The Four Axes of Power Systems in Writing

Hard vs Soft:

One of my favorite authors of the fantasy genre is Brandon Sanderson, though my first experience reading about him wasn’t actually a book. Rather, I read about a dichotomy he proposed for how to write power systems. 

In essence, Sanderson teaches that there are two major types of magic: Hard and Soft, which are distinguished based on how many rules and limits they have, and how relevant those limits and rules are to the overall narrative. He refers to these frameworks of supernatural powers as “magic systems,” and fans of fantasy literature have since adopted this phrase. In other genres, where powers may be due to mutations or psionics and not magic, fans refer to such frameworks as “power systems.” For the purposes of this essay, I will refer to them by the latter term, as I think it’s a bit more all-encompassing. 

Hard Systems are based around predictability, cost and rules. The audience knows what the magic does, and so do the characters. As a result, deus ex machina and random asspulls are limited, and wins tend to come from strategy, intelligence and clever application of the magic. Series that use this include many of Sanderson’s own Cosmere works (like Mistborn, Stormlight and Elantris), but series such as Avatar: The Last Airbender. 

Soft Systems have very few rules, and what the magic can and cannot do is vaguely defined. Alternatively, the magic does have rules that the author knows, but they never let the audience in on the exact specifics, which can breed speculation and theorizing. Soft power systems can be really good for keeping suspense and solving some problems, but they shouldn’t be used to solve every problem. Examples include Magic in Lord of the Rings and A Song of Ice and Fire. 

Much like how Isaac Asimov has his Three Laws of Robotics, Brandon Sanderson has his Three Rules of Magic, and one of them is that the audience’s understanding of magic is proportional to how satisfying it is when magic solves problems. Thus, a soft system (which is not well understood) is unsatisfying to solve problems repeatedly. When there are no clear limits on what characters can do, it leads to questions, like “Why couldn’t Gandalf send the Eagles to Mordor in the first place?” Even when these questions have answers—which this question does, by the way—the very existence of these questions demonstrates a general lack of knowledge in the fan base that can be frustrating. 

Pseudo-Hard Systems are a term I came up with, though they were mentioned in Sanderson’s original essay. Essentially, these lie at the middle ground between Hard and Soft Systems, being extremely freeform but having some rules here and there to give it the illusion of being Hard. Examples include Magic in Harry Potter, The Dresden Files and Fate/stay night.  

No one of these is good or bad. Each has their own unique advantages and disadvantages, and it’s really all about what you want to do as an author, and what you enjoy as a reader. If you’re someone who enjoys worldbuilding and realism, a Hard system might be the way to go; if you read or write fantasy more for the wonder and awe that comes with the supernatural, a Soft system might be up your alley. If you want to evoke the wonder of a Soft System but need to stop certain plot holes, a Pseudo-Hard System could be a good bet for you. 

However, I will say that I’m personally biased against Pseudo-Hard Systems, specifically when they have a widespread use in the setting. I suppose it’s nothing against the System itself, but I find that authors too often can’t make a Pseudo-Hard System work with the narrative they have in mind. Many authors won’t explain rules until it's narratively necessary, or don’t consider the implications of their system on the rest of the story. Harry Potter was extremely guilty of both: certain spells like Expecto Patronum were first mentioned in the book they were most relevant in, while game-breaking items like Liquid Luck or Time Turners would appear once and never again. 

Another problem with Pseudo-Hard Systems is that writers often set up rules that work more like suggestions, allowing you to bend the rules if you’re “good enough,” which can feel cheap and irritating. Fate/stay night is famous among anime fans and infamous among power system enthusiasts for doing this, where the author introduces a rule and then immediately breaks it. Every Servant has a Noble Phantasm…except for Gilgamesh, who has thousands. Gilgamesh’s chains are unbreakable…and then Berserker breaks it. Lancer’s Gae Bolg never misses…and then it misses. So on and so forth. 

Nebulous vs Rational:

Later on, I was exposed to the fascinating blog of writer C. R. Rowenson. For those that don’t know, discussing magic systems in fantasy and science fiction is kind of Rowenson’s forte. He has an excellent two-part blog post (that I highly recommend checking out) where he explains that, in addition to classifying magic systems as Hard and Soft, he also classifies them as rational and nebulous. 

To explain the two terms, I’ll use his two examples: Mistborn and Superman. 

Rational Systems follow a very specific logic. When these powers are all viewed as part of a larger whole, they tend to follow clear patterns and themes—which is not necessarily the same as following rules. For example, Mistborn’s main magic system is called Allomancy, and it focuses on gaining magical attributes by ingesting metals. Each metal has a particular power, and each metal has an alloy with a “reversed” power. (Example: zinc amplifies emotions, whereas brass dampens emotions.) There’s not just rules to how you get the powers, the powers themselves follow a distinct pattern. 

Nebulous Systems don’t follow the same logic, pattern or theme when viewed as a whole. Take Superman, for instance. We know that Earth has a much lower gravity than what Kryptonians are used to, but how does that let them fly indefinitely? Earth also has a much richer atmosphere, but how does that lead to super breath, or optical lasers, or enhanced hearing, or any number of other things? And how does Kryptonite factor into that? Why would a chunk of his old homeworld somehow take away all his powers if that chunk of Kryptonite is still in the same low-gravity, oxygen-rich atmosphere? 

Don’t get me wrong, Allomancy is a Hard Magic System, and Clark’s powers can also be quite Hard (depending on how good a job the writer does of defining them). That’s not the difference. The difference is that Mistborn’s powers follow a very specific logic, whereas Clark Kent’s powers don’t necessarily have that same rigor. And that’s not a bad thing! 

I’m relying a bit too much on Rowenson’s examples, so I’ll start making some of my own:

• Avatar: The Last Airbender has a very rational system. It’s not just that the powers are clearly-defined (which does make it a Hard system), it’s that all of them are themed after the four elements, a well-known trope in fiction and mythology. Characters can take the powers of each bending art and apply it in ways that make sense. Of course Bloodbending is a Waterbending technique, because blood is mostly water; it makes sense that Metalbending is an Earthbending technique, because metals are made from ores found in the earth; it makes sense that Lightning Generation is a sub-practice of Firebending, as both are highly-concentrated forms of plasma; and so on and so forth. 

• Black Clover has another rational system, but it’s a bit less so. On the surface, it seems to also follow that style of elemental magic. Asta initially seems to be the exception, but it still makes logical sense, because “Anti-Magic” is given appropriate weight within the narrative. However, several of the side characters have abilities that stretch the definition of an “element.” Yuno has wind, Yami has darkness, Charmy has…food and cotton? Klaus has steel, Julius has time, and William has…world tree? It’s not a nebulous system, but it’s not quite as rational as Avatar. 

• Most comic book characters have more irrational, nebulous power systems, mainly because comic book writers tend to group together lots of cool powers that don’t necessarily mesh together. I get that Aquaman can talk to fish and control water because he’s an Atlantian, but why is he also super strong and bulletproof? I get that Vision can shoot lasers using the Mind Stone, but how does that lead to his density shifting? 

• Though, that “comic book irrationality” can also change depending on the series. For example, I recently watched the first season of Invincible, and I found it wasn’t quite as nebulous as most mainstream comics, simply because Robert Kirkman tends to create characters with only a couple of powers. Mark, for example, has super strength, flight and speed, but not X-Ray vision, heat vision, enhanced hearing, or any number of other things that Superman traditionally has. This makes his skillset feel less like a hodge-podge of random abilities and more like a honed set of powers that would actually work great together. 

Like the Hard and Soft idea I discussed earlier, Nebulous and Rational systems aren’t a strict dichotomy so much as they are a spectrum. Neither end is good or bad, it’s all just in how you use them. For the purposes of this essay, I think of them as another axis that we can use to evaluate power systems. 

If you’re keeping track, that means we have four different possibilities for magic systems so far: Hard-Rational, Hard-Nebulous, Soft-Rational and Soft-Nebulous. 

However, branching beyond fantasy literature and comic books, and into other genres and mediums, I found that the lines between soft and hard became increasingly blurred (and, to a lesser extent, the lines between nebulous and rational). Specifically, in the realm of anime and manga, there is a lot of debate among Western fans about where certain power systems fall. Is something classified as “hard” if the powers are very well-defined, but everyone has different powers? Is something classified as “nebulous” if the same mechanism leads to many different powers? Is “rationality” or “hardness” more about internal logic, or system-wide logic? 

Open vs Closed:

For this essay, I am proposing two more axes on which to rate power systems. Do not think of this as a replacement for the Hard-to-Soft axis, or Rowenson’s Rational-to-Nebulous axis, but simply more dimensions by which we, as fans and writers, measure supernatural abilities. The first is the Open-to-Closed axis, with Intermediary in the middle. Choice and potential are the two distinguishing factors that differentiate these two. 

Open Systems, or “Snowflake Systems” as I initially called them, are systems where powers vary from person to person. In much the same way that all snowflakes are unique in the real world, all powers in a given setting are unique. There is almost always one cause for every power, but the actual powers completely differ. Open Systems can have some overlap in powers, especially if it is rooted in genetics (like Quirks, or the X-Gene from Marvel Comics), but for the most part, everyone should be doing completely different things.  Examples include: Stands from JoJo’s Bizarre Adventure, Quirks from My Hero Academia, the X-Gene in X-Men, Devil Fruits in One Piece, etc. 

Writers often like to establish a correlation between one’s powers and their overall personality—not necessarily as a rule of the lore, but as a clever tool to make a character’s design feel more cohesive. Take, for example, My Hero Academia. Bakugo Katsuki is a hot-headed, aggressive with explosive powers, Jirou Kyoka is a musician with headphone jacks hanging from her earlobes, and Shouto Todoroki’s fire-and-ice powers are split down the middle to represent the divided home he came from. 

Open Systems emphasize a lack of choice. You just have the powers you have, and that’s what you get. A series with a good Open System uses this format to encourage creativity and variance in its fights. My Hero Academia has Quirks that, for the most part, are unique to the person, which makes every fight feel unique. A Hard Open system will discourage random power-ups and instead prioritize strategy, whereas a Soft Open System might still have these things. 

Most of the time, this lack of choice is represented by being born with your abilities. Sometimes, your choices are still limited even if you acquire your powers later in life. For example, in One Piece you acquire your powers by eating Devil Fruits. But you can’t eat multiple Fruits to get multiple powers, nor can you eat a Devil Fruit to replace the power you have, so there isn’t much flexibility. 

Closed Systems, or “Pool Systems” as I originally called them, are systems wherein everyone has access to the same basic pool of abilities, or where everyone has the potential to be using the same abilities. In other words, the system is “closed off.” Closed Systems tend to overlap with Limited Systems (which I’ll discuss below). Obviously it would be no good if Joe Schmoe could whip out the highest-caliber, most destructive abilities, so there are still restrictions. These restrictions tend to be emotional state, skill level, and natural proficiency. Examples include: Haki in One Piece, Chi in Dragon Ball, The Force in Star Wars, magic in Harry Potter, etc. 

For example, everyone in Star Wars can use the Force in two basic ways: telekinesis and telepathy, with all other things as an extension of those two. In the current canon, Sith lightning is seemingly the sole exception. There might be certain techniques someone doesn’t want to use—Obi-Wan isn’t likely to Force-choke someone during a fight—but the point is everyone could be doing the same things, if they wanted to. 

Closed Systems gives everyone the same set of tools, but encourages them to find their own style with those tools. Again, we look to lightsaber duels in Star Wars, where many characters use the basic powers of the Force to help them mid-fight in different ways. Yoda uses it to augment his agility; Palpatine and Starkiller make use of force lightning; Cal Kestis uses Force Slow to great effect; and more. 

Even if there are some abilities that not everyone can do, I still feel comfortable calling them “closed systems” if almost everyone can do almost everything. For example, Haki in One Piece is a system based around willpower. Having sufficient determination grants you one of three abilities: Observation Haki (which gives you more awareness of your surroundings), Armament Haki (which makes you or your weapons stronger), and Conquerors Haki (which lets you emit shockwaves that knock out people weaker than you). Conqueror's Haki is only accessible to a tiny amount of the population, but theoretically anyone can do Observation or Armament Haki. That puts Haki slightly lower on the scale than The Force does, but it’s still pretty Closed. 

Intermediary Systems (also called Categorical Systems) have elements of both Open and Closed Systems. That’s a really vague definition, so let me clarify. Intermediate Systems tend to take any people with supernatural categories and sort them into different groups. Within those categories, people can more or less do all the same stuff, but between categories the powers are totally different. Examples: the Six Nen Affinities in Hunter x Hunter, the four Bending groups in Avatar: The Last Airbender, the Ten Orders of the Knights Radiant in Stormlight Archive, etc. 

Intermediate Systems are interesting to analyze. They emphasize a lack of choice about what category you’re born into, but then a lot of choice in how you use the powers of that category. In practice, many Intermediate power systems feel like several different Closed Systems cobbled together, and that’s not a bad thing. Taking bending in ATLA, for example. You have no choice which bending style you are (if you are a bender at all), but within that style there is room for personal expression. You might be born into waterbending, but through waterbending you could heal, bloodbend or even control swamps and plantlife. 

Hunter x Hunter’s Nen is another great example. You have no choice over what Nen category you are born into, and there seems to be a certain element of randomness to it. Yes, there are some loose patterns (such as white-haired Zoldycks being Transmuters and black-haired Zoldycks being Manipulators), but for the most part, it seems completely random. You might be naturally born an Enhancer, but as an Enhancer, you could enhance your speed, your strength, your durability, your weapons, etc. 

So, to summarize, in Open Systems, (almost) no one is like you, and you are completely unique. In Closed Systems, everyone is either like you or can become like you. In Intermediary Systems, only some people are like you, and those people form their own categories. 

Each of these systems will have their own associated tropes because the powers vary so much, so different writers need to adapt in different ways. For example, one of my favorite tropes is the copycat, someone who can copy (if not outright steal) another person’s power. There are numerous examples of this in fiction, including Rogue in X-Men, Chrollo Lucilfer in Hunter x Hunter, Yuta in JuJutsu Kaisen, Amazo in DC Comics and anyone with Ximic in Lorien Legacies. They’re always a bit terrifying because they break the rules of the universe, which is why characters like Chrollo or Blackbeard from One Piece are such good villains. However, I also acknowledge that this is a trope exclusive to Open and Intermediate Systems, because copying someone’s power in a Closed System means nothing when everyone already has access to the same basic powers. 

At the same time, there are certain tropes pertaining to students and teachers that simply wouldn’t make sense in a world with an Open System. For example, the scenes of Obi-Wan training Luke in Star Wars only make sense because the Force functions the same for both of them; if it manifested in completely different, personalized ways, there wouldn’t be much insight Kenobi could give him. Thus, in series with Open Systems (like JuJutsu Kaisen) or Intermediary Systems (like Hunter x Hunter), the mentors can only teach the most basic parts of the system. 

Limited vs Unlimited:

The other axis I am proposing is the Limited-to-Unlimited axis. This axis is quite smaller and has a lot more overlap with existing systems I’ve discussed, but I still thought it was important to mention. Whereas Soft vs Hard determines the rules of the system; Nebulous vs Rational determines the cohesiveness of the system; and Open vs Closed determines the uniqueness of members of the system and the amount of choice they have; Limited vs Unlimited deals with the quantity of powers a system has. 

Limited Systems are ones with a small, predetermined amount of powers available to everyone in the system. A Limited System is almost always a Hard System: after all, Hard Systems are all about rules and limits, and a Limited System is putting a clear cap on what can and can’t happen. Examples include the aforementioned Surgebinding and Bending, plus many of the abilities we seen in Dune, Furycrafting in Codex Alera, Hemalurgy in Mistborn, Awakening in Warbreaker, Hamon and Spin in JoJos, Breathing Arts in Demon Slayer, etc.

Unlimited Systems are the exact opposite. Here, there is either a very large amount of powers, or no upper limit on the quantity of powers whatsoever. Unlimited Systems are almost always also Open, as there are a theoretically infinite number of unique powers as long as there are unique members of the system. Examples include the aforementioned Quirks and Stands, Drives from BlazBlue, Semblances from RWBY, Ether Gears from Edens Zero, etc.

Semi-Limited Systems lie in the middle, which can happen one of two ways. First, there’s a finite amount of powers, it’s just a very large amount, like in Arcane Ascension. Second, there’s a smaller set of powers, but an almost infinite way to apply them. 

One interesting side-effect of this classification is the effect it has on choice and freedom, which I mentioned were the distinguishing qualities of the Open-to-Closed axis. It is theoretically possible for a system to be both Unlimited and Closed, which means that almost anyone can do almost anything. Writers who crave a system with unlimited powers  and a large emphasis on skill circumvent this issue by creating a system where the characters can create their own powers. We can see this in the Magic of Fate/stay night, The Dresden Files and Harry Potter, as well as the Nen of Hunter x Hunter. 

I absolutely detest this trope. Systems that are both fairly Closed and fairly Unlimited tend to also be Pseudo-Hard, and they skip over a lot of the process for creating powers, which raises lots of questions. 

How does one create extremely complicated powers? Why aren’t our protagonists constantly creating new powers as the plot demands? If the protagonists do create their own powers, why are they always exactly as weak as the narrative needs them to be to keep the story suspenseful? Now matter the answers to these questions, they’re never satisfying to me. I much prefer stories where characters are stuck with whatever power they got, and have to rely on strategy, clever application or merely just expressing their tools in a new way. 

Handling Multiple Power Systems:

Writing of individual power systems can already be challenging enough, but some absolute masochists of writers want to write multiple. For this, my biggest advice is to make the systems incredibly different from one-another, so they can’t be mixed up. It would feel redundant if one system is technically identical to the other, because then there would be no reason for the second to exist. Ask yourself the following questions: 

• What powers are offered by the systems?

• How are the powers offered by each system distinct in their method and application?

• When the systems are introduced in the story?

• Which groups can use which systems?

• Are these systems Hard or Soft?

• Are these systems Open, Intermediary or Closed?

• Are these systems Nebulous or Rational?

• Are these systems Limited or Unlimited?

• How powers are granted in the system?

• What costs or conditions are required for the system?

One Piece does a good job of this. Its two power systems are Haki and Devil Fruits. Devil Fruits are an Open System: each Devil Fruit user has completely different abilities (ranging from elemental control to shapeshifting and anything in-between) at the cost of being unable to swim, but the nature of Devil Fruits are totally mysterious. Haki (as previously explained) is a Closed System based around one’s willpower. There are three main types of Haki, and almost everyone of significance has learned the first two types (Armament and Observation). 

JoJo’s Bizarre Adventure has three power systems, but they only work as well as they do because they are all introduced at different points, in different ways, and get proper time to shine. 

• Hamon is a Closed System. Anyone can use it, so the distinguishing factor that separates a novice from a master is how creative they are with it and how much training they have. Hell, even Pillar Men can use it, despite Hamon being designed to kill them. It appears in Parts 1-4, but only really has plot relevance in Parts 1 and 2. 

• Stands are an Open System. The massive variety allows for Araki to get super creative, and they appear in Parts 3-8, eclipsing virtually everything else. Some people are simply born with Stands, others acquire them later in life via exposure to a Stand Arrow or parts of the Saints Corpse. 

• Spin is only in Parts 7 and 8, and appears to be a Closed System, but I say “appears” because we only see a handful of people use it. Nevertheless, it seems to be an alternate universe equivalent to Hamon, with sufficient training and creativity being the main things that separate skill levels. 

How to Write These Power Systems, and Worldbuilding:

So, now that we’ve laid out what kinds of power systems exist, let’s discuss which ones would work best for you. 

If you are the sort of writer who prefers variance in fights, an Open System is almost certainly the way to go. It’s very nature guarantees that every fight is totally different, because no combatants have quite the same abilities. On the other hand, an Open System can become hard to write in the long-term, depending on the author. Some writers might have trouble writing that many unique abilities for that long. If this worry concerns you, it might be best to stick with an Intermediate or Closed System. 

If all of the abilities that you are coming up with are quite similar, it might be a good idea to stick with a Closed System, that way you can relate everything back to the same general base. It also keeps things simple and easy for both you and the audience to remember. 

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A good writer doesn’t treat their power system and the world they developed as two separate entities. Some of the best power systems are great not just because they are well thought-out, but because they expertly work with their locations and the common way of life. 

For example, in Avatar: The Last Airbender, bending is an Intermediate System, and it is a way of life. These categories of bending (Fire, Water, Earth and Air) correspond to entire nations with their own culture, values, government and roles in the story, and bending is used all over the world, from the lowest peasant to the most powerful monarchs. The 4 bending styles also power all kinds of transportation, weapons and machinery, a fact that is fleshed out even more in The Legend of Korra. 

Mistborn is another great example of a power system that’s great because of the world it inhabits. Allomancy has already begun shifting the landscape of the world in the Wax and Wayne sequel series, and Sanderson has discussed how he intends to write two more Mistborn trilogies: one with computers powered by Allomancy, and one with spaceships powered by Allomancy. 

Funny enough, while I acknowledge it is a brilliant series, this dissonance between the power system and the setting is one of the only problems I have with Hunter x Hunter. Again, it’s a genius story, but Nen is this weird “open secret” amongst the world, where several individuals are in obvious contact with Nen but can’t quite figure it out. That’s partially because Togashi introduced Nen with the intent it would only be used by the upper echelons of this world, but then quickly made several story arcs where Nen was used in public places. Heaven’s Arena is one of the most jarring examples of this, wherein Nen is obviously being used on the top floor yet the commentators and the audience never seem to figure it out, and an explanation is never given for what they think is happening. 

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In closing, I just want to reemphasize that I love learning about, writing about, and creating new power systems. I think the whole process is fascinating, but as someone who often struggles to identify off the top of my head whether a system is Hard or Soft, Rational or Nebulous, I simply wanted to create a new means of classification for fans.