Peremptory challenge is a right in jury selection for the parties to a court case to reject a certain number of potential jurors without having to give any reason. Other potential jurors may be challenged for cause, i.e. by giving a reason why they might be unable to reach a fair verdict.
Its use is controversial, as it has been used to undermine the balanced representation on a jury which would occur using random selection. It was first used in England, but in the 20th century its use was restricted and then abolished as being unfair. It remains in use in several other juristictions, and in some cases leads to extensive and expensive jury research, aimed at producing a favourable jury.