One of the best topics in "The Most Dangerous Game" is the conflict of Man vs. Man, or the struggle between two characters that defines the core of the story. Rainsford is captured by General Zaroff and made to play in his "game," the hunting of humans for sport. Rather than participate in the hunt as a hunter, Rainsford opts to be hunted as prey. The clash between Rainsford and Zaroff's hunting skills provides the suspense and the climax of the story.
Additionally, the difference between hunting for sport and hunting for necessity could be explored through Zaroff's entirely selfish actions -- he hunts only for sport, and chooses humans to provide a mental challenge -- and through Rainsford's pragmatic reactions -- he uses his hunting skills to fight back, killing because he knows he must to survive. If Rainsford played the game as Zaroff meant it to be played, he knows that he would die, so he instead chooses to alter the rules according to his knowledge of the hunt.