The Power of Unwritten Rules

When talking about the DM and the game world, terms like consistency and inconsistency come up again and again. But what do they actually mean? And why does it matter at all?

To get closer to the meaning, you first have to understand that alongside the official written rules of the Player's Handbook, the Dungeon Master's Guide, and the many other books, there are far more rules at the table. These, however, are never written down. We're talking about the rules that the DM establishes through the game world itself.

When players are guided through the world by the DM, go on adventures, defeat evil, and level up, you might think the rules from the books play the biggest role. In my opinion, the opposite is true. In the fewest possible moments do people actually reference the rules from the books. Much more often, players make decisions based on their understanding of how the game world works and what freedoms it grants them. Even the consequences of their actions are defined - and legitimized - by this unwritten set of rules.

Deadly Ice Storms

Say, for example, a DM establishes in a homebrew world the reality that the region is plagued by deadly ice storms that occur every night - that's nowhere in any rulebook. Yet it will fundamentally shape the players' experience and decisions.

They will most likely do everything they can to be protected from the storms at night. The DM will give them information about what options exist for that. The players may also want to learn the origin of these storms and see how it affects the world's inhabitants.

Let's follow this example. After just a few minutes of play, the following unwritten set of rules might emerge:

• After sunset until sunrise, a deadly ice storm rages, turning every creature into an ice statue within seconds.
• The ice storms cannot be stopped by anyone.
• A rumor circulates that an ancient ice dragon deep within the world is causing the storms.
• Players are only safe from the storms in underground caves.
• Countless cults and sects exist, trying to unite the world's inhabitants through sacrifice and other magic and offer them protection.
• The greatest treasure in the world is a crystal water that can thaw the storm's victims and bring them back to life.

I can't stress this enough: these rules largely determine the players' experience. Because the experience consists of interactions with the game world, and those interactions are governed by the rules the game world establishes. The game world, in turn, is created by the DM - who therefore holds control over these unwritten rules.

The fact that players can't look these rules up shows just how much responsibility rests on the DM to make sure these rules are upheld - reliable, consistent, and comprehensible - in other words, consistent.

Using Inconsistency as a Tool

There's good news. First, it's relatively easy to keep your own game world consistent. Second, a DM can easily turn accidental inconsistency into exciting plot twists, puzzles, adventures, and mysteries.

Let's first look at the two ways a game world can become inconsistent:

• Existing rules are sporadically suspended. Example: Suddenly it seems more or less random whether creatures turn into ice statues, or all at once the underground caves no longer stop the ice storms after all.

• New rules are introduced that make the old ones obsolete, ineffective, or irrelevant. Example: A faction that possesses vast amounts of crystal water gives it away to the population and thereby banishes the threat of the ice storms. The players find a spell that lets them pass freely through the ice storms.

What matters is that, in most cases, when players first encounter an actual inconsistency, they don't strip the entire game world of its legitimacy - instead, they treat the inconsistency as an exception, as an anomaly. In most cases they want to get to the bottom of these anomalies. This once again shows just how strongly these unwritten rules shape the play experience. They see the anomaly as part of the game world - as a kind of puzzle to be solved.

What's notable here is that an anomaly places a silent obligation on the DM to make sure a coherent, comprehensible solution exists. If it doesn't exist, or if players get the feeling that this anomaly isn't actually part of the game world, the mask slips and it's revealed as an inconsistency.

From that point on, players start doubting the world, the DM's ability to control the unwritten rules, and worse still - they start doubting every past event of the adventure, whether success or failure. I don't need to stress that this is one of the most unfortunate situations a DM can find themselves in.

That's why it's tremendously important to have an explanation ready for accidental inconsistencies, so players can solve the puzzle. Only with a comprehensible solution does consistency remain intact.

The Dose Makes the Poison

The fact that inconsistencies can be used as a story element is no coincidence or quirk unique to tabletop RPGs. Plot twists work exactly the same way.

Truths or rules established across multiple situations undergo a sudden turn that wasn't predictable. Let's consider for a moment what a movie would do to us if it had a plot twist every five minutes, constantly overturning truths that had just been established. That hypothetical movie and its world would feel full of coincidences, arbitrariness, and without any control whatsoever - inconsistent. Before long, you can no longer take the twists and developments seriously.

That's exactly why disguising inconsistencies as anomalies (plot twists) should be used with care. It's easy for overuse to build a house of cards of obligations toward the players that can never be resolved and eventually collapses in a storm of questions and frustration. It's tremendously important to leave enough rules standing to give players a healthy amount of control over the game world, and to make sure plot twists remain an exception and continue to surprise the players.

That's why you should avoid piling new rules onto the existing ones at a rapid pace. Otherwise, in a very short time, such a large body of rules would emerge that neither players nor the DM could keep track of it. Such a world feels uncontrollable, unpredictable, and simply overcomplicated - just like a movie that "surprises" its audience with a plot twist every five minutes.

Conclusion

The play experience is largely shaped by unwritten rules of the game. A DM is the master of these unwritten rules. To manage that well, you need to organize yourself, understand which rules players pay particular attention to, and, where appropriate, deliberately break rules to create exciting puzzles and plot twists.

At every point in time, players need to feel that both they themselves and the DM have control over the world. Because inconsistency can only exist within a consistent game world.