A for cause challenge is a legal mechanism used during jury selection that allows a party to request the dismissal of a potential juror based on a specific reason, such as bias or inability to be impartial. This type of challenge requires the party to provide a valid reason for their objection, which can be assessed by the judge. Unlike peremptory challenges, there is no limit to the number of for cause challenges that can be made, making it a crucial tool for ensuring a fair trial.