FRCP Rule 12(b) pertains to pretrial motions, and 12(b)(6) specifically deals with motions to dismiss for failure to state a claim upon which relief can be granted.

As a practical matter, Rule 12(b)(6) motions are rarely successful, and when they are, their success usually has more to do with the judge than the law. Nevertheless, they appear regularly in law school civil procedure exams (and bar exam civil procedure questions), so it’s important to be aware of them.

“Failure to state a claim upon which relief can be granted” can mean a number of things, all of which have to do with what is stated in a complaint.

Recognizing this, it is vital to include every fact that could in any way be relevant to give the court as complete a picture as possible.

Even if you have perfectly pleaded the elements of a given cause of action and included a complete and detailed set of facts, the Rule 12(b)(6) motion could succeed nonetheless. Although less commonly the reason for the success of such a motion, the court could decide that the pleaded cause of action isn’t recognized by the law.

Practically speaking, the judge would usually give the plaintiff leave to amend if a legal cause of action was apparent from the facts, but the 12(b)(6) motion would still technically be successful.