Most civil lawsuits involve two basic components: proving liability (somebody did something wrong) and proving damages (money paid to compensate for the wrong). Normally, judges and juries cannot put the Genie back in the bottle and undo the alleged misconduct; they can only decide a dollar award to serve as a remedy. And just as they can’t undo a past wrong, judges won’t typically step in to prevent feared future conduct. As a general rule, the judicial system limits its jurisdiction to a “case or controversy” where an alleged injury has already occurred.

Judges do, however, retain certain “equitable” powers – powers that seek to avoid an injustice that may otherwise result if strict procedural rules are applied. Most dramatic, perhaps, is the power to issue an “injunction.” An injunction is a court order to do, or to stop doing, a certain thing. And a preliminary injunction is an injunction issued even before the Court has conducted a trial on the dispute at hand. Imagine that a historic landmark faces demolition where a question over ownership exists. Or imagine that Coca-Cola’s senior product designer quits amid suspicion that she kept a copy of the secret formula. What does the aggrieved party do? Quickly file a lawsuit and ask for an injunction.

While judges retain broad equitable powers, they can’t hand out preliminary injunctions like candy in a 4th of July parade. They need to ask two key questions: Does it appear probable that the complaining party will prove its case at trial? If so, will the harm suffered between now and then be so great that no meaningful remedy will remain after that trial? In other words, will the harm be “irreparable?” Balancing the answer to these two questions, a judge decides whether to issue an injunction, which is normally considered an extreme form of relief. Using the historic landmark example, if the judge is not convinced that the complaining party has a meaningful chance of proving ownership, she is unlikely to hold up the demolition plans of the rightful owner. In the Coke case, on the other hand, she might decide that the devastating commercial impact that could follow a leak of the secret formula outweighs any hardship to the departing employee and justifies injunctive relief.

Often, judges issue injunctions only long enough to allow time for a more in depth review or for the trial itself. Once issued, injunctions can be enforced by the Court’s contempt powers. A party dissatisfied with the Court’s ruling, whether granting or denying injunctive relief, may seek immediate appellate review, but such review is granted in only the most extraordinary cases.