Hard vs soft magic is a topic which comes up a lot in fantasy writing. There isn't much of a consensus on exact definitions beyond the rather vague: “Soft magic has loosely defined rules, while hard magic's rules are more concrete.” There are plenty of much more specific definitions out there, from various different sources, however I felt it best to discuss how I personally define the magic hardness spectrum to give any readers of this project a better understanding of how I plan on approaching things.
Many definitions rely on what the reader knows or understands. I'm not particularly satisfied by these definitions, as it implies that a magic system changes in hardness as the reader reads, when in reality the magic system hasn't changed at all. Instead, I prefer to define hardness based off what the author knows. This way, a hard magic system is not confined to expressly informing the reader of its mechanics, which can lead to excessive exposition if done even slightly wrong, and can instead tease out mechanics implicitly.
Additionally, a lot of definitions tend to focus on how clearly defined the limitations or restrictions are. This again strikes me as unsatisfactory. A magic system can be extremely well defined, with very strict rules, but still be open-ended. For example, in one of my other projects currently titled The New Dawn Franchise, which you can read a little bit about by visiting my “Author Site” project linked on this project's home page, my magic system is essentially a science. Now, to be clear, I don't mean this in a “magic is just really advanced science which we don't understand yet” sense. In fact, I really hate that trope, because I feel like it's just an excuse to hand-wave explanations a lot of the time. But instead in the sense that the entire thing is extrapolated from a small set of well-defined axioms, is repeatable and can be empirically tested. I have been able to justify any type of spell, ritual, enchantment, etc. that I have ever tried to.
In a video from about a year ago by Shad M. Brooks, on his YouTube channel Shadiversity, titled MAGIC in fantasy, soft magic vs hard magic: FANTASY RE-ARMED, he discusses a similar case, using the example of The Wheel of Time. In this instance, he says that it is a softer system than people realize, because they can always introduce new weaves (spells in the Wheel of Time universe) and therefore the system is not limited in the same manner as a hard magic system. This gets at the crux of why I think what is understood by the reader is a bad metric by which to measure the hardness of a system. Information simply not having been introduced yet should not affect the hardness of a system. Later in that video, he then goes on to say that in one of the later books one of the characters discovers a new weave at a pivotal moment, but it is saved from being a deus ex machina because they discover it via logical reasoning consistent with the known magic system. Now, full disclosure, I have not read any of The Wheel of Time, but from just these facts alone, I would argue that this is exactly what makes it a hard magic system. The fact that unknown elements of the system can be extrapolated via logical reasoning given the known rules.
In that other project of mine, which I mentioned above, the magic system essentially consists of a concept of magical energy, the idea that that energy has certain properties somewhat akin to a waveform which you would use to describe a sound or electromagnetic energy, and the ability to manipulate that energy and change its properties. While there are a few additional rules or axioms which more tightly define how this happens, I have built an extremely hard magic system off a very simple set of properties and axioms. Now, all that being said, in that project I don't intend to explain the vast majority of the underlying mechanics, as it would probably require a two-hour lecture to really give people a basic rundown as to how it all works at the lowest level. However, built on top of the general system, various magical practitioners have found differing techniques and methods, most of which were discovered without having any underlying understanding of the overall magic system. This would be similar to how humans discovered how to forge iron, before we discovered precisely how heat effects the atoms in the metal allowing them to become pliable, reshape or harden. In fact, long before we even knew that atoms existed at all. Because of this, I can give explanations about how a particular spell works, while not necessarily going into explicit detail about the exacting underlying mechanics.
I have always preferred to work with harder magic systems because regardless of whether it is explained explicitly to the reader. If you, as the author, understand the rules, then you will have a much easier time maintaining internal consistency with your work. Even when things don't directly contradict one another, if the author doesn't have a strong grasp of a system themselves, they can end up with various elements of a system which just don't feel right, which can be off-putting to a reader.
Despite the fact that I prefer to define the hardness of a magic system based off of what the author understands, as opposed to what the reader understands, I do believe that it should generally be apparent to the reader what the hardness of the system is, as this is what allows you to actually utilize the magic system in solving problems in the story. I believe Brandon Sanderson has a quote where he puts it much more eloquently, but essential the better of a grasp the reader has on your magic system's rules, the less cheap if feels when it fixes a problem. This is why we can generally still discuss how hard or soft a magic system is based off of reading the book, watching the movie, etc. While I don't believe that explaining those rules is necessary for a magic system to be a hard magic system, from a technical perspective, I do believe it can be critically important from a plot perspective. In order for your reader to proficiently follow along with your story, they need to have some understanding of the mechanics of the world it is being told in. As such, if you are working with a hard magic system, but the reader isn't aware of that, and for them it feels soft, that is a failure of the writing to effectively communicate that fact.
This brings this around, back to the initial supposition that a magic system is not defined by the reader's understanding. Instead, the exact opposite should be true. The readers understanding should be informed by how hard or soft the magic system is. I should note that there may be exceptions to this rule. For example, if you whish to use a hard magic system for more thematic purposes, which is typically how soft magic systems are more often used, then neglecting to communicate the concrete rules of the system poses less of an issue.
Closing this out, I would like to address that I have mostly focussed on identifying hard magic systems thus far. One reason for this is that magical hardness is a spectrum, so you are not so much identifying if it is hard or soft, but rather the level of hardness, making identifying hard or soft one and the same. The second reason for this is that I am much more comfortable working with hard magic systems, as I've always strived to push for as much internal consistency as I could. That being said, in this project I do want to try exploring softer magic systems. I am hoping to use them to explore more conceptual facets of worldbuilding, while also seeing how these more vague forces would effect a world. When a magic simply cannot be well understood, how would that change the way people use it? I look forward to seeing how all that plays out.
- Michael