Introduction
Hey there!
One of the most strange lessons in worldbuilding is that adding limitations does not hinder your creativity. Restrictions fuel ideas. If you throw a lot of random ideas at a page and build your world in that manner, you’re going to end up with a world that strains credulity. It can be difficult to connect all of these things later in a way that makes narrative sense in a story, or provides a believable world for TTRPG players. I’ve done this! My previous campaign setting was developed over years and years of adding one in-the-moment idea to another, and while it was a well-loved world, it also sometimes had some pretty bad inconsistencies or logical fallacies shining through the fabric of our stories.
This post explores how such constraints can drive better worldbuilding. I’m using my new setting, Maelstrom, as a case study as we go.
The Paradox of Choice
You’ve probably heard of it before. The paradox of choice, or “overchoice” is an axiom that essentially translates to “if you have too many choices that can make it harder to choose.”
If you sit down to build out the details of your world and your starting point is “anything is possible,” you might think that would make things easier. It’s a clean slate, an open canvas, ready for your creativity to shine through. But when anything and everything is on the table, you face decision paralysis at every turn. This happens in many instances in life. Recall the last time someone said to you “I’d eat anything” when you also didn’t have a strong preference. Or when a teacher in school suggested “anything” as a report subject. If you don’t already have very strong ideas, this can present an overchoice situation.
Should your world have two moons or three? Does it matter? Should magic come from gods, from the land, from people’s blood? Should there be dragons? The answer to all of these questions is “sure, whatever I want, right?”. But that’s a problem, eventually, because without something to push back against, you end up either frozen by all of the options. Or, you just run with whatever sounds cool in the moment, and there’s no cohesiveness to the world you’re constructing.
The result ends up being a world that just resembles a series of tropes more than it does any original place. Magic solves every problem, so nothing feels tense. Geography is somewhat arbitrary. Cultures exist to fill fantasy archetypes rather than because they emerged from the conditions of the world they live in. The world doesn’t feel real, because nothing in it is connected to anything else by logic or necessity.
Constraints are a way to temper this, and make the things you do include matter more.
Types of Constraints
Not all constraints are created equal, and most good settings have several types working together.
Physical Constraints
These are the natural laws of your world. The rules of physics and science are the things that create cascading effects across everything else. This kind of constraint can be the bedrock of your world. Immutable facts that can’t be changed just by the will of the people who live there. They can’t change the laws of physics, and if they don’t have literal magic, they probably can’t avoid them, either, so they have to adapt.
Maelstrom’s core physical constraint is an idea called tidal locking. The planet’s rotation is perfectly synced up to its orbit, such that it doesn’t appear to turn relative to the star. One hemisphere of the world is always in sunlight, and the other faces perpetual darkness. That single mechanic and its two natural constraints (a region of constant darkness and a region of constant light) generates an enormous amount of little worldbuilding nuggets that I can mine with low effort:
- An eternal storm rages at the substellar point (the spot directly under the star), driven by the temperature differential between hemispheres (and kept stable by complex magic!).
- Wind patterns are dominated by the Storm, creating weather patterns across the entire planet.
- The plant life on Maelstrom has evolved with the sunlight of a red dwarf star. Plants trend toward dark coloration to absorb as much of the available spectrum of light as possible.
- There is no day/night cycle. That means there is no navigation through “the sun rises in the east” type concepts. In fact, there is no concept of “morning” or “evening” or even “day” and “night” as time markers. This creates an entirely different relationship with time itself.
None of these details required me to sit down and brainstorm “what would be cool.” They emerged from following the implications of one constraint (which was, itself, the “cool” thing).
Cultural Constraints
Social rules or patterns, such as taboos and traditions, can all constrain how people in your world behave. Maybe just as importantly, those things can also dictate why they behave the way they do.
In Maelstrom, the only permanent human settlement is a city-state called Landfall. It exists in territory dominated by fey courts. Humans only arrived on this world a few centuries ago, so they are, as a species, aliens here. That single political reality constrains everything about how Landfall operates. Foreign diplomacy is cautious, human expansion is limited, and Landfall’s citizens live with a background awareness that they exist at the sufferance of powers far older, stronger, and stranger than they are.
Cultural constraints are especially useful because they create tension. Characters who push against cultural limits are inherently interesting, and conflicts between cultures with different constraints write themselves.
Magical Constraints
Magic is where a lot of worldbuilders go wrong. Magic without rules is just a cheat code for writing and worldbuilding. It removes problems for the writer at the expense of creating problems for your world’s inhabitants. And they need problems to be interesting! The more clearly you explain and codify what magic can’t do, what magic can do, and what it costs to do it, the more interesting it becomes. Sanderson’s First Law discusses this in great detail.
What are the limits of your magic system? Who can use magic and who can’t? What’s the cost of doing the magic? Do you pay in blood, or in some ethereal mana? Do you pray to some deity or unlock hidden power in the world around you? If you can just throw around fireballs at will, in your world, that could be crazy, but it could also be a bit dull conceptually. If though, to use fire magic, you have to burn something first, or someone, all of a sudden we have a story, or stories. The constraint immediately creates conflicts that we can exploit.
Technological Constraints
What do the inhabitants of your world have access to, as far as technology goes? Available materials, accumulated knowledge, and the physical conditions of the world all shape what technology looks like.
Here’s a small example from Maelstrom that I love. We’ve established that there’s no day/night cycle, and thus there’s no intuitive way to track time other than perhaps moon cycles, which can be less than obvious for observers in some areas of the light hemisphere. The human inhabitants who arrived here needed mechanical timepieces in order to keep track of collective time. They built clock towers all over the city that are kept in sync. This allows for a city-wide system of “watches”, where people do essentially a shift of work, a shift of living, and a shift of sleep, since there are no sun cues to naturally provide boundaries.
There are portable winding watches for traveling teams of merchants or diplomats or explorers. The need for clock towers and watches immediately raises further questions:
- Who builds and maintains these devices?
- Who controls the “official” time, or standard of time?
- What happens when clocks disagree?
A simple waterfall effect from a tidally locked planet to the fact that the human city has no sunrise has now created a technology (clockwork timekeeping) that became a source of political power and social structure. And raises the specter of other clockwork type technologies, as well.
How Constraints Generate Content
Problem, Solution, New Problem
This is the very engine that makes constraint-based worldbuilding so productive. Each constraint creates problems for the people living in your world. Their solutions to those problems become worldbuilding details. And those details, inevitably, create new problems that demand further solutions.
Take the previous timekeeping example and follow the chain:
- Constraint: The planet is landlocked and has no day/night cycle.
- Problem: How do people track time, then, in a way that makes sense to a whole society?
- Solution: Mechanical clocks and clock towers. The people who came here were familiar with the concept of tracked time, so they’ll come up with a way to artificially track it here.
- New problem: Who builds and maintains these devices?
- Solution: A clockmakers guild with specialized knowledge.
- New problem: That guild now has political leverage! If they withhold their services, a settlement loses its ability to coordinate, or a neighborhood or factory becomes out of sync, creating annoyances for shift management and trade.
- Solution: The city government regulates the guild, which probably doesn’t do wonders for the tension between the two entities. Which, you guessed it, could be another problem.
One constraint. Layers upon layers of worldbuilding. And I could keep going, because each new solution opens more questions. You never run out of material because the constraints keep generating it. And if you run an idea chain to a natural conclusion, or get bored of it, or it’s no longer useful, walk back up the chain and branch out. I imagine the tidal locking causes many strange problems beyond just clocks, no?
Forcing Creative Solutions
When there is no immediate and obvious answer to your problem, or it’s one that isn’t fun, you have to find a better one. This is where constraints push you past the generic and the boring, and towards making an exciting setting.
Every fantasy world has cardinal direction, such as north, south, east, west. Those come from Earth’s relationship to its sun and its magnetic poles. Maelstrom, though, doesn’t have a meaningful sunrise or sunset, and magnetic poles aren’t a thing that people have grown to use as a tool. So what do people use for navigation instead? We don’t want to make it particularly convoluted or complex, and frustrate players or readers, but it should make some sense.
The answer I arrived at was storm-relative navigation, since it’s a perpetual feature of the planet. Stormward (toward the eternal storm at the substellar point) functions as a “north” direction for the inhabitants of the continent that Landfall is on. Darkward is self-evident, and windward/leeward (relative to the prevailing winds flowing from the storm). It’s intuitive for the inhabitants, it’s different from the expected fantasy standard, and it emerged entirely from that first constraint. I didn’t set out to invent a navigation system, but the world demanded one.
Create Interconnected Systems
Constraints ensure that different parts of your world affect each other. It’s sort of the same idea as the butterfly effect. If your geography dictates what the climate is like, and your climate shapes your available agriculture, and your agricultural outputs drive your economy, and your economy influences the politics of the kingdom… You can see how changes in any one area ripple through all of them. A butterfly flaps its wings and on the other side of the world, something crazy happens as a knock-on effect.
This connection and interplay is what makes a world feel real. Players and readers may not consciously track every single place where the systems in your world tie together, but they can feel when it gels. When something changes in one place and the effects show up somewhere else, the world is going to feel alive, rather than like a backdrop painted for a single scene.
Choose Good Constraints
Start with “What If?”
The best constraints begin with a single, specific question. Not “what if everything were different?”. That’s just infinite choice again. Something focused enough to have clear implications is better for your “what if” question.
“What if a planet were tidally locked?” worked for me. But maybe “What if magic required line of sight to the stars?” or “What if the dominant civilization had no written language?” could be intriguing prompts to begin with. Each of these immediately suggests dozens of consequences worth exploring.
Follow the Implications
This is where discipline matters. Take your time selecting a base constraint, but then commit to it. Research or reason through the cascading effects, even when they’re inconvenient. Especially when they’re inconvenient, because that’s where the interesting stuff lives.
If your planet is tidally locked, you don’t get to hand-wave the temperature struggles or the lack of a day/night cycle when they become awkward for your story. Those awkward consequences are the point. Embrace them, and they’ll give you material you never would have invented on your own.
Embrace Trade-offs
Every good constraint should close off some possibilities while opening others. If putting a rule in place in your world doesn’t eliminate any storytelling or worldbuilding possibilities, it’s not really a constraint. It’s just flavor text.
The test is simple. Just ask yourself, if you removed the constraint, would anything in your world change? If the answer is no, the constraint isn’t doing any real work. Find one that does.
Practical Exercise
If you want to try this approach:
- Pick one major constraint for your world. Something physical, cultural, or magical. Whatever interests you most.
- List 10 direct consequences of that constraint. Don’t filter for things you want to pursue right now, just follow the logic.
- For each consequence, identify one problem that inhabitants of your world would face.
- For each problem, develop a solution. It can be rooted in culture, technology, magic, biology, whatever fits.
- Identify what new problems those solutions might create.
By the end of this exercise, you’ll have a tree of worldbuilding details that are all logically connected to each other and to your central constraint. That’s more coherent content than most “anything goes” brainstorming sessions can produce.
Tips on Constraints
Avoid Gimmick Overload
It’s tempting to pile on every cool idea you encounter. A world with tidal locking and a hollow core that has something living in it and sentient clouds and time-traveling dwarves sort of passes beyond the realm of creative and just feels cluttered. Each constraint you add should interact with the ones already there. If a new element doesn’t connect well to your existing framework, it probably belongs in a different world.
Inconsistent Application
Building a world with good constraints but selectively ignoring them when convenience dictates is worse than not having them. Your audience (whether readers or players) will notice, and it undermines the solidity of the world. Their ability to suspend disbelieve when met with the strange is shaken. If you’ve established that, for example, magic requires starlight, don’t have a wizard casting spells in an underground tunnel without a very good explanation. And even with a good explanation, don’t do it often.
Show, Don’t Tell
Constraints should be shown through their effects, not lectured about. Show, don’t tell. You don’t need a chapter to explain the details of tidal locking in a book, or a scientist character to bore the players to tears in a tabletop session. Instead, you can just sprinkle in details, where a character indicates direction by saying “stormward” instead of “north,” and a reader or player who thinks “oh, that’s interesting” rather than “oh, the author is showing off their nerdy science research.”
The worldbuilding should feel natural. The people in the world just exist in it, and as a consequence of it. They don’t frequently explain how gravity works to each other, it just is how it is. Your constraints should work the same way.
Conclusion
Constraints aren’t limitations on your creativity. Starting with even just a few key concepts or clear rules about what’s possible and what’s impossible in your world can provide an opportunity for a cascade of great details. Even just with a simple idea, you can build out a web of logically related people, places, things, and systems. The key is choosing constraints that create fun problems, and then following through on all the most interesting consequences.
This sort of approach is going to make your world feel like it’s a whole, like your characters and plots are enmeshed within a real society in a real place. Fantasy worlds can often feel trope-y, generic, or too random to make sense. But the world built from good constraints can be yours.
Thanks, and see you at the table!
— Asherion