Concept
Transaction or Occurrence
Compulsory counterclaim
Transaction or Occurrence
The compulsory counterclaim duty turns on one linking phrase in clause (A) of Rule 13(a)(1): the pleader's claim must arise out of the transaction or occurrence that is the subject matter of the opposing party's claim.1 A transaction is a set of dealings between parties, such as a contract and its performance, and an occurrence is an event, such as a collision or a fire, so the two words together reach claims that grow out of agreements and claims that grow out of accidents. The link matters because it sorts a defendant's claims into the two categories already described: a claim with the link must be pleaded or it is lost, and a claim without it may be pleaded or saved for another day.
The rule never says how close the connection must be. Read narrowly, the phrase would cover only claims resting on the identical event the plaintiff sued about; read broadly, it would cover almost any dispute between the same parties. A defendant who guesses wrong on the narrow side forfeits a claim by leaving it out, so the courts had to supply a definition the text withholds. The first subsection below begins with Moore v. New York Cotton Exchange, the Supreme Court decision from which lower courts trace the modern approach.
From that starting point the lower courts developed several tests. Each asks a different question about the same two claims: whether they raise largely the same issues of fact and law, whether substantially the same evidence will support or refute both, whether a later suit on the counterclaim would be barred by res judicata, and whether the counterclaim bears a logical relationship to the opposing claim. The tests overlap, and courts often consult more than one, but the logical-relationship test has become the dominant standard. The subsections below take the tests in turn and then apply them to decided cases. Every test is a way of answering a single question: are the two claims related closely enough that separate lawsuits would repeat the same facts?
Moore's Flexible Transaction
Rule 13(a)(1)(A) makes a counterclaim compulsory when it arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, yet it never says how closely related two sets of events must be.2 The working answer comes from Moore v. New York Cotton Exchange, a 1926 decision construing the federal equity rule that preceded Rule 13(a). That rule divided counterclaims into two classes: one “arising out of the transaction which is the subject matter of the suit,” which must be pleaded, and another that might be the subject of an independent suit in equity, which the defendant could bring or not as it chose.3 Later courts carried Moore's language into the Federal Rules, where it remains the most widely followed definition of the phrase.4 Every later test in this chapter is an attempt to apply or sharpen what Moore said, so the decision deserves a close reading.
The plaintiff in Moore sued the exchange over its refusal to furnish price quotations. The exchange counterclaimed that the plaintiff was nonetheless obtaining the quotations by stealth, and it asked the court to enjoin the practice.5 The two claims point in opposite directions, since one complains of being denied the quotations and the other of having them taken. Even so, the Court held that the counterclaim came within the branch of the equity rule requiring it to be pleaded.6
The Court reached that result by giving the key word a loose, practical meaning. “Transaction,” it said, is a word of flexible meaning that may comprehend a series of many occurrences, depending “not so much upon the immediateness of their connection as upon their logical relationship.”7 The refusal, in the Court's account, sat inside both claims. It was one of the links in the chain of events on which the plaintiff based its cause of action, and an important part of the transaction behind the counterclaim: the “one circumstance without which neither party would have found it necessary to seek relief.”8 Without the refusal the plaintiff would have had no complaint and the exchange no grievance. So close was the connection that the failure of the plaintiff's bill would lay the foundation for the counterclaim, yet dismissing the bill would leave the exchange's relief incomplete unless the court also enjoined the plaintiff from taking by stealth what it could not obtain by judicial compulsion.9
The Court also refused to demand identical facts. It was enough that essential facts alleged by the plaintiff entered into the cause of action stated in the counterclaim, and it did not matter that the counterclaim added allegations of its own, such as the charge that the plaintiff was unlawfully getting the quotations.10 The reason is structural. A plaintiff and a defendant tell different stories about the same dispute, so their pleaded facts rarely, if ever, match in every particular, and a rule requiring a match would rob the compulsory branch of all serviceable meaning.11 The measure of relatedness is therefore whether the claims share a necessary link in the chain of events, which leaves room for each side to plead facts the other does not.
The Second Circuit relied on this reading when it applied Moore under the modern rule. In Crouse-Hinds Co. v. InterNorth, Inc., the complaint challenged a tender offer for Crouse-Hinds stock and the counterclaim attacked an exchange agreement involving Belden stock. The court quoted Moore's flexible-meaning passage, pointed out that Moore treated a refusal to deal and an alleged theft of quotations as one transaction, and held the counterclaim compulsory.12 Later panels have quoted the same language as the working definition in calling a defendant's claims compulsory because they arose out of the transactions forming the subject matter of the case.13 The lesson for an exam answer is that ordinary-language sameness is the wrong yardstick. Two events that a layperson would describe as different, such as a refusal and a theft, can belong to one transaction when each is a link in the same chain.
The question also runs the other way: does every claim between the same parties qualify?
Between the stealth counterclaim and the unpaid-fees claim lies the whole range that the courts' later tests try to sort. The phrase “logical relationship” does not by itself resolve close cases, and efforts to sharpen it by parsing the words of the Rule produce little.14 Moore's definition gives courts wide latitude to decide case by case, which is why the tests in the next subsections matter.15 The same decision is also the seed of what is now supplemental jurisdiction over compulsory counterclaims, a topic a later section develops.16
Same Issues of Law and Fact
Rule 13(a)(1)(A) makes a counterclaim compulsory when it arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, and the text gives no measure of how close that connection must be.18 Courts filled the gap with several tests, and the first asks whether the legal and factual issues raised by the claim and the counterclaim are largely the same.19 The reasoning is straightforward. If both claims depend on the same questions, separate lawsuits would ask two courts to answer one set of questions, which wastes effort and gives two factfinders the chance to resolve them differently. Rule 13(a) addresses that risk by requiring that disputed issues arising from the same operative facts be raised in the same action, a requirement the Federal Circuit has grounded in fairness as well as efficiency.20 A yes answer to the same-issues question therefore points toward a compulsory counterclaim, and many courts treat a yes under any one of the tests as enough.21
Patent litigation shows the test at its cleanest. In Vivid Technologies, Inc. v. American Science & Engineering, Inc. the maker of a security device sued for a declaration that it had not infringed certain patents owned by American Science & Engineering, and the patent owner answered with a counterclaim charging infringement of specified patents, including the two the maker had named.22 The declaratory claim asks whether the accused device falls within the patent's claims, and the infringement counterclaim asks the identical question from the other side, so the legal and factual issues coincide. The Federal Circuit reasoned that a counterclaim for infringement of the same patent readily meets all four tests, and it noted that every court it found addressing the point had treated an infringement counterclaim as compulsory in a declaratory action for non-infringement.23 It also rejected the district court's worry that the counterclaim would add delay and expense, observing that the counterclaim raised no additional issues, that the same patent was the subject of both pleadings, and that the parties bore the same evidentiary burdens whether or not the counterclaim was allowed.24
A highway collision supplies the everyday version of the same pattern. In King v. Blanton, Blanton sued over a collision and King later filed a separate action arising from the same collision; the North Carolina Court of Appeals applied that state's Rule 13(a) to decide whether King's claim was a compulsory counterclaim to Blanton's earlier action.25 The court held that the later claim arose out of the same transaction or occurrence, because the same collision was at the heart of both actions and the only dispute was where the fault lay.26 When fault is the only open question, both claims put one question to the factfinder: who caused the collision? A second trial would hear the same evidence about how the collision happened and could allocate responsibility differently from the first, which is the duplication and inconsistency the compulsory rule exists to prevent.
The same test also sorts claims into the permissive category. In Bose Corp. v. Consumers Union a company sued a consumer organization for unfair competition and Lanham Act violations, and the organization's libel counterclaim turned on the publication and truth of its statements, issues material to neither of the company's claims. Because the issues were largely different, the counterclaim was permissive. Set beside the patent dispute, the hinge is plain: in Vivid a single question about a single patent decided both pleadings, while here the two sides would be tried on different questions that happen to involve the same parties.
Despite those clean results at the extremes, the test has weaknesses that explain why courts moved on to broader standards. If it demands identical issues, it excludes counterclaims that grow out of the very events the plaintiff sued on but raise different legal questions; if it settles for partial overlap, it supplies no measuring rod for how much overlap is enough, and judges must supply a standard the test itself withholds.27 Either defect matters because Rule 13(a) works by forfeiture. A rule that leaves out related claims or cannot be applied predictably is a poor guide to what a defendant must plead, since a wrong guess costs the defendant the claim.
Moore, the decision from which the other tests descend, shows the strict version failing. The issue on the plaintiff's claim was whether the exchange was violating the antitrust laws by refusing ticker service, while the issue on the counterclaim was whether the plaintiff was purloining the exchange's quotations for a “bucket shop” operation, and those issues are largely different.28 Even so, the Supreme Court held the counterclaim compulsory.29 A test that would make Moore wrongly decided cannot serve as the controlling reading of a phrase Moore itself defined, because Moore's reasoning rested on a shared link in the chain of events, and such a link can exist when the legal issues diverge.
A practical difficulty compounds the doctrinal one. Rule 13(a) requires the defendant to decide whether to include a claim at the time the pleading is served, yet the issues in a case take definite shape only after the plaintiff has replied to the counterclaim, if then.30 The same-issues test therefore asks the defendant to compare two sets of issues when one of them does not yet exist in settled form. Predicting how the issues will develop is a shaky basis for deciding whether a claim must be pleaded or lost.
Opinions are not uniform about whether one test controls or the four operate as alternatives. Plant v. Blazer Financial Services, Inc. states that an affirmative answer to any of the four questions indicates a compulsory counterclaim, and Vivid likewise treats each test as one that can render a counterclaim compulsory.31 Even so, the logical-relationship test has commended itself to most courts and now carries the most weight.32 The consequence for an exam answer is lopsided. A claim and counterclaim that share largely the same issues, as in the patent and collision examples, will almost always be compulsory under every test, so a yes carries real weight. A no leaves the question open, because Moore's counterclaim would have failed the same-issues test and was compulsory anyway, and the logical-relationship standard taken up below is the one that decides the close cases.
Same Evidence
Rule 13(a)(1)(A) makes a counterclaim compulsory when it arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, and one of the lower-court tests for applying that phrase looks at proof.34 The same-evidence test asks whether substantially the same evidence will support or refute both the plaintiff's claim and the defendant's counterclaim, and an affirmative answer marks the counterclaim as compulsory.35 The reason follows from what a trial consists of. When the same witnesses, documents, and exhibits will carry both claims, two lawsuits would require the parties to assemble and present that proof twice, and two factfinders hearing it separately could resolve the same facts in different ways. Overlapping evidence is therefore a direct measure of the waste Rule 13(a) exists to prevent, and courts treat it as a reliable signal that the two claims belong in one case.
A long commercial relationship shows the test at its most natural. In JM McCormick Company, Inc. v. International Truck & Engine Corporation the plaintiff McCormick sued for breach of its agreement with International, citing an allegedly unjustified charge-back and a wrongful termination. International's counterclaims alleged, among other things, that McCormick failed to meet certification requirements, install proper communication systems, and provide the quality of product the agreement required, and they included claims about treated plywood.36 International moved to dismiss part of the counterclaims as permissive, arguing that the claims rested on different factual allegations and on separate contracts.37 The court worked within the logical-relationship framework, but its reasoning shows the evidence signal at work. McCormick's claim put the whole contractual relationship in issue, so the product quality International complained of sat inside the plaintiff's own claim. All of the claims arose out of one contractual relationship and were governed by the same body of law, so they would most likely draw on common facts and witnesses, and the court concluded that the counterclaims were most likely compulsory.38 The dispute over whether there were one contract or two could not justify dismissal, because that question was itself contested.
The exam error here is running the logic backward. Shared evidence points toward compulsory status, but a student who notices that the witnesses on the two claims differ and concludes that the counterclaim is permissive has treated a sufficient signal as a necessary condition. Courts have repeatedly held a counterclaim compulsory because it arises from the same events as the plaintiff's claim, even though the evidence needed for each claim is greatly different.39 The simplest example is an insurer's suit to void a policy for fraud, met by the insured's counterclaim for the amount of a covered loss. The proof of fraud and the proof of the loss will have almost nothing in common, yet both claims are halves of one controversy over the same policy: if the fraud is established the insurer owes nothing, and if it is not the insurer owes the loss. There is no sound reason to settle that single dispute in two suits.40 A test that demanded overlapping evidence would exclude exactly this group of cases, which is the standing criticism of the same-evidence test.41
Different proof can also accompany a permissive counterclaim, and the case that shows it explains what separates it from the insurance example. In Jones v. Ford Motor Credit Co. car buyers sued under the Equal Credit Opportunity Act, alleging that Ford Credit's subjective mark-up policy produced higher finance charges for them than for similarly situated white customers. Ford Credit counterclaimed to collect the unpaid contract balances, and the Second Circuit agreed with the district court that those debt-collection counterclaims were permissive.42 The counterclaims concerned the individual buyers' nonpayment after the contract price had been set, and they did not depend on any particular clause or rate. The relationship between the two sets of claims was therefore logical only in the sense that the allegedly discriminatory sale was the but-for cause of the nonpayment, and the essential facts for proving each side were not so closely related that one lawsuit would yield judicial efficiency.43 Whether the mark-up policy discriminated does not answer whether a particular buyer paid, and the reverse is equally true. The insurance claims, by contrast, answer each other. The McCormick claims shared both a relationship and its witnesses, while Jones shared a relationship but not the proof that mattered.
Overlapping evidence thus strengthens the case for a compulsory counterclaim without being required for it, and its absence does not make a counterclaim permissive. What decides the close cases is whether the claims form one controversy that separate trials would split, which is the question the logical-relationship standard asks directly.
The Res Judicata Test
Rule 13(a)(1)(A) makes a counterclaim compulsory when it arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, and one of the tests the lower courts built to apply that phrase borrows from the law of former adjudication.45 The res judicata test asks whether a later suit on the defendant's claim would be barred by res judicata if no compulsory-counterclaim rule existed, and an affirmative answer marks the counterclaim as compulsory.46 Res judicata, also called claim preclusion, is the doctrine that a final judgment on a claim ends the parties' ability to litigate that claim again, along with anything that could have been brought with it. The test attracted courts because both doctrines rest on one idea of repose. When a suit is brought, the court looks back at the incident behind it and expects the related claims to be pleaded together, and the finality of the judgment has to be measured the same way, so that omitting a claim from the same incident forecloses it permanently.47 If that shared logic holds, the thought runs, asking whether res judicata would reach an omitted claim should reveal which claims the Rule covers.
The thought fails for two separate reasons, and the first is circularity. Whether an omitted claim of a defendant is barred is the very question the compulsory-counterclaim rule exists to answer, so the preclusive effect is both the issue to be decided and the test for deciding it.48 Stated in one line, the test says that a claim is compulsory, and will be precluded if not raised, if it would be precluded if not raised, which tells a student nothing about the claim in front of them.49 The test also hands the analysis to another contested field, since the answer now depends on the law of former adjudication, which carries ambiguities of its own.50
The second flaw is that the test's premise is false for defendants. Claim preclusion ordinarily requires that the same claimant be suing the same defendant, and a defendant who later sues the original plaintiff is pressing a claim that runs in the opposite direction, so it is usually a different claim.51 In jurisdictions with no compulsory-counterclaim rule, a pleader typically is not barred by res judicata from suing independently on a claim that could have been a counterclaim in the earlier action.52 The common law tolerated that result because the defendant did not choose the time or place of the first suit, and a defendant haled into the plaintiff's chosen court was not required to counterclaim there even when the claim grew from the same transaction.53 That tolerance invited several lawsuits over one transaction, which is the inefficiency many jurisdictions removed by adopting a rule like Rule 13(a).54
The car-accident example shows the test misclassifying a claim. Pritchard sues Danielle over a car accident, and the court finds that Danielle was not negligent. Danielle then sues Pritchard for her own injuries from the same accident. Danielle was the defendant in the first case and is the claimant in the second, so the claimants differ and traditional claim preclusion does not apply, which means the res judicata test would label her claim permissive.55 Yet Rule 13(a) required her to state the claim as a counterclaim, and because she did not, she cannot bring it in a separate case later.56 Courts describe this result as rule-based preclusion: the bar exists to enforce the compulsory-counterclaim rule, even though the same-claim requirement of res judicata is not met.57 The causal order is therefore the reverse of what the test assumes. The claim is barred because it is compulsory under the Rule, and it is not compulsory because it is barred. The same reasoning protects permissive counterclaims. If res judicata barred them when omitted, the preclusion rules would convert them into compulsory ones and undermine the rulemakers' choice.58
One narrow form of preclusion does exist without any rule, and it is the part of the test that remains sound. Even where no statute or court rule applies, failing to assert an available counterclaim precludes a later action on it if granting relief would nullify the judgment in the first action.59 This common-law compulsory counterclaim grows from the principle that a final judgment bars the defendant from later pressing mere defenses to the plaintiff's claim, because a defendant who could reopen the claim in a new suit would make judgments close to worthless.60 A creditor who sues on an unpaid promissory note and wins holds a judgment that the note is valid and owed. If the debtor then sues the creditor on the theory that the note was the product of fraud, success would contradict that judgment, so the claim is barred, and the debtor had to raise the fraud in the first suit or lose it.61 The goal here is consistency of outcomes, because the creditor should not recover on a note that a second court then declares fraudulent.62
Cadle Co. v. Reiner, Reiner & Bendett, P.C. applies the same principle in a jurisdiction that otherwise treats counterclaims as permissive. After Connecticut courts adjudicated collection and foreclosure actions brought by Reiner, Cadle sued in another forum for breach of the retainer agreement. The Sixth Circuit held the suit barred, because the alleged breach was the very collection action the Connecticut courts had decided, so Cadle in substance sought to undo the amount of those judgments.63 The exception it applied comes from Restatement (Second) of Judgments § 22(2), which precludes a claim that could have been a counterclaim when its successful prosecution would nullify the initial judgment or impair rights established in the initial action.64 Set beside Danielle's suit, the fact that decides the outcome is plain. The debtor's fraud claim and Cadle's contract claim contradict the first judgment, so the common law bars them with no rule at all. Danielle's claim for her own injuries is consistent with a judgment that Pritchard lost, so only Rule 13(a) can bar it.
Courts still acknowledge the kinship between the two doctrines. In Zero Tech, LLC v. Clorox Co., the court framed compulsory status through the logical-relationship standard and noted the Third Circuit's observation that the compulsory-counterclaim inquiry requires essentially the same comparison between claims as the res judicata analysis.65 That kinship explains why the test appealed to courts and also shows that it cannot carry the analysis alone. On an exam, the order of analysis starts with whether the defendant's claim arises out of the plaintiff's transaction or occurrence, and the bar on a later suit is the consequence of an affirmative answer. A defendant's claim that would undo the first judgment is the one exception, since it is barred even in a jurisdiction with no counterclaim rule.
Logical Relationship Standard
Rule 13(a)(1)(A) makes a counterclaim compulsory when it arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, and the test that most courts use to apply that phrase asks whether the counterclaim bears a logical relationship to the opposing claim.67 The standard grows out of Moore's observation that a transaction may comprehend a series of occurrences joined by their logical relationship. An immense body of decisions now treats it as the controlling inquiry under the current Rule, and most of the remaining decisions reach results consistent with it.68 The standard earns that position by asking directly about the Rule's purpose. The same-issues, same-evidence, and res judicata tests each measure one symptom of relatedness, whereas the logical-relationship standard makes the efficiency of trying the counterclaim in the same lawsuit as the main claim the principal consideration.69
In Great Lakes Rubber Corp. v. Herbert Cooper Co. the Third Circuit explained that the phrase takes its meaning from the purpose of the Rule. A counterclaim is logically related to the opposing claim when separate trials would involve a substantial duplication of effort and time by the parties and the courts, as they will where the claims involve many of the same factual issues, the same factual and legal issues, or are offshoots of the same basic controversy between the parties.70 That definition tells a court what to look for, and each part of it has its own reason. Duplication is the efficiency concern: if the same events, witnesses, and documents would be needed in two trials, one lawsuit saves the second and removes the chance that two factfinders will resolve the same facts differently. Fairness is the second concern. A defendant brought into court involuntarily is the litigant most burdened by having to split its grievances across lawsuits, and letting it assert every claim that grows out of the controversy in one proceeding gives it complete relief.71
The facts of Great Lakes show that purpose at work on claims that look different on their face. Great Lakes had sued its competitor Cooper, and the district court dismissed that complaint for want of diversity of citizenship, while Cooper's own counterclaim, which arose under the federal antitrust laws, stayed in the case. Cooper's counterclaim alleged, among other things, a series of baseless lawsuits meant to harass it out of the flexible-hose business, including the very action Great Lakes had filed, and Great Lakes answered with a counterclaim repeating its dismissed allegations.72 Whether that answering claim was compulsory decided whether it could continue, because the same test determines whether a federal court may hear a counterclaim that lacks its own jurisdictional basis.73 The Third Circuit held it compulsory, since Cooper's charge that Great Lakes' lawsuits were baseless and harassing could not be decided without an extensive airing of the facts and the law behind Great Lakes' claims.74 The two sides rested on different legal footings, yet resolving Cooper's claim meant trying the merits of Great Lakes' claims, so a second trial would have repeated the first.
Revere Copper & Brass, Inc. v. Aetna Casualty & Surety Co. gives the standard two concrete senses. A claim is logically related when the same aggregate of operative facts serves as the basis of both claims, or when the core of facts behind the opposing claim activates additional legal rights in the defendant that would otherwise remain dormant.75 The first sense covers the typical case, in which each side tells a different story about one event or one contract. The second sense reaches rights that do not come alive until the plaintiff's claim brings the underlying facts into play, and a right to indemnity is the standard example, because it gives its holder nothing to enforce until some claim threatens liability. Revere itself falls in the first sense. The construction at issue was not finished within the time two contracts allowed, and Fuller, brought in as a third-party defendant, counterclaimed against Revere over that delay. The court treated the two claims as two sides of the same coin, so closely connected that the failure of Revere's claim would supply the foundation for Fuller's.76
The Fifth Circuit uses the same concept but gives particular weight to whether the claim and counterclaim share an aggregate of operative facts. In New York Life Ins. Co. v. Deshotel the court applied that approach to an insurer's interpleader action over life-insurance proceeds and a claimant's later suit against the insurer.77 Both rested on one set of facts: the policyholder bought the policies, named and renamed his beneficiaries, and sent a final change form that reached the insurer but, for reasons not yet determined, was never processed. The claimant had not pleaded a counterclaim in the interpleader, so her later suit over that failure was barred as a compulsory counterclaim she should have raised there.78
Courts apply the standard as a functional judgment and do not run it as a checklist. One formulation, applied in McCormick, directs a court to consider the totality of the claims, including their nature, the legal basis for recovery, the law involved, and the respective factual backgrounds.79 The Second Circuit asks the same question about the essential facts: the claims must be so logically connected that judicial economy and fairness dictate that all the issues be resolved in one lawsuit, though the factual backgrounds need not be absolutely identical.80 Each formulation is a way of asking whether one trial would serve both claims better than two.
Jones v. Ford Motor Credit Co. shows the failing side of that question. Buyers alleged that a subjective mark-up policy raised their finance charges above those of similarly situated white customers, and the lender counterclaimed for their unpaid balances. The Second Circuit held the counterclaims permissive, because the only link was that the allegedly discriminatory sale was the but-for cause of the nonpayment, and the essential facts for proving each side were not so closely related that one lawsuit would yield efficiency.81 Set beside Great Lakes, the difference lies in what each claim required the court to decide. In Great Lakes, resolving Cooper's claim required airing the merits of Great Lakes' claims. In Jones, deciding whether the mark-up policy discriminated says nothing about whether a given buyer paid. A but-for link ties two claims together in time, and the standard asks for more: whether resolving one claim requires or substantially repeats the work of resolving the other.
Flexibility is both the strength and the weakness of the standard. It has been criticized as overly broad in scope and uncertain in application, yet it has by far the widest acceptance among the courts.82 Attempts to divide it into a narrow version and a broad version have gained little traction, since the differences appear to be only the phrases courts use to describe a test that is necessarily flexible.83
The uncertainty falls on the defendant, because Rule 13(a) requires the decision when the answer is served, well before discovery and pretrial motions show what facts, evidence, and law the case will involve.84 A misjudgment forfeits the claim, so a risk-averse defendant has every reason to plead first and evaluate later. That strategy is available because a claim that is not compulsory may still be included in the pleading to dispose of all the claims in one suit.85 The cost of the imprecision is that claims which might never have been asserted get injected into the litigation.86 In an exam answer, the useful question is whether the same event or controversy lies behind both claims and whether a second trial would repeat the first.
Applying the Test
Rule 13(a)(1)(A) asks whether the defendant's claim arises out of the transaction or occurrence that is the subject matter of the opposing party's claim, and the tests surveyed above gain meaning only when a court runs them on facts.88 Decided cases show where the line falls. Courts have held counterclaims compulsory when the two sides share a patent, a contract, an event, or a legal duty, and permissive when the two sides share only a background or when the defendant's grievance comes into being during the lawsuit itself. Three of the decisions below, Harrison, Yaklevich, and Browning Oil, apply state counterparts of Rule 13(a) that carry the same operative language. They illustrate how the federal rule works, but they apply state law and do not bind a federal court applying Rule 13(a).
The cleanest compulsory results come from a shared patent. In Vivid Technologies, a maker of security devices sued for a declaration that it did not infringe certain patents owned by American Science & Engineering, and the owner's counterclaim for infringement of those same patents was compulsory. The Federal Circuit found that every court to address the question had treated an infringement counterclaim in a non-infringement declaratory action the same way.89 The consequence reached beyond forfeiture. The district court had refused to accept the counterclaim for filing, and the Federal Circuit held that the refusal exceeded the court's discretion, because a compulsory pleading on an issue whose merits have not been decided ordinarily should not be turned away on a prediction that it will fail.90 A claim the Rule forces the defendant to plead is therefore a claim the court should accept for filing, with the merits decided afterward.
A shared contractual relationship produces the same answer on less technical facts. In JM McCormick, the plaintiff sought relief for breach of an entire supply relationship, including a charge-back and a termination, and the defendant argued that its counterclaims about the performance of treated plywood were permissive because they rested on different factual allegations and on a second contract.91 The court answered that all of the claims arose out of the contractual relationship and were governed by the same body of law, so they would most likely share facts and witnesses, and that a dispute over whether one contract or two existed could not justify dismissal.92 The opinion also marked the opposite pole by pointing to decisions in which counterclaims were permissive, one where a tort action faced a counterclaim on a healthcare benefit agreement and one where a federal claim about a loan faced a lender's counterclaim on the private loan contract.93 That second pairing returns below, because courts still divide over it.
Transactions that look separate on paper can still be one transaction for this purpose. In Crouse-Hinds Co. v. InterNorth, Inc. the complaint attacked a tender offer for Crouse-Hinds stock and the counterclaim attacked an exchange agreement involving Belden stock. The Second Circuit agreed with the district court that both arose out of the same transaction, and it pointed to Moore, where a refusal to deal and an alleged theft of quotations were held to belong to one compulsory transaction.94 The title of a document or the identity of the securities does not control. What counts is whether the two claims are links in one chain of events.
Single events supply the most familiar compulsory counterclaims, and the standard illustrations show how far the idea reaches. A plaintiff who sues for slander about the sale of oil securities meets the defendants' counterclaim for the price they paid for the allegedly worthless securities, a medical center that sues for unpaid bills meets the patients' malpractice claim arising from the same treatment, and an insurer that sues for a declaration of nonliability meets the insured's claim under the policy.95 In each pairing, the plaintiff's claim and the counterclaim lead into the same dealing. The same illustrations include a near miss. When people injured in the event behind a coverage dispute are joined as codefendants in the insurer's declaratory suit, their counterclaims for injuries are not compulsory, because those claims grow out of the insured's tort liability and not out of the contractual rights between insured and insurer.96 The event is common to all of the claims, but the legal relationship the insurer put in issue is not.
A stakeholder that starts an interpleader action can face compulsory counterclaims too. The Federal Rules apply in interpleader as in any other civil action, so once the stakeholder has joined the claimants, a claimant may counterclaim against it as an opposing party, and the counterclaim is compulsory if it arises from the same transaction or occurrence as the underlying dispute.97 In New York Life Insurance Co. v. Deshotel, the insurer interpleaded the proceeds of a policyholder's life insurance policies. The policyholder's signed form changing the beneficiary had reached the insurer but, for reasons not yet determined and perhaps through the insurer's negligence, was never processed. A claimant's negligence action against the insurer over that failure rested on the same facts as the interpleader, and because the claimant had not pleaded it there, the Fifth Circuit held it barred.98 The claimant's only response was that the claim had not matured when the answer was filed, a limit on the duty that a later section takes up.
Browning Oil Co. v. Luecke shows the contract pattern in a property dispute under the Texas counterpart. Mineral owners sued for breach of the pooling provisions of their leases, and the operator's claim for breach of a letter agreement concerned the same purported horizontal well units. Because both claims concerned at least some of the same facts, the court found a logical relationship between the letter agreement and the leases and treated the operator's claim as arising out of the same transaction or occurrence.99 The operator argued that its claim had not matured until it demanded execution of pooling documents. The court replied that the owners' lawsuit had already signaled their opposition, so with due diligence the operator could have pleaded its claim before the bench trial, and it upheld the order striking the counterclaim.100
A claim between the same two parties can still fall outside the Rule. In Bose, a company sued a consumer organization for unfair competition and Lanham Act violations, and the organization counterclaimed for libel based on the company's complaint, a press release, and an interview given by Dr. Bose. The court held the counterclaims permissive: the publication of the alleged defamation was essential to them but immaterial to the company's claims, a judgment on the company's claims would not bar a later libel suit, and the defamatory language formed no part of the transaction or occurrence the company sued on.101 The press release and interview strengthened the point, since statements made outside the complaint sit even farther from the company's transaction than the complaint's own allegations do.102 The court treated any abuse-of-process claim read into the counterclaims the same way.103 Permissive status does not keep a claim out of the case. In Gouin v. Gouin, a defendant's counterclaim for assault did not arise out of the transaction the plaintiff's claims concerned, and the court allowed it as a permissive counterclaim under Rule 13(b).104 The label decides whether omission forfeits the claim, and the defendant remains free to plead it, subject to the jurisdictional limits a later section takes up.
Claims born of the litigation itself make up a second large group of permissive results. In Harrison v. Springdale Water & Sewer Commission, landowners sued a water and sewer commission for damages, and the commission answered with a condemnation counterclaim that, the landowners alleged, officials admitted at a hearing had been filed only as a tactical measure to pressure them to settle.105 After the chancellor dismissed the condemnation counterclaim, the landowners sued in federal court under the civil-rights statutes, and the city argued that the claim should have been asserted as a compulsory counterclaim in the state proceeding. The Eighth Circuit, applying the Arkansas counterpart to Rule 13(a), saw essentially two different cases and concluded that the claims did not arise out of one transaction or occurrence, because one was born from the other.106 It added that a counterclaim is not compulsory if it cannot be asserted in the same proceeding, and it observed that just compensation is the sole issue in an eminent domain proceeding.107
Abuse of process has the same structure. In Yaklevich v. Kemp, Schaeffer & Rowe Co., the Ohio Supreme Court read Civil Rule 13(A), which uses the same operative words as the federal rule, and held that in a typical case an abuse-of-process claim does not arise out of the transaction or occurrence that is the subject matter of the underlying claim but out of events during the underlying litigation, so it need not be raised there as a compulsory counterclaim.108 The reason is sequence. The transaction the plaintiff sued on is complete when suit begins, and the alleged perversion of the legal process happens afterward. The court acknowledged that some courts treat the claim as compulsory, so that failure to raise it in the underlying case precludes a later suit, and it confirmed that the claim may be raised as a permissive counterclaim in an appropriate case.109 An exam answer should state the common view and note that the decisions are not uniform.
Antitrust claims against a patent owner show courts working out the same question on contested ground. In Mercoid Corp. v. Mid-Continent Investment Co., the Supreme Court held that an antitrust claim asserted against a patent infringement plaintiff was a separate statutory cause of action, permissive under Rule 13(b), so res judicata did not bar it, because the earlier patent litigation involved different matters in issue.110 Some courts read that holding as an exception making antitrust counterclaims permissive in patent suits, while others confine it to its facts and sort antitrust claims by whether they sound in patent misuse, which tends toward permissive, or in patent validity, which tends toward compulsory.111 The district court in Zero Tech, LLC v. Clorox Co. observed that the same sorting could be reached by applying the ordinary logical-relationship test, and it concluded that ZeroWater's antitrust claims were not compulsory counterclaims to the patent owner Brita's pending Delaware action.112
Possible defenses do not enlarge the duty. In the same case Brita pointed to an equitable estoppel defense that ZeroWater had once raised as proof that the patent and antitrust claims were intertwined. The court answered that the evidence for a patent-ambush antitrust claim, which depends on a standard-setting organization's reliance on a patent holder's false representations, differs from the evidence for estoppel, which concerns what the accused infringer itself relied on.113 It added that potential defenses are not relevant to the compulsory counterclaim rule, citing the Federal Circuit's statement in Nasalok Coating Corp. v. Nylok Corp. that the question is the extent of factual overlap and that the mere possibility that affirmative defenses might add issues does not oblige a defendant to assert them as a counterclaim.114 The comparison therefore runs between the claims as the plaintiff has framed them and the claim the defendant holds. Issues that would enter the case only if the defendant chose to raise a defense do not make a related grievance compulsory.
The lender's debt counterclaim in a consumer credit-disclosure suit is the application on which the circuits divide, and a student should describe the split without stating either side as settled. When a borrower sues a lender under the Truth in Lending Act (TILA), the lender typically holds a claim for the unpaid debt on the same loan. The Fourth, Sixth, and Seventh Circuits hold that the debt counterclaim is permissive, and the Fifth and Eleventh Circuits hold that it is compulsory.115 The permissive side reasons that the borrower's suit asks only whether the lender made the disclosures federal law requires, while the lender's claim requires the court to determine contractual rights under state law. It adds that the borrower needs only the loan documents while the lender must verify the obligation and prove default, and that letting the lender use the federal proceeding for private claims would impede expeditious enforcement of the federal penalty.116 The Seventh Circuit put the point more briefly: the only link between the claims is the initial execution of the loan document, and that link is too slight for compulsory adjudication to secure the advantages Rule 13(a) envisions.117
The compulsory side starts from the observation that a single aggregate of operative facts, the loan transaction, gave rise to both claims, so a literal application of the logical-relationship test points toward compulsory status.118 The disagreement therefore comes largely from competing policies: the Rule's goal of avoiding multiple suits clashes with the Act's goal of meaningful disclosure, which creditors' counterclaims may obstruct, and courts also disagree about how far federal courts should be involved in state-law debt claims.119 The label matters because a permissive counterclaim needs its own jurisdictional basis, while a compulsory one falls within ancillary (now supplemental) jurisdiction, so a permissive debt claim with no independent basis would have to be pursued in state court.120 One district court followed the permissive view for the borrower's TILA claim but recognized that the same debt claim might be compulsory as to state-law claims the borrower had pleaded about the sale and repossession.121 Status is therefore measured claim by claim.
Set side by side, the decisions sort along one line. A shared contract (McCormick, Browning Oil), a shared event (the oil-securities slander and the malpractice illustrations), a shared patent (Vivid), or a shared legal duty (the insurer's handling of the beneficiary form in Deshotel) means that resolving the plaintiff's claim requires examining the very thing the defendant complains about, so one trial replaces two and no second factfinder can reach a different result.122 Claims that share only a background, such as the same two parties or the same loan, and claims that arise from the litigation itself, such as the condemnation counterclaim or abuse of process, leave the plaintiff's claim decidable without touching the defendant's grievance, so separate trials would repeat little.
The third step does most of the work, because the patent, contract, event, and duty categories above are shorthand for asking whether one trial would resolve both claims. The fourth step matters because a shared background can be substantial, as when the same loan underlies both a federal disclosure claim and a debt claim, and still fail to make the claims compulsory in the courts that treat the debt as separate from the disclosure question.