The Honorable Zaroff. Despite the barbaric intent of General Zaroff's desire to hunt human beings, he still displays a sense of honor and chivalry that he must have maintained from his military days. When he announces that he plans to hunt Rainsford that night, Rainsford wonders what he can expect if the impossible happens--if he wins.
"I'll cheerfully acknowledge myself defeat if I do not find you by midnight of the third day," said General Zaroff. "My sloop will place you on the mainland near a town." The general read what Rainsford was thinking.
"Oh, you can trust me," said the Cossack. "I will give you my word as a gentleman and a sportsman..."
Rainsford probably does not believe Zaroff, but I had an inkling that the rules of the game would be even more important to the Cossack than the actual victor. Sure enough, when he is surprised in his bedroom by the very much alive Rainsford, Zaroff "made one of his deepest bows," and announces that Rainsford has "won the game." It is Rainsford who breaks the rules, claiming that he is "a beast at bay," and the hunt continues.
Rainsford the Soldier. Rainsford's war service is never directly discussed, but a single allusion suggests that he was also a World War I veteran.
Rainsford had dug himself in in France when a second's delay meant death.
It suggests that he was not just a killer of animals, but a former soldier who could defend himself and kill another man if necessary.
Rainsford the Killer. We don't know for certain that Rainsford killed Zaroff, but it can be inferred that he had reverted to a savage himself by the final line of the story:
He had never slept in a better bed, Rainsford decided.
How else could Rainsford had slept so comfortably if Zaroff had not been disposed of?