Despite the similarities, oppositions differ in some significant ways from lawsuits. Perhaps the biggest difference is that there is no live trial. The Board reviews the transcripts of those depositions, along with whatever other evidence the parties have submitted, to reach its conclusion. The attorneys file trial briefs setting forth their arguments on the facts and law, and may request an oral hearing to present their arguments. Oppositions also differ from lawsuits in the scope of the issues.
Oppositions normally focus narrowly on the issue of likelihood of confusion.
Another significant issue may be whether the opposer has prior rights in the mark. Because the Board has no power to award injunctive relief, damages, costs, or attorneys' fees, a successful opposition does not prevent the applicant from using the mark, and the amount of such items as damages and profits is not at issue. As a result of the narrowed scope, an opposition is normally less costly to pursue than a lawsuit would be. The presumption of validity of a registered mark could make it more difficult for the prior owner to prevail in an infringement lawsuit. Even a minor competitor will often decide to choose a more distinct mark, or simply forgo registration, rather than defend an opposition.