"A Sound of Thunder" by Ray Bradbury is a quick moving, suspenseful short story. Conflict adds tension to any short story, and this one is no exception. There are four types of conflict:
1. Man Vs. Man -- During their trip back in time, Eckels panics when he sees the dinosaur and steps off the path, a huge mistake that could alter time. Travis, the tour guide, is furious with Eckels and threatens to leave him back in the past. He states:
"Stay out of this!" Travis shook his hand away. "This fool nearly killed us. But it isn't that so much, no. It's his shoes! Look at them! He ran off the Path. That ruins us! We'll forfeit! Thousands of dollars of insurance! We guarantee no one leaves the Path. He left it. Oh, the fool! I'll have to report to the government. They might revoke our license to travel. Who knows what he's done to Time, to History!"
This Man Vs. Man conflict adds tension between the two main characters of the story and adds to the suspense the reader feels as to what they will find when they return to present day.
2. Man Vs. Nature -- This is the conflict that Eckels feels with the dinosaur he encounters in the past. It is huge - far bigger than he expected and he loses his nerve. Aside from the physical battle between the men and the dinosaur, this conflict also overlaps with Eckels internal conflict, man vs. self.
3. Man Vs. Society -- This conflict is what makes the novel interesting; it begins as a sort of backdrop, seemingly unimportant, but by the end of the novel, Eckels' worst fear comes true and Deutscher is President. At the beginning of the story, Eckels states:
"Makes you think, If the election had gone badly yesterday, I might be here now running away from the results. Thank God Keith won. He'll make a fine President of the United States." "Yes," said the man behind the desk.
"We're lucky. If Deutscher had gotten in, we'd have the worst kind of dictatorship. There's an anti everything man for you, a militarist, anti-Christ, anti-human, anti-intellectual. People called us up, you know, joking but not joking. Said if Deutscher became President they wanted to go live in 1492. Of course it's not our business to conduct Escapes, but to form Safaris. Anyway, Keith's President now.
This sets up another external conflict that reappears again at the end of the story.
4. Man Vs. Self -- This conflict is really the turning point of the story: Eckels loses his nerve and panics, veering off the path and rewriting history. When he sees the dinosaur, he states:
"Get me out of here," said Eckels. "It was never like this before. I was always sure I'd come through alive. I had good guides, good safaris, and safety. This time, I figured wrong. I've met my match and admit it. This is too much for me to get hold of."
He has a moment of realistic observation when he sees this dinosaur and is legitimately frightened. His veering off the path is what causes the change in the future.