If you file a lawsuit and lose the case, you can appeal the decision to the next highest court, which is called the appellate court. Appellate lawyers often specialize in arguing appeals; that is, they specialize in arguing why the decision of the lower court was wrong (or why it was right, for the party that won). Appellate attorneys specialize in appeals because they understand the specific and detailed rules that must be followed. It is possible to lose an appeal on technicalities, even when the law is on your side. If you want to appeal the outcome of the trial court, or if you need to argue against another person's appeal, you should work with an appellate attorney.