Hello readers! We’re bringing you another edition of Boom! Lawyered, wherein my colleague Jess Pieklo and I explain legal concepts to you while congratulating you for not going to law school. It’s the most wonderful time of the year, besides Christmas—if you’re into that sort of thing.

But I digress.

This time, we’re going to explain what res judicata means, recently invoked during the oral arguments for Whole Woman’s Health v. Hellerstedt.

First, let’s revisit our sex tape hypothetical. During our SCOTUS edition of Boom! Lawyered, you and your ex-husband were battling it out in the Supreme Court over whether or not your ex had the right to publish nude photos of the two of you to his website. After you found the photos on his website, you sued him in federal court, lost, appealed to the Ninth Circuit Court of Appeals, lost again, and then pleaded your case before the Supreme Court.

And for the sake of argument, let’s say that you lost again: The Court rules that your ex was well within his First Amendment right to publish the photos on his website.

Your case is over. Dead. Six feet under. Taking a permanent dirt nap. Because of res judicata in action.

So what is res judicata, you ask? Aside from being one of the most frequently preferred Latin phrases of first-year law students—right alongside such gems as “ipse dixit” and “in flagrante delicto“—res judicata, also known as “claim preclusion,” is a legal doctrine that prevents a plaintiff who loses a lawsuit from gaming the system by filing successive lawsuits against the same defendants, seeking damages to rectify the same injury.

That was plain English. Now I’m going to hit you with the legal definition. Try not to panic.

The doctrine of res judicata says that a final judgment on the merits rendered by a court of competent jurisdiction is conclusive as to the rights of the parties and anyone in privity with them, and acts as an absolute bar to a subsequent action involving the same claim, demand, or cause of action.

Your eyes started to glaze over. I know it. So let me break that down for you before you slam your laptop lid down in frustration, or poke angrily at that little X on the open tab in your iPad Internet browser.

What does “a judgment on the merits” mean?

That means either a judge or a jury examined the facts and the law and decided whether the plaintiff or defendant should win, and why. (In some cases, judgments are entered without even examining the facts of the case. When a defendant refuses to respond to the lawsuit or show up in court to defend themselves, the plaintiff can get what’s called a default judgment entered against the defendant. That means that even though the defendant never made his case in court, the plaintiff shouldn’t have to wait around forever until the defendant decides to show up.)

A judgment on the merits excludes, for example, situations where a case is dismissed on a technicality: for lack of standing (meaning the court ruled that the plaintiff isn’t the proper person to be bringing a particular lawsuit because she has no connection to the injury being alleged), because the case is premature, or something else of that nature. That kind of dismissal is a “dismissal without prejudice,” which means the plaintiff can re-file their lawsuit once they fix the technical deficiencies. A dismissal with prejudice means that the case cannot be refiled and all claims that were brought or could have been brought in that case cannot be brought again.

What does “a final judgment on the merits rendered by a court of competent jurisdiction” mean?

It means that a court that had jurisdiction over the case (in other words, legally could hear and decide the case) made a final decision in the case and entered judgment. So if you’re trying to make claims about violating a state law in Kansas, an Iowa court isn’t the place to be, with some exceptions not worth getting into here.

What does “privity” mean?

“Privity” is a legal term that describes the connection or mutual interest between two parties—that connection could be a contractual relationship, a blood relationship, or any interest where one party’s legal interest lines up with another’s. So if Bruce Wayne sues Tony Stark for patent infringement and loses—let’s say Bruce Wayne alleges that Tony Stark based the Iron Man suit on patents he stole from Wayne Enterprises—Batman, who is legally related to Bruce Wayne, could not turn around and sue Tony Stark for patent infringement based on those same patents. Nor could Wayne Enterprises. Both Batman and Wayne Enterprises are in privity with Bruce Wayne, and Bruce Wayne already sued over the Iron Man suit patent and lost. Basically, you can’t lose a lawsuit and then have someone who is legally related to you in some way sue in your stead.

It is important to remember that res judicata not only applies to claims that were actually brought and litigated, but also to claims that could have been brought and litigated.

That means if you’re planning on suing based on a set of events, you need to make sure you include in your lawsuit every possible claim based on that same set of events; the law will not permit you to file multiple lawsuits making myriad claims about the same set of events. You have to put all your eggs in one basket, and then file that basket in court, so to speak.

In legal terminology, the set of events that forms the basis of a lawsuit is called “a nucleus of operative facts.”

If a court enters judgment against you, all claims that you made and all claims that you could have made have been decided against you. (However, if other facts arise that you didn’t know about at the time of your original lawsuit, you can file a new one.)

Going back to our sex tape example, after you’ve lost your claims that your ex-husband violated your state’s revenge porn statute, the doctrine of res judicata means the law won’t let you sue him for intentional infliction of emotional distress, and then a year later sue him for violation of copyright law, and then a year later sue him for invasion of privacy. You have to file all your claims about the situation in one lawsuit.

Here’s another example, in case you’re getting tired of the sex tape hypothetical. (Although, I bet you’re not tired of watching this, amirite?!)

Let’s say you get fired from your job because you refuse your boss’ sexual advances.

You sue your former employer in state court for wrongful termination, claiming that your termination was retaliation for fending off your boss’ sexual harassment. Your employer is able to come up with performance-based reasons for your firing, and you have no proof that your boss sexually harassed you aside from your word—and we all know how that tends to go. You lose the lawsuit. The court enters final judgment on the merits in favor of your employer.

After you lose, it occurs to you that your former employer’s behavior might violate federal law—Title VII of the Civil Rights Act of 1964, to be precise. So you hire another attorney and file another lawsuit, this time in federal court, claiming that your former employer violated your civil rights.

Once your employer gets wind of the lawsuit, they will ask the court to dismiss the case, raising res judicata as a defense. Your civil rights claim arises out of the same nucleus of operative facts, they’ll argue, and the court will most likely agree. Nothing about the situation that led to the lawsuit has changed: No new facts have come to light, and your allegations are the same as before. You’re just seeking a different remedy. You should have combined your state claims and your federal claims into one lawsuit.

And this rule makes sense, right? The courts are already so clogged that it can take years to litigate the simplest cases. Some commercial litigation—when one company sues another company for money—can take a decade or more. Now imagine if a plaintiff could file a lawsuit based on a set facts and then, when she lost that lawsuit, could bring another claim based on the same set of facts because she wanted to increase her chances of winning.

It would be chaos. Madness. And we can’t have that, now can we?

So there you have it. A quick and dirty lesson on res judicata.

Now if you’ll indulge me for just a while longer, I’d like to give you an example of how you can apply your new res judicata knowledge to one of the most talked-about cases this year.

During oral arguments in Whole Woman’s Health v. Hellerstedt last week, Justice Ginsburg kicked off the proceedings by asking whether or not Whole Woman’s Health’s claims were barred by res judicata. An interesting discussion of res judicata ensued, with Justices Kennedy, Alito, and Roberts all chiming in. And because there’s a slight—infinitesimal, really—chance that the Supreme Court could latch on to res judicata as a way to avoid ruling on the merits of the biggest abortion case in decades, I will break down the argument into plain English.

First, I have to introduce two new concepts when talking about challenging statutes as unconstitutional: the “as-applied” challenge and the “facial” challenge.

A facial challenge to a statute argues that the statute is unconstitutional on its face, meaning, essentially, there’s no world in which the law is constitutional. An “as-applied” challenge argues that the statute is being applied in a particular situation in a manner that is unconstitutional.

Now, on to the explanation of how this relates to the Supreme Court oral argument.

Whole Woman’s Health is one of the clinics that sued the State of Texas claiming that the admitting privileges provision of the nightmarish law HB 2 was unconstitutional on its face. That case was called Planned Parenthood v. Abbott. In that case, the district court facially invalidated the admitting privileges requirement, meaning the court ruled that it was unconstitutional on its face. The ultra-conservative Fifth Circuit Court of Appeals disagreed and rejected the argument that the admitting privileges law was unconstitutional on its face.

Days after the Fifth Circuit’s decision, Whole Woman’s Health filed a new lawsuit challenging the admitting privileges requirement “as applied” to two specific clinics. Whole Woman’s Health also facially challenged as an undue burden the provision of HB 2 requiring abortion clinics to conform to ambulatory surgical center (ASC) standards.

Texas argued that the lawsuit should be thrown out on res judicata grounds. Since Whole Woman’s Health had previously challenged HB 2 in Abbott, it said, the ASC regulations claims—that they place a substantial obstacle in the place of a woman seeking abortion—should have been raised in that lawsuit. Both the admitting privileges claims and the ASC regulation claims arise from the same set of events: the passage of HB 2. Remember, res judicata bars not only claims that you brought, but claims that you could have brought.

Whole Woman’s Health responded that res judicata did not bar its “as-applied” admitting privileges claim, because although it had lost its facial challenge, newly developed evidence regarding, in particular, the difficulty that doctors from two specific clinics were encountering in getting admitting privileges at a local hospital were grounds for a new lawsuit.

As for the ASC requirements, Whole Woman’s Health argued that even though the ASC requirement was stated in HB 2, the implementing regulations did not come until much later. In other words, the Texas Department of State Health Services had not yet figured out what changes abortion clinics would have to make in order to comply with the new law, which means Whole Woman’s Health did not know until after it filed its first lawsuit (Abbott) that the ASC regulations were burdensome. The claims in Whole Woman’s Health v. Hellerstedt regarding the ASC regulations lawsuit, therefore, would have been premature at the time Abbott was filed. (In legalese, premature claims are called claims that are “not ripe.”)

Take a spin through the first 15 pages of the oral arguments transcript, if you want to read the justices’ musings on res judicata.

Ultimately, it is unlikely the Court will punt on a technicality. If the Court thought the claims made in the case were barred by res judicata, it likely would not have granted certiorari in the first place.

That’s all for now! We’ll see you again in a couple of weeks.