The best example of conflict leading to change involves Rainsford's personal philosophy. At the beginning of the story, as a hunter, Rainsford believes in survival of the fittest and the right of the strong to hunt the weak:
"The world is made up of two classes--the hunters and the huntees. Luckily, you and I are hunters."
When he meets Zaroff, who shares that viewpoint, he becomes disgusted with the obvious conclusion of that philosophy: strong men should have the right to hunt the weak. Rainsford believes that there is a human moral code that should prevent man preying on man; Zaroff believes that all men are animals and so have the right to prey on each other.
"The weak of the world were put here to give the strong pleasure. I am strong. Why should I not use my gift?"
Although he refuses to accept Zaroff's philosophy, Rainsford is forced to act as an animal when he is turned out as prey, and finally must come to terms with his own survival versus what he feels is a moral code. At the end of the story, he returns to Zaroff's room, and although Zaroff concedes Rainsford's victory, Rainsford insists on fighting him:
"I congratulate you," he said. "You have won the game."
Rainsford did not smile. "I am still a beast at bay," he said, in a low, hoarse voice. "Get ready, General Zaroff."
(Connell, "The Most Dangerous Game," classicreader.com)
Although Rainsford had rejected the idea of "cold-blooded murder" in the matter of hunting other men, he knows that Zaroff cannot allow him to live; therefore, Rainsford's own survival is of more importance than his moral code, and so he kills Zaroff to keep himself alive.