Rule 12.Defenses and objections: when and how presented; motion for judgment on the pleadings; consolidating motions; waiving defenses; hearings before trial
Title III: Pleadings; Motions; Scheduling · Last amended July 1, 2018 · Last verified July 14, 2026
Full Text of Rule 12
Amendment History
(Adopted March 1, 2016, effective July 1, 2016; amended September 9, 2016, effective September 9, 2016; amended April 25, 2018, effective July 1, 2018.)
Plain-English Summary
Rule 12 starts with the clock: a defendant generally has 21 days after service of the summons and complaint to answer, and similar 21-day windows apply to answering a counterclaim, crossclaim, or a court-ordered reply. Filing certain motions under this rule resets that clock, giving the responding party 14 days after the court rules or after a more definite statement is served.
The heart of the rule is subsection (b), which lists eight defenses a party can raise by motion instead of waiting to plead them: lack of subject-matter jurisdiction, lack of personal jurisdiction, improper venue, insufficient process, insufficient service of process, failure to state a claim upon which relief can be granted, failure to join a required party, and, distinctly under Idaho practice, another action already pending between the same parties over the same cause. That last ground has no federal counterpart and lets a party point the court to a duplicate lawsuit already underway. A motion to dismiss for failure to state a claim, and a post-pleadings motion for judgment on the pleadings, both convert into summary judgment motions if the parties put outside evidence before the court and the court does not exclude it.
The rule also polices timing and waiver. Most Rule 12(b) defenses have to be raised in a party's first responsive motion or pleading or they are lost, though failure to state a claim, failure to join a required party, the pending-action defense, and lack of subject-matter jurisdiction get more forgiving treatment and can surface later, even at trial for some of them. A party generally cannot bring a second Rule 12 motion raising a defense that was available but left out of the first one. Separate provisions cover motions for a more definite statement when a pleading is too vague to answer, and motions to strike improper material from a pleading, and the rule directs that any of the listed defenses, if a party asks, be resolved before trial rather than saved for trial itself.
Frequently Asked Questions
What is a 12(b)(6) motion to dismiss for failure to state a claim?
It is a motion asking the court to dismiss a claim because, even taking the alleged facts as true, they do not add up to a legal claim the court can grant relief on. Rule 12(b)(6) lists this among the defenses a party can raise by motion instead of waiting to answer.
How is an improper venue motion different from a personal jurisdiction motion?
They address different problems. Improper venue under Rule 12(b)(3) argues the case was filed in the wrong court location even though the court could otherwise hear it; lack of personal jurisdiction under Rule 12(b)(2) argues the court has no authority over the particular defendant at all. Both must generally be raised in a party's first motion or pleading or they are waived, per subsection (h) and Rule 40.1.
What does "another action pending between the same parties for the same cause" mean, and why is it in Idaho's rule but not the federal rule?
This is Rule 12(b)(8), a ground unique to Idaho practice with no equivalent in the Federal Rules of Civil Procedure. It lets a party move to dismiss when the same parties are already litigating the same underlying dispute in another pending case, avoiding duplicate lawsuits proceeding side by side.
Can I bring a second motion under Rule 12 if I forgot a defense the first time?
Generally no. Subsection (g) bars a party from making a later Rule 12 motion to raise a defense that was available but omitted from an earlier one, with limited exceptions preserved in subsection (h) for things like failure to state a claim, failure to join a required party, subject-matter jurisdiction, and the pending-action defense.
What happens if I attach outside evidence to a motion to dismiss?
Under Rule 12(d), if the parties present matters outside the pleadings on a Rule 12(b)(6) or 12(c) motion and the court does not exclude that material, the motion converts into a motion for summary judgment under Rule 56, and everyone must get a fair chance to respond to that outside material.