The protagonists of "The Cask of Amontillado" and "The Most Dangerous Game" are both men who follow their own designs. But, their greatest difference lies in their reason for killing. For, while Montresor's killing of Fortunato is a personal vendetta, General Zaroff feels nothing personal toward Rainsford; the man is merely used as an interesting and challenging prey for this most-jaded of men. And, as this "beast of prey"--as even Rainsford calls himself--the possible victim is keenly cognizant of his position; on the other hand, in Poe's story, Fortunato is unaware of his position as victim. Deluded by his own ego and by the flattery and manipulation of his professional jealousy of Luchesi by Montesor, Fortunato is unwittingly led to his capture by shackles in the catacombs and his death by being walled in.
Nonethless, it is true that Montesor does afford Fortunato some inkling that his intentions may be ulterior during the scene in which the word mason is punned and as Montesor suggests often that they turn back because of the niter and cold. Still, Montesor has never overtly made it known to Fortunato that he is the object of revenge as General Zaroff has made it known to Rainsford that he is prey for him. Montesor offers his victim no chance once he is confronted by death. However, Rainsford has the chance to confront his victimizer and slay him.
These two men both serve as apt antagonists, but their mentalities are quite different. While Montresor is bent on revenge and vindictiveness, Zaroff is merely a bloodthirsty hunter, whose one desire is to capture and kill "The Most Dangerous Game"-- man.
Rainsford finds himself the target of Zaroff's insane game, one where human prey must evade, elude, and ultimately kill his predator. On the other hand, Fortunato is totally oblivious to Montresor's malicious intents. He is led like a lamb to the slaughter, through the catacombs, and eventually to his own doom. The difference here lies in motive: Zaroff's is sadistic pleasure, while Montresor's is envious payback.