A motion is a request filed before the court that it issue a particular order or take a particular course of action. Most legal systems provide that early in a case, a defendant can file a motion to dismiss the plaintiff’s claims on grounds of legal insufficiency, a type of motion also sometimes called a ‘demurrer.’ To explain, if a plaintiff is bringing a claim that requires it to show factual elements a+b+c+d to succeed and the factual assertions made by the plaintiff support the existence of a+b, but not c or d, the case is incomplete and should be dismissed. Normally the court will offer the plaintiff the opportunity to re-file its claims, if it can, assert the missing elements. However, most civil procedure rules and rules of legal ethics and professional conduct provide that a lawyer may not file a complaint without at least a colourable reason to believe that he or she can prove the factual assertions it depends on.
Motions to dismiss can be based both on the asserted factual bases of the underlying claims or on issues such a jurisdiction. By contrast a summary judgment motion usually occurs later in the case, once evidence is before the court. In a summary judgment motion, the defendant argues that while the plaintiff is required to show elements a+b+c+d for its claim to succeed, the plaintiff has failed to advance evidence on which a reasonable person could find for example that c or d were present and the action would therefore necessarily fail. In such a case that specific issue or part of the plaintiffs claim does not proceed to trial.
In common law courts with juries, the usual principle is that the judge controls the law and juries make factual findings based on the evidence before them. However, after a jury has rendered a factual verdict, if the judge regards the conclusions of the jury as unfounded, the judge may set aside the factual findings, i.e., the verdict. In particular if for example a party needed to show factually a+b+c to succeed on a point in a case and the judge felt that the jury’s verdict had been reached despite a lack of adequate evidence of say fact b, the judge could set aside the verdict. This power is designed as a check on runaway or biased juries. Lawyers often refer to this motion and decision as a JNOV, an acronym for Judgement Non Obstante Verdicto or JNV, Judgment Notwithstanding the Verdict.