Lets play lawyer and save an innocent person in court.
As a lawyer, you must win over 12 jurors one by one (i.e. open 12 decks of cards and deal them according to the rules). If a next juror cannot be convinced, the floor is given to the prosecutor, who "shuffles your cards" and tries to complicate the task. Although sometimes it can even help you.
You win if all 12 jurors unanimously declare the defendant innocent.