AbstractCourts in common law systems decide cases as they decided like cases in the past—even if they believe they decided those past cases wrongly. What, if anything, justifies this practice? I defend two main claims. The first is that fairness favors treating like cases alike if that means treating them correctly. The second is that, in general, a court is as likely to decide an instant case correctly as it was to decide a previous and like case correctly. Together, these claims tell us that departing from and following precedent are equally likely to yield a correct decision, whereas following precedent may also yield a fair decision. Adhering to precedent is the dominant alternative, as a result. Fairness therefore justifies the practice of precedent. While this conclusion is not original, my argument for it is.