Last October, I wrote an article discussing some of the spells in Dungeons and Dragons would fundamentally rework the economics and structure of society. One commenter, however, pointed out a spell that I hadn’t thought to discuss. This article is intended to fill that gap.

The enchantment in question is the 2nd level spell Zone of Truth. Basically, anyone in the fifteen-foot Zone of Truth for the ten minute duration of the spell cannot knowingly tell a lie. They can attempt to resist the effect of the spell, but only for a short period of time, and the caster is aware if a person is not yet under the effect of the enchantment. The spell means that it is possible to determine truth from lies, with huge implications for law, negotiation, and everyday life.

First, we must discuss the logistical limitations of the spell. In most worlds, magic users are a rare sight, and in Dungeons and Dragons, casters can only cast 2nd level spells a certain number of times per day, probably 2-4. In a previous post, I estimated that no more than about 0.16% of the population of a typical fantasy realm would be able to cast spells of 2nd level or higher. That means that in a large city of 100,000 people, perhaps 160 people would be able to cast Zone of Truth. Each ten minute casting, in turn, might be used to establish truth in 3-4 cases, if you really hurried. That means that, at an absolute max, Zone of Truth could be used for about 1920 cases per day. That would be enough to get absolute truth on even the most trivial case.

In reality though, casters might want to use their spell slots for other purposes. Why cast Zone of Truth when you could use the same 2nd level slot on Lesser Restoration and cure someone permanently of cancer? And what about days off? You can’t expect everyone to work without weekends or vacation. What this means is that despite the theoretical maximum of 1920 cases tried truthfully per day, a city could probably only handle a tiny percentage of that, say a few hundred, which would likely be enough to handle many, but not all, of the cases that require truthtelling.

A New (Old) Legal System

Zone of Truth would change the way people think about law and trials. If you can determine whether is statement is true or not through a quick spell, trials would be short and simple. An accused person would be asked whether they committed or aided a crime, and if they responded in the negative, they would be automatically cleared. If they said yes, or failed to respond, they might then be asked if they had any mitigating circumstances. Whether or not they did, their guilt would be incontestable.

If given the tools to see truth, and therefore unambiguous guilt, people would begin to see law in black and white, as a clear split the innocent and the guilty. That’s very different from the way most countries today see crime. The works of Agatha Christie, the best-selling novelist of all time, constantly return to the question of ambiguity in law and guilt. In her books, we often see criminals commit crimes for good reasons, or people being technically innocent of a crime yet morally complicit. When we as a society view guilt as something that is indefinite and subjective, we gain a more merciful and generous legal system. We delve deep into a defendant’s life to look for mitigating factors, and often dismiss minor infractions like jaywalking because we assume that many people have also committed the crime but gotten away with it. A system built around hard truth and lies, like a fantasy realm with access to Zone of Truth, would be less likely to see these grey areas.

Interestingly, medieval justice was originally very similar to the Zone of Truth world we are describing. For much of the early Middle Ages, many part of Europe used “trial by ordeal” as a method of determining guilt. A person might, for example, be thrown into a pool of water at the behest of a Catholic minister. If the person sank, they had been accepted by God and were innocent. If they floated, they were guilty. Trial by ordeal created the kind of unambiguous judgement that Zone of Truth might, and may have been responsible for immediate and harsh justice system of the Middle Ages. Yet by the later medieval period, things began to change. Lords and kings began to take power away from the church, and secular courts began to conduct trials in a way not too dissimilar from the modern justice system. This transformation created the system of grey areas and ambiguity that we today take for granted.

In recent years, however, the United States has brought back certain qualities of the medieval legal system. The American justice system draws much sharper distinctions between criminals and non-criminals than most other systems. Lengthy backlogs and large numbers of prisoners have encouraged courtrooms to handle cases quickly, boiling down complex legal matters into a simple “innocent” or “guilty.” American prisoners have less access to the outside world, suffer worse treatment in prisons, and in many states, lose the right to vote.

Of course, fantasy realms would be unlikely to imitate the mass incarceration of today’s United States. Most fantasy realms are (at least vaguely) medieval, and lengthy jail sentences were extremely rare in pre-modern societies. It was simply too expensive to permanently house, guard, and feed a large population of criminals. Instead, criminals would face fines, public humiliation, corporal punishment like whippings, exile, or even execution, depending on the severity of the crime. Punishment was quick, severe, and often left permanent consequences. When given the ability to determine guilt unambiguously through Zone of Truth, punishments would become even more instantaneous and brutal.

In today’s world, a prisoner can plead guilty to their crimes, and in doing so, typically receive a lighter sentence. In a Zone of Truth world, however, prisoners would have no such option, since most cases could be handled with Zone of Truth. As a result, there would probably be no legal distinction between those who confessed and apologized for their crimes and unrepentant deniers. Zone of Truth has a hard time determining emotions and remorse, so the legal system would probably focus on simple punishment.

Zone of Truth, however, would not just have applications for the justice system. A running theme in my previous articles about D&D magic is the fact that magic tends to grant greater power to governments and big organizations, which can in turn use to control the wider population. Zone of Truth is no different. I can imagine countries forcing anyone crossing into their borders to submit to questioning. Medieval societies tended to have very blurred and permeable borders, but if governments had the ability to question newcomers with certainty of truth, there might be more reason to enforce borders. During times of war or paranoia, Zone of Truth users would be pushed to the limit of endurance, with countless people suspected of malicious intentions.

The net result of Zone of Truth would be a society that was both more trusting of a particular in-group, whose motives have been verified by Zone of Truth, and less trusting of everyone else. Given the availability of Zone of Truth, people might be very uncomfortable at the idea of taking someone at their word, or even of oaths themselves when not verified by magic. People capable of casting Zone of Truth would be highly sought after, particularly as their skills became increasingly essential for anytime two people wanted to collaborate on an important undertaking. We might expect to see a lot fewer people being cured of cancer or serious illnesses, as casters instead used their 2nd level slots to verify business contracts or wedding oaths. Society would become so paranoid of deceit that it might become completely dependent upon these casters.

Foul Play

There is another wrinkle to the system: the caster can deceive. If a person successfully resists Zone of Truth, only the caster is aware, so they could easily tell viewers that a witness is being truthful when in reality they are spouting lies. This ability to influence the result of hearings is immensely powerful, because the effects of the Zone of Truth spell would probably be trusted implicitly.

Obviously, governments would take some sort of measures to prevent that, such as requiring casters to take oaths of honesty. But the only way to prove that a caster had lied would get confirmation from another person casting Zone of Truth, and what if the second person is lying? Quis custodiet ipsos custodes?

Similarly, there are a few other ways for people to get around Zone of Truth. The spell only prevents a person from telling a deliberate lie, so an ignorant person would be essentially immune to the spell. You might see crime lords or political schemers relying heavily to catspaws and uninformed minions to commit crimes or execute schemes. Particularly crafty leaders might even brainwash young children to believe things that would circumvent Zone of Truth, such as the belief that they have no agency, and that some other power is acting through them. If such a person was asked, “did you kill Lord Larkin?” they could honestly answer in the negative, even if they had sliced the lord’s throat open just five minutes earlier.

Of course, anyone who sought to abuse the trust society placed in the Zone of Truth spell would act with caution. If perversions of the spell became so commonplace as to be a serious problem, people would cease to trust the spell implicitly, and all the effort spent circumventing it would be wasted. But if they acted subtlety and sparingly, an individual could gain a lot of power and influence by using Zone of Truth as a shield.

Any society with Zone of Truth could, in theory, be much more just than the one we have today. Knowledge of deceit, however, can also lead to a paranoid and unforgiving society. All in all, I prefer it when we give everyone the benefit of the doubt.