Motions to dismiss usually come in the early stages of a civil litigation. Rule 12 of the Federal Rules of Civil Procedure provides that certain affirmative defenses in federal civil cases can be brought as motions to dismiss. States have similar rules.
The idea behind a motion to dismiss is that there is something faulty in the plaintiff’s case that should prevent the case from continuing.
For example, let’s say a plaintiff sues a defendant in federal court for committing fraud. And the complaint only describes the fraud in very general terms. However, Rule 9 requires the plaintiff to allege the circumstances of the fraud with specificity. Under these circumstances, the defendant could move the court to dismiss the claim for failure to state a claim.
Courts often dismiss a claim or case without prejudice. When a court dismisses a case without prejudice, the plaintiff will have an opportunity to fix whatever problem caused the court to dismiss the case. In our example above, the court might allow the plaintiff an opportunity to add more facts to her fraud complaint to meet the requirements of Rule 9.