In "The Cask of Amontillado," there are some similarities between Montresor, the narrator of Edgar Allan Poe's short story, and Fortunato.
One similarity is that they both considered themselves to be connoisseurs of wine.
"In painting and gemmary, Fortunato, like his countrymen, was a quack, but in the matter of old wines he was sincere. In this respect I did not differ from him materially--I was skillful in the Italian vintages myself, and bought largely whenever I could."
Fortunato and Montresor are also alike in social status. They are both noblemen, evidenced by their coats-of-arms and the fact that they call each other friend. People tended to socialize within their class at the time this story is set. Montresor invites Fortunato to his "palazzo," which is Italian for a palace.
Another similarity they have is that they are both prideful. Fortunato considers himself superior to Luchesi, saying Luchesi can't tell amontillado from common cooking sherry. He also proudly lords it over Montresor that he is a member of the Freemasons, and it is indicated that Montresor is not, since he doesn't recognize the gesticulations of Fortunato. Montresor is prideful in that he will not stand for Fortunato insulting him without exacting his revenge. The fact that his revenge is carefully thought out and heinous shows the depth of his pride and arrogance.
And finally, they are both attending carnival, which implies that they are culturally aware and interested in the social aspects of the time period in which they are living.