Under what circumstance might a cross-appeal be necessary?

A cross-appeal is a procedural mechanism that allows a party who did not prevail in the original case to challenge aspects of the decision they find unfavorable while the other party is appealing. This is essential in maintaining a complete and coherent examination of the case on appeal.

In the context of the selected answer, it is necessary for a defendant to file a cross-appeal when they want to contest a specific part of the decision made against them, while the other party (usually the plaintiff) has also appealed. By doing so, both parties can comprehensively address the appeals process in one proceeding, rather than necessitating separate appeals that could prolong the resolution and create inconsistent judgments.

Other options are relevant but do not directly pertain to the need for a cross-appeal. For example, bias in judgment or new evidence might call for different types of legal motions or appeals based on procedural fairness or substantial justice, while a change in legal representation primarily relates to the right to legal counsel rather than the appeal process itself. Thus, the cross-appeal serves the specific function of allowing for a multifaceted review of the trial court's judgment among all parties involved.