Final answer:
A certain number of challenges for excusing a prospective juror without giving a reason in a trial are known as peremptory challenges, which are part of the jury selection process upheld by the Sixth Amendment.
Step-by-step explanation:
The certain number of challenges given to the plaintiff and Defendant in a trial, for which no reason or cause need be given to excuse a prospective juror, is known as a peremptory challenge. The Sixth Amendment of the U.S. Constitution ensures the right to a fair and impartial jury, and as part of this process, both prosecution and defense are allowed to use peremptory challenges during jury selection.
These challenges permit both sides to exclude certain jurors without a need to state a reason, often forming a strategy to create a jury perceived as more favorable to their case. However, any exclusion based on race or sex may be challenged and is prohibited under the Equal Protection Clause of the Fourteenth Amendment.