## Introduction

A counterclaim is a claim for relief brought by a party after an opposing party has sued them. In plain terms, if you’re sued, you can sue back in the same case. Counterclaims help courts and parties resolve related disputes in one proceeding, cutting time and cost. In federal court, counterclaims are governed by Federal Rule of Civil Procedure 13, with similar rules in many states.

This guide explains what a counterclaim is, when you must file one, how to plead it, and common pitfalls that can create waiver or jurisdiction problems. It’s written for a U.S. audience and uses federal rules as a baseline, noting where state law may differ.

## What You’ll Learn

- What a counterclaim is and who can file one
- The difference between compulsory and permissive counterclaims under Rule 13
- Deadlines, pleading standards, and reply requirements
- How jurisdiction works for counterclaims (federal question, diversity, supplemental)
- Practical drafting and strategy tips to avoid waiver and keep your case on track
- How counterclaims compare with crossclaims, setoff, recoupment, and affirmative defenses
- Realistic examples showing how counterclaims play out in court

## Core Concepts

### What Is a Counterclaim?

- A counterclaim is a claim for relief asserted by a defending party against the party who sued them.
- It’s included in the same pleading that responds to the complaint (usually the answer).
- Relief sought can be damages, declaratory relief, or an injunction, and it can exceed or differ from the relief sought in the complaint.
- Any party against whom a claim is asserted may counterclaim, including original defendants and, in third-party practice, third-party defendants against third-party plaintiffs.

Key features:

- Keeps related disputes in a single lawsuit
- Avoids inconsistent outcomes across separate cases
- Can change the posture of the case by putting the original plaintiff on the defensive

### Compulsory vs. Permissive Counterclaims

Rule 13 draws a line between “must file now” and “may file now”:

Compulsory counterclaims (Rule 13(a))

- Arise out of the same transaction or occurrence as the opposing party’s claim (often assessed using a “logical relationship” test).
- Must be stated in the responsive pleading, or you may be barred from bringing them later.
- Exceptions:
  - If the claim needs a person the court can’t get jurisdiction over
  - If the claim is already the subject of another pending action

Permissive counterclaims (Rule 13(b))

- Do not arise from the same transaction or occurrence.
- May be brought in the same case, but usually require an independent basis for subject-matter jurisdiction in federal court (federal question or diversity, including amount in controversy).

Practical takeaway:

- If your claim is closely connected to the plaintiff’s claim, treat it as compulsory and include it in your answer to avoid waiver.
- If it’s unrelated, assess whether you have an independent jurisdictional basis or should file separately in state court.

### Pleading and Procedure Basics

- Timing to assert: File counterclaims with your answer, typically within 21 days after service of the complaint in federal court (Rule 12(a)), unless a different deadline applies (e.g., waiver of service, the United States as a party).
- Pleading standard: State a short and plain statement showing entitlement to relief (Rule 8). Claims sounding in fraud or mistake require particularity (Rule 9(b)).
- Reply required: The opposing party must serve a reply to a counterclaim within 21 days after service, unless the court orders otherwise (Rules 7(a)(3), 12(a)(1)(B)).
- Amendments: You may amend as a matter of course within the Rule 15(a)(1) window; after that, you need consent or leave of court. Supplemental pleadings under Rule 15(d) can add claims that matured after the original pleading.
- Relation back: Amended counterclaims may relate back under Rule 15(c) if they arise out of the same conduct, transaction, or occurrence. This can be important for statute of limitations issues; check circuit and state authority.
- Sanctions: Rule 11 applies to counterclaims. Ensure factual and legal support or risk sanctions.

### Jurisdiction and Venue Considerations

- Subject-matter jurisdiction:
  - Compulsory counterclaims typically fall within supplemental jurisdiction if they share a common nucleus of operative fact with the main claim (28 U.S.C. § 1367).
  - Permissive counterclaims usually require an independent jurisdictional basis (federal question or diversity, including amount in controversy).
- Personal jurisdiction and venue: The court must have personal jurisdiction over parties and venue must be proper. Adding parties via counterclaims may raise new jurisdiction and venue questions.
- Sovereign immunity: Rule 13(d) clarifies that the rules don’t expand the right to assert claims against the United States; you need a waiver of sovereign immunity.

### Counterclaim vs. Crossclaim, Setoff, Recoupment, and Affirmative Defenses

- Crossclaim (Rule 13(g)): A claim against a co-party (e.g., one defendant suing another defendant). Not the same as a counterclaim, which targets an opposing party.
- Setoff: A defensive claim that reduces or cancels the plaintiff’s recovery based on a separate transaction. Often requires an independent jurisdictional basis in federal court if asserted affirmatively.
- Recoupment: A defensive claim arising from the same transaction as the plaintiff’s claim, used to reduce the plaintiff’s recovery. Typically not barred by limitations if asserted purely defensively.
- Affirmative defenses: Legal reasons the plaintiff should not recover (e.g., statute of limitations, waiver). Not claims for relief and do not require jurisdictional bases.

## Key Examples or Case Studies

Example 1: Contract dispute (home renovation)

- A contractor sues a homeowner for unpaid invoices on a kitchen remodel.
- The homeowner files a counterclaim alleging negligent workmanship that caused property damage and additional repair costs.
- Outcome possibilities:
  - The court finds both claims valid, calculates each side’s damages, and offsets the amounts.
  - The counterclaim defeats the contractor’s claim entirely if the damages exceed the amount owed.

Example 2: Personal injury (car accident)

- The plaintiff alleges the defendant rear-ended their vehicle and sues for medical expenses and lost wages.
- The defendant files a counterclaim, arguing the plaintiff suddenly and unsafely changed lanes, causing the crash, and seeks their own damages.
- Why it matters:
  - Comparative fault and competing claims can be addressed together.
  - Insurance carriers for both sides are involved in one case, streamlining resolution.

Case study: Jones v. Smith (hypothetical)

- Jones sues Smith for breach of contract over late delivery of components.
- Smith counterclaims that Jones first breached by failing to provide required specifications on time, causing delays and lost profits.
- Result: The court considers both claims together, determines who breached first, and awards damages accordingly. Smith’s counterclaim would likely be compulsory because it arises from the same project and delays.

Case study: Brown v. Davis (hypothetical)

- Brown sues Davis for defamation based on online statements.
- Davis counterclaims that Brown previously made false statements causing reputational harm and lost business.
- Court approach: Both claims proceed if they meet pleading standards. The court may address privilege, truth, and damages for each side within the same trial.

## Practical Applications

- Decide early if your claim is compulsory:
  - Ask whether your claim arises from the same transaction or occurrence as the complaint.
  - If yes, include it in your answer to avoid waiver and claim preclusion later.

- Check jurisdiction before filing:
  - Compulsory counterclaims usually fit under supplemental jurisdiction.
  - Permissive counterclaims often need federal question or diversity jurisdiction. If not available, consider filing separately in state court.

- Mind the clock:
  - Calendar the answer deadline (often 21 days after service in federal court).
  - Calendar the reply deadline for any counterclaims you receive (21 days after service).
  - Track statutes of limitations and use Rule 15(c) relation back where it applies.

- Draft with purpose:
  - Use clear, factual allegations supporting each element.
  - Include the legal basis (contract, negligence, statutory claim) and the relief sought.
  - If alleging fraud or mistake, plead with particularity (Rule 9(b)).
  - Consider a jury demand (Rule 38) if you want one.

- Consider motions practice:
  - Move to dismiss an opponent’s counterclaim under Rule 12(b)(6) if it fails to state a claim.
  - Use Rule 12(f) to strike redundant, immaterial, or scandalous matter.
  - If you need more detail, consider a Rule 12(e) motion for a more definite statement.

- Coordinate evidence and discovery:
  - Identify documents, witnesses, and expert needs that support both your defense and your counterclaim.
  - Serve discovery tailored to damages and causation for both sides’ claims.

- Address insurance and indemnity:
  - Notify carriers promptly if coverage may apply.
  - Review contracts for indemnity, defense, or limitation-of-liability clauses that affect your counterclaim.

- Plan for settlement:
  - Use a well-supported counterclaim to improve your bargaining position.
  - Consider early mediation after exchanging key information.

- Watch special defendants:
  - Claims against government entities may require a statutory waiver and prior notice.
  - Be mindful of state-specific pre-suit requirements (e.g., medical malpractice certificates).

- Maintain professionalism:
  - Rule 11 applies. Don’t assert counterclaims without a factual basis and a good-faith legal argument.

## Summary Checklist

- Identify whether your counterclaim is compulsory or permissive under Rule 13
- Confirm subject-matter, personal jurisdiction, and venue
- Meet deadlines: answer and counterclaim, reply to counterclaim
- Satisfy pleading standards (Rule 8; Rule 9(b) when applicable)
- Include a clear demand for relief and, if desired, a jury demand
- Use Rule 15 for amendments and supplemental pleadings
- Evaluate setoff/recoupment and how they interact with your claims
- Consider motions to dismiss or strike weak counterclaims you receive
- Preserve evidence and coordinate discovery on both sides’ claims
- Check for sovereign immunity and notice requirements when suing public entities

## Quick Reference

| Topic                      | Rule/Authority      | Key Point                                                                        |
| -------------------------- | ------------------- | -------------------------------------------------------------------------------- |
| Compulsory counterclaim    | FRCP 13(a)          | Same transaction or occurrence; must be pled or risk waiver/claim preclusion.    |
| Permissive counterclaim    | FRCP 13(b)          | Unrelated claims; often need independent federal jurisdiction.                   |
| Pleading standard          | FRCP 8(a); 9(b)     | Short and plain statement; fraud/mistake require particularity.                  |
| Answer and reply deadlines | FRCP 12(a); 7(a)(3) | Answer (often 21 days); reply to a counterclaim due 21 days after service.       |
| Supplemental jurisdiction  | 28 U.S.C. § 1367    | Covers claims sharing a common nucleus of operative fact with the main claim.    |
| Amend/supplement pleadings | FRCP 15(a), 15(d)   | Amend as of course within set windows; supplement matured/after-acquired claims. |
| Claims vs. U.S.            | FRCP 13(d)          | Rules don’t expand the right to sue the U.S.; a statutory waiver is required.    |

Counterclaims in U.S. Civil Litigation: Types, Rules, and Examples