A lawsuit is started by filing by a Complaint. The political party filing the Ailment is called the Plaintiff. In certain cases, a Plaintiff may make up one's mind to change his initial Complaint. There are many possible grounds that a Plaintiff may change or "amend" the Ailment (ie. the find of new evidence, a alteration in law, or even correcting a simple mistake). Federal Soldier Courts have got specific regulations for amending a Complaint. A Plaintiff may amend her Ailment once any clip before an Answer or "responsive pleading" is served. Fed. R. Civ. P.15(a). However, if the amendment is sought after the Answer is filed, the Plaintiff must either obtain (i) written consent from the opponent political party or (ii) permission from the Court.
Fortunately, that permission or "leave", as it is referred to in the rules, is usually freely given. In fact, under the rules, it would be inappropriate for the Court to deny the petition so long as there have been no not due delay, bad faith, or dilatory motivation on the portion of the movant, nor not due bias to the non-moving party. An illustration of "undue prejudice" would be if the Court concluded that the Plaintiff was seeking to amend the Ailment merely to detain the trial or add claims that the suspect would not have got got clip to prove in discovery.
Federal Courts have recognized the generous criterion in Rule 15 (a). In fact the United States Supreme Court have declared that the intent of this policy is primarily because the Courts prefer giving a Plaintiff the chance to "test his claim on the merits" Foman v. Davis, 371 U.S. 178, 182 (1962). In other words, a political party should be given his "day in Court", rather than limiting Plaintiffs claims through overly restrictive pleading rules.