When a case goes to trial, odds are one or both of the parties will be unhappy
When two parties take a case all the way through trial, obtaining a verdict from a judge or jury, it's safe to assume that they don't agree on the facts and legal issues that were the subject of their litigation. Even if they agree on everything except the amount of damages to be awarded, their disagreement as to the amount of damages will be big enough that they chose to incur the cost and effort of trial to try to achieve an outcome more favorable than the other side believed to be just and fair.
If a party is unhappy with resolution of a personal injury case or other lawsuit, they have a number of options for seeking relief from the verdict.
A petition for a new trial asks that the trial court set aside the verdict issued in the case, and order that an entirely new trial be conducted. These petitions are rarely granted, and the denial of a petition for a new trial is usually upheld on appeal.
When granted, the grant of a new trial is usually based on the trial court's finding of serious misconduct on the part of the other party or opposing counsel, or based upon compelling evidence of juror bias.
A claim for additur alleges that the award of damages received was inadequate, and that the award should be increased by the judge. Due to the nature of this remedy, additur is typically a remedy requested by the plaintiff.
In a request for remittitur, a party to a lawsuit alleges that the award of damages to the plaintiff was excessive, and that the award should be reduced by the judge. Remittitur is a remedy typically requested by the defendant
An appeal is a petition for review to a higher court, to have that court examine the lower court proceedings for error which affected the outcome of the case. The appellate court reviews the record of the lower court proceedings, typically including the documents filed with the court, transcripts of court proceedings, and exhibits that were admitted into evidence, as well as briefs from the parties in which they describe the legal and factual grounds for either affirming or reversing the trial court's decision. The appellate court looks for significant error in the lower court proceedings.
An appeal is not a retrial of the case and, after the final resolution of a case before the trial court, it is at best difficult to introduce new evidence into the record to be reviewed on appeal.
Even if an appellate court finds that error has occurred, an appellate court may uphold the verdict if it finds that the error did not affect the outcome of the case, declaring the mistake to be "harmless error".
An appeal may be analogized to allowing the coaches from a football game specify various points in the game where the referee either failed to act on the other team's misconduct, or made a bad ruling. Under this analogy, the appellate court would first determine if the error was properly preserved for appellate review (for example, declining to review any alleged error where the coaches did not object to the referee at the time the error was made), and granting relief only if it believes that the net effect of errors it deems proved would have changed the outcome of the game.
Sometimes a judge will use its power to order a new trial, or to grant additur or remittitur, in order to press the parties into a post-verdict settlement of their case. For example, faced with a large verdict that the trial court believes is excessive, the trial court might indicate to the plaintiff that it is inclined to grant remittitur in a particular amount, or to order a new trial if that amount is not acceptable to the plaintiff.
A trial court might also use the threat of a potential order for a new trial to encourage a party to enter into a final settlement of the case on terms less favorable than the jury verdict.