Law is not only about hard cases. There are easy ones as well, and understanding law requires awareness not only of litigated and then appealed disputes, but also the routine application of legal rules and doctrine.1 Upon leaving the courthouse and its domain of difficult controversies, we observe the everyday determinacy of law-the production of clear guidance and uncontested outcomes by straightforward legal language, black-letter law, and the conventional devices of legal reasoning.
One consequence of the existence of easy cases along with hard ones is the alleged marginalization of the skeptical challenges of Legal Realism. Legal Realism is conventionally understood, in part, to question legal doctrine's determinacy and positive law's causal effect on judicial decisions.2 But if Realism's skepticism about the constraints of positive law applies only to the sliver of legal events that are litigated cases,3 Legal Realism's challenges can be kept at bay. Realism may remain a valuable corrective to the view that even most appellate cases have a legally right answer, but not as a claim that undermines the routine determinacy of law.4
This marginalization of Legal Realism-its taming, so to speak-turns out, however, to ignore a central Realist theme: the distinction, in Karl Llewellyn's words, between "paper rules," on the one hand, and "real rules," or "working rules," on the other.5 For Llewellyn and other Realists, the crux of their challenge to the traditional view of legal determinacy lay in the fact that the paper rules-the language of statutes and black-letter common law rules-were often poor approximations of the actual rules motivating judicial decisions.6 Judges do follow rules, Llewellyn and most other Realists insisted, but the rules they follow are often not the ones found in standard legal sources.7
The distinction between real and paper rules is well known, but the effect of the distinction upon the supposed marginalization of Legal Realism has remained unnoticed. For when the paper rules do not describe the actual rules that judges use in making decisions, the divergence between paper and real rules will influence the distribution between easy and hard cases. Thus, even if the indeterminacy claims of Realism are limited to the domain of litigated cases, the distinction between paper and real rules determines the makeup of that domain, and accordingly pervades the entirety of law. The gap between paper and real rules, therefore, by producing consequences throughout law and not merely to a small subset of it, reveals the Realist challenge to be more foundational, less marginal, and-importantly-less tamed.
The question I address is as fundamental as it is simple: What makes hard cases hard, and easy ones easy? The answer is empirical, varying with time, place, and area of law. But Legal Realism in its untamed version not only directs us to this question, but also suggests that the answer to the empirical question might, in some contexts and in some domains, challenge the standard view of how law works even in its routine and nonlitigated operation.
I. Legal Realism-Some Basics
The perspective variously known as legal realism, Legal Realism,8 or American Legal Realism9 is widely understood to pose a substantial challenge to a traditional conception of law and legal (especially judicial) decision making. Of course there are almost as many traditional views about legal decision making as there are viewers, but a prominent one holds that official legal materials such as statutes and reported court cases can generate straightforward, mechanical, or logically entailed10 applications in the vast majority of instances.11 And even if the production of legal outcomes is not strictly a matter of syllogistic deduction, a softer version of the traditional view holds that legal outcomes are still the constrained product of legal doctrine and legal materials alone.12 This is roughly the position embodied in the writings of William Blackstone,13 Edward Coke,14 and other celebrants of common law reasoning. …