Montresor makes use of that fact to bring about Fortunato's death. He claims to have a pipe (a large barrel) of Amontillado, a very specific type of sherry, which is the first enticement. Then, Montresor says he will ask another man, Luchesi, whether or not it is actually Amontillado and not some random sherry; this serves as the second enticement, taunting Fortunato with the supposed expertise of another man. Fortunato takes the bait, claiming that Luchesi is not good enough to determine whether or not Montresor actually has a cask of Amontillado, so he himself would go and test it. Montresor pretends to decline, saying that Fortunato's health is not good enough to go down into the cellar, and he does that multiple times on their journey, but each time Fortunato states that he is fine and they should keep going. He is clearly very excited about the Amontillado, which means that Montresor made a good decision in using it as the bait. So, in the end, Montresor makes Fortunato think that it was his own idea to go into the vaults to test the cask of Amontillado.