Answer:
Not to alter the past.
Step-by-step explanation:
- The common time travel rule that "A Sound of Thunder"" and "By His Bootstraps" is not to alter or change the past.
- Both stories had the same rule as any slight change in the past or even killing a mouse, as in "By His Bootstraps" , would have a negative effect on the future.
- Though history may not completely change by a time traveler’s actions, there are chances that they might disrupt the events of things in the future.