In "The Most Dangerous Game," what is an example of irony?

Rainsford, the protagonist, begins the story as a famous
hunter with no empathy for his animal prey. After falling overboard, he meets Zaroff,
who invites him on a hunt. When he discovers the nature of the hunted animal -- man --
he resists the idea. During his own hunt, as a prey animal, Rainsford uses his knowledge
of a hunter's mindset to set traps and ambushes. Rainsford's eventual success is a
result of his willingness to bend the rules; even Zaroff, at the end, acknowledges
Rainsford's win. The irony is that Rainsford, who refused to accept the concept of the
Game, must accept first his role as prey and then reverse the roles and be willing to
kill a reasoning man as hunter.