Multiverse Theory 101
The structure of the Multiverse is hard to describe, and even harder to grasp even if it was described properly. The scientist in me says I should attempt to describe different theories of the Multiverse. The wizard in me knows that none of them are exactly correct. Theories, after all, are just tidy little boxes we use to contain something infinitely messier than our minds can handle. However, to better understand the various worlds of the multiverse, it is useful to know these theories, so we shall start there. Fair warning: your head may hurt a bit. Mine certainly does, and I’ve been doing this for eons.
The Near Planes Theory
Alright, I use this term loosely, but let’s say your plane is the center of all existence. Yes, we all know it isn’t. The universe has a distressing tendency to not revolve around any of us, despite our best efforts to convince it otherwise. But from your perspective, it is the center. Throughout your history, there are branches and changes. An infinitesimal number of branches and changes, really, but most of those changes overlap and converge in ways that would make a mathematician weep with joy or terror, depending on their temperament.
There may be one world that has evolved slower for whatever reason, but it is still essentially your world. A world where perhaps the printing press was invented fifty years later, or where tea was discovered before coffee, leading to entirely different approaches to international diplomacy. Oddly enough, languages tend to evolve similarly, and even countries tend to exist in roughly the same places with roughly the same borders. There may be minor differences (perhaps France is called Gaul still, or maybe England never quite got over being called Britannia) and even major differences, but some things are just sort of… set. Fixed points, if you will, like cosmic tent pegs holding reality in roughly the same shape.
For the most part, these planes are boring. Yup, I said it. Who enjoys seeing what history would be like with one minor change? “Oh look, in this world, Napoleon was slightly taller and conquered Russia successfully.” Riveting stuff, truly. Oh, actually, I know a lot of people who do find this fascinating. Historians, mostly, people who argue about alternate outcomes at dinner parties, and the most opinionated - historical reenactors. Yes, those could be interesting worlds to explore… if you enjoy that sort of thing. I suppose someone has to.
However, the similarities may not be as similar as you think. Let’s take your realm, for example. How do you know I was talking about your realm? Well, in truth, most anyone who picks up this journal will find this statement applies to them. It’s one of those convenient universal truths, like “traffic is always worse when you’re running late” or “the other queue always moves faster.”
Your realm seems normal to you. Sure, there may be some darkness to it (strange disappearances, unexplained phenomena, politicians who seem unusually adept at avoiding direct questions) but to you, it is normal. If you shift along the spectrum of worlds, you may find a realm where magic and darkness lie just below the surface, hidden like the electrical wiring in your walls. I often call these worlds Dark Fable worlds. They are worlds you know, but there is something more that lurks beneath the veneer of mundane reality. The strength of the Shadow Realm is much higher in Dark Fable worlds, seeping through like damp in an old basement.
On the other hand, you can also stumble upon Light Fable worlds, where spirits are both tricksters and helpers, like having a household full of invisible relatives with questionable senses of humor but ultimately good intentions. These worlds are often idealized variations of your world. Maybe not in the world itself (wars still happen, people still stub their toes on furniture - arguably, probably more so due to the trickster nature of it all) but the wonder of magic sits around each corner like a cat waiting to trip you, except in a delightful way.
These are all worlds that are close to your world, clustered together like books on the same shelf. However, as you go farther along the spectrum, the worlds become stranger and stranger. Soon you have stumbled upon worlds where evolution has taken completely different turns, creating multiple races, systems of magic that would make your head spin, and societies organized around principles that would seem utterly foreign. Imagine a world where cats developed opposable thumbs first, or where mathematics was discovered by poets instead of philosophers. Different, but not necessarily better or worse - just… sideways to what you know.
The Overlapping Realms
Each of these worlds are essentially overlapping, like sheets of paper laid one atop another, and no, if you immediately think this has to do with vibrations and quantum realities, you are wrong. I’m looking at you, theoretical physicists. Stop trying to make everything about waves and particles. However, the Material Realms are not the only worlds overlapping with yours. Within each world there exists both a Shadow Realm and a Spirit Realm, pressed against your reality like pages in a book that have gotten slightly stuck together.
While dark energies tend to gravitate towards the Shadow Realm, and light energies toward the Spirit Realm—in truth, these are not opposite sides of the same coin. I actually think they might be the same coin, viewed from different angles, or perhaps different aspects of the same fundamental force. From your point of view, though, they would feel like entirely different realms, as different as ice and steam despite both being water.
They exist side by side with your reality, so close you could reach out and touch them if you knew where to put your hand. The Spirit Realm being the most interesting to most people—you may accidentally stumble one day into a bathhouse run by spirits who insist on payment in memories rather than coins, or you may leave out offerings for spirits to help you find your lost keys, and surprisingly, they do! The spirits, it seems, have an odd fondness for small acts of kindness and an inexplicable knowledge of where you left things.
The Shadow Realm, on the other hand, is where beings and people go to hide. Not necessarily evil beings (though yes, some of those too) but anyone who needs to exist just slightly outside normal reality. Spies, exiles, people avoiding their taxes, creatures who find sunlight disagreeable, and anyone who has ever wished they could just disappear for a while. It’s remarkably accommodating, though the décor tends toward the gloomy side.
I often wonder if our ideas about death and the afterlife come from glimpses of these realms. If your heart is heavy when you pass from your world, you may fall into a small pocket realm within the Shadow Realm—and yes, there are indeed pockets of demi-planes within these realms, like rooms within rooms within rooms. Many of these shadow pockets are ruled by fiends whose names I shall not put here, partly for your safety and partly because they have a disturbing tendency to show up when you say their names three times. If your heart is light when you pass, you probably fall into a pocket of the Spirit Realm, where the tea is always perfectly brewed and someone is usually playing pleasant music just out of sight.
Once again, if you insist this is all about vibrations, you would be wrong, but you could probably think of it as different frequencies if it helps you sleep better at night. Think of it like radio stations—same device, different channels, and occasionally you get interference between them.
This gives us three very near planes to consider: the Material Realms (your realm with variations both near and far), the Shadow Realm, and the Spirit Realm. Keeping up yet? Probably not, and that’s perfectly fine. Even I get confused sometimes, and I’ve been wandering between them for longer than most civilizations have existed. Just knowing they exist is helpful for describing how some magic and abilities work, and why sometimes you catch glimpses of things that shouldn’t be there out of the corner of your eye. Spoiler alert: they probably are there, just not quite in the same realm as you.
The Hedge
With all this in mind, it’s important to note that there exists something I like to call the Hedge. Have you ever watched one of those fascinating ant farms behind glass? You know the ones where you can see all the tunnels connecting in every which direction, creating a maze that somehow makes perfect sense to the ants but looks like absolute chaos to everyone else. There are levels, certainly, but there are also shortcuts between those levels that seem to defy any reasonable architectural planning.
Well, throughout the Multiverse, there exists just such a shortcut system. It is simultaneously the most useful and the most dangerous path anyone could ever take. The Hedge is a realm unto itself, one of those cosmic tent peg realms that truly exists only once, but that singular existence stretches everywhere at once. Think of it as the Multiverse’s back-alley system, if back alleys were prone to spontaneous rearrangement and populated by beings who’ve given up on the concept of linear thinking.
This realm is where many of your world’s stories about the fae and other strange creatures originate, at least partially. It’s rather interesting, actually. In worlds where elves evolved naturally alongside humans, they don’t tend to worry much about distant, mysterious fae when they have perfectly tangible, local fae living next door who borrow sugar and return it as crystallized moonlight. But in worlds like yours, where magic hides behind the curtains of mundane reality, the Hedge bleeds through in stories and legends.
The Hedge itself defies easy description because it refuses to stay consistent long enough for proper cataloging. It’s populated by beings I can only describe as brilliantly mad, creatures and people who’ve adapted to survive in a realm where standard physics threw up their hands in frustration and wandered off to find a nice, predictable dimension to govern instead. These inhabitants have learned to navigate a world where reality is more of a suggestion than a rule, where cause and effect engage in philosophical debates rather than maintaining any reliable relationship.
The Hedge connects all worlds through an impossible network of paths that might be forest trails one moment and subway tunnels the next. There are fields that stretch beyond horizons, pocket realms nested within other pocket realms like a cosmic set of nesting dolls, and yes, sometimes even literal tunnels, though I wouldn’t recommend assuming they lead where you think they should. The Hedge has its own sense of direction, and it doesn’t always align with conventional notions of “forward,” “backward,” or “logically toward your intended destination.”
Navigation through the Hedge requires a particular kind of thinking that I can only describe as “sideways logic.” Those who try to apply normal reasoning tend to find themselves walking in circles, or worse, walking in shapes that don’t have names because geometry hasn’t invented them yet. The successful travelers are usually those who’ve either gone slightly mad in useful ways, or who possess the rare ability to think like the Hedge thinks, which is to say, not in straight lines but in spirals, loops, and the occasional interpretive dance.
The Mad Realms
Now, let’s take a step further into madness, shall we? There exist realms in which madness is the governing logic, at least to your mind. To the creatures that live there, the madness is perfectly normal and sensible. It’s rather like capitalism, really. If you’re raised in it your whole life, you may find it completely reasonable, but if someone starts to question the underlying logic, you begin to see that the entire monetary system is simply elaborate, collective madness.
Actually, no, that’s not quite fair to capitalism. Money does serve a useful purpose. It’s really quite difficult to keep track of favors, so currency acts as a tangible substitute. Stock markets, on the other hand, those are absolutely run by goblin fae who make up all the numbers while laughing that you actually believe any of the money exists. An entire system based purely on collective belief. Terrifying when you think about it, but I suppose that’s beside the point.
However, I digress, as I often do when contemplating economic systems. These distant realms are better known as the Mad Realms, because they are so fundamentally different from your center-of-the-universe perspective that absolutely nothing makes sense. The laws of physics there don’t just bend, they engage in elaborate practical jokes. Mathematics occasionally gets drunk and forgets how to count properly. Cause and effect have had a falling out and refuse to speak to each other.
The real problem with the Mad Realms? The creatures from them often enjoy playing in other realms, though “playing” might not be the right word. “Existing catastrophically” might be more accurate. At least, it appears that way to those of us who prefer our reality with a bit more structural integrity. Cultists and followers will sometimes find these beings and attempt to worship them, though honestly, most Mad Realm entities couldn’t care less about worship. However, once these minor beings manage to say their names correctly (which is no small feat, given that Mad Realm names tend to exist in seventeen dimensions and sound like the equivalent of a sneeze), they might as well reward such dedication by casually destroying everything in the immediate vicinity.
Think of it this way. Let’s say that ant colony I had you envision earlier (see how I cleverly tied this back to the previous section? I am good like that) suddenly rearranged their tunnels one day to spell out your name in perfect cursive. Once you realize it is cursive, you would be impressed, naturally. Maybe you give them a little sugar as a reward for such artistry. Then one day, through some miracle of evolution and determination, one ant manages to speak in your language. It’s very difficult to hear, like listening to someone whisper through several layers of cotton, but you catch a few words. It wants more sugar. Simple enough. You leave some sugar crystals and feel rather pleased with yourself for this interspecies communication breakthrough.
Then one day, your favorite ant gets your attention again. But instead of asking for something simple like more sugar or perhaps a tiny ant-sized umbrella (you of course have already complicated how to make one), it asks for something far more complex. It wants another ant to love them. Now, you may not understand the intricacies of ant romance, but this is your favorite ant, the one that learned to speak your language. You want to help. You think about it with your vast, incomprehensible-to-ants intelligence, and you realize that if you simply destroy all the ants except this one and the ant it wishes would love them, then of course love must naturally follow. It’s basic logic, really.
After accomplishing this task with the casual efficiency that comes from being several orders of magnitude larger than your subjects, you notice that your favorite ant is looking at you in absolute horror. It has just realized that it was the unwitting cause of the complete destruction of its entire civilization. Meanwhile, you’ve already gone back to drinking your tea without a care in the world, rather pleased with your problem-solving skills.
Maybe one day you’ll check back to see if the two surviving ants have managed to repopulate their colony. Of course, it’s only then that you remember ants don’t actually experience love or reproduction in the same way you do, and their entire social structure was based on collective cooperation that you’ve just obliterated. You begin to wonder what the ant was actually asking for when it used your word “love.” Perhaps it meant something entirely different in ant-speak, like “additional tunneling support” or “protection from the neighbor’s cat.”
But by then, it’s far too late for such considerations.
This type of well-intentioned cosmic horror is perfectly normal behavior for creatures of the Mad Realms. They operate on scales and logic systems so fundamentally different from ours that even their kindness can unravel reality as we know it. This is why visiting the Mad Realms will, quite literally, drive you insane. Your mind simply isn’t equipped to process their version of cause and effect, and attempting to do so tends to result in a complete breakdown of your ability to understand anything at all.
My advice? Stay away from the Mad Realms entirely. Some doors are better left unopened, some paths better left unexplored, and some cosmic entities better left uncontacted. There are plenty of other realms to visit where the worst that might happen is you get turned into a toad or accidentally start a small war. Those are the kinds of manageable risks that make interdimensional travel exciting rather than existentially horrifying.
Summarizing the Overlapping Dimensions Theory
Alright students, let’s summarize this theory. All realms exist simultaneously spreading out farther from a central point. Like pages of an infinitely sized book. Additionally, there are pages glued together that represent the Shadow and Spirit realms. Finally, we have put holes through it all (which one should never do with a book…) to have quick connections to it all. These theories are all great, but there are those who will say they are Gooblegok!
The Large Universe Theory
The next theory is a bit simpler to grasp, though it comes with its own peculiar set of consequences for interdimensional travel. This is the belief that all the realms are actually different planets within the same universe. One universe, mind you, but absolutely massive beyond all comprehension. The proponents of this theory argue that since the universe is infinite (and they’re quite insistent about the infinite part), there must be an infinite number of planets scattered throughout its vastness.
This means you won’t ever stumble upon a world where the only difference is that Napoleon was slightly taller and managed to conquer Russia through improved reach. Instead, all the worlds would be vastly, dramatically different from your own.
Now, this raises some rather obvious questions that even the most casual interdimensional traveler might ask. How does one actually travel between these distant planets? What about all those stories of seeing spirits, fae creatures, or other dimensional beings wandering about? If everything is just really, really far apart in normal space, how do these encounters happen?
The Large Universe theorists have thought about this, naturally. They believe there are alternative means of travel that don’t involve the rather primitive method of sitting atop multiple tons of carefully controlled explosives and shooting yourself like an enormous, expensive firework into the sky while hoping it doesn’t decide to explode all at once. Their proposed alternatives include traveling via pure thought (which sounds lovely until you remember how easily your mind wanders), astral projection (leaving your body behind like forgotten luggage), or perhaps having your spirit pulled to another world when you die, which is either the ultimate adventure or the worst possible travel insurance claim, depending on your perspective.
These are all perfectly reasonable possibilities within the Large Universe Theory framework. After all, if consciousness can exist independently of physical matter, why shouldn’t it be able to hop between planets like a cosmic tourist with unlimited frequent flyer miles?
The theory becomes even more intriguing when you consider that there might be Small Universes nested within the Large Universe. Picture civilizations so advanced that they’ve learned to sail the aetheric currents from planet to planet, hopping between interstellar ports like island-hopping in some vast cosmic archipelago. Imagine space-faring vessels that navigate by following streams of pure thought, or merchants who trade in crystallized emotions across star systems. Something that may be utterly impossible in your world becomes perfectly mundane for them, like how you might take a bus to visit your grandmother, except their grandmother lives three solar systems over and has tentacles.
These Small Universe communities might have developed technologies that make interdimensional travel as routine as your morning commute. Perhaps they’ve discovered that consciousness naturally resonates at certain frequencies that allow for instantaneous travel between compatible worlds. Maybe they’ve learned to fold space-time like origami, creating shortcuts that bypass the inconvenient limitations of distance and physics.
The beauty of the Large Universe Theory is its elegant simplicity. No overlapping dimensions, no mysterious realms existing alongside reality, no cosmic tent pegs holding everything together. Just one really, magnificently enormous universe containing every possible variation of existence, all spread out across distances that make infinity look like a reasonable weekend getaway.
This theory is much simpler to understand than the overlapping realms model, which is both its greatest strength and its most suspicious weakness. As most scientists will tell you (usually while adjusting their spectacles in a superior manner), just because something is easy to understand doesn’t necessarily mean it’s correct. The universe has a rather irritating habit of being far more complicated than we’d prefer, and simple explanations often turn out to be woefully inadequate once you start poking at them with actual experience.
Still, there’s something appealingly straightforward about the idea that we’re all just really, really far apart from each other, traveling between worlds through methods that transcend mere physical transportation. It certainly makes more intuitive sense than trying to explain how seventeen different versions of reality can exist in the same space without getting tangled up in each other like cosmic yarn.
But… The Spirit, Shadow and Hedge Exists… So do the Small Universes
Now here’s where my extensive, occasionally painful experience comes in handy. They all exist. Every single one of them. The Spirit Realm, the Shadow Realm, the Hedge, the overlapping near-planes, the Mad Realms that should be avoided at all costs, and those vast cosmic distances filled with impossible worlds. All of it. Simultaneously. I realize this sounds like the kind of answer that makes theoretical physicists weep into their calculators, but I’m afraid reality has never been particularly concerned with making their jobs easier.
I have personally walked through the Spirit Realm, where helpful entities offered me tea that tasted like liquid starlight and solved three of my most pressing problems before I’d even mentioned them. I’ve navigated the Shadow Realm, where beings hide not because they’re evil, but because they find regular reality far too loud and bright for comfortable existence. I’ve survived trips through the Hedge, though I’ll admit I came out speaking in rhymes for a week and occasionally turning purple when excited.
I have witnessed Dark Fable worlds firsthand, standing in the exact same coffee shop I’d visited the day before, except this time the barista was a perfectly pleasant vampire who made excellent lattes and gave relationship advice to lovelorn ghosts. I’ve experienced the mind-numbing tedium of visiting a world that was exactly identical to the previous one I’d explored, with only one small change: they spoke backwards. Completely backwards. Not just the words, mind you, but the entire structure of their sentences. “Morning good, Wanderer!” they’d say, which sounds charming until you realize every single conversation requires intense concentration just to parse basic pleasantries.
That particular world was actually rather fascinating once you got past the linguistic gymnastics, but I’ll admit it was exhausting. Try ordering breakfast when you have to remember to say “eggs scrambled with bacon crispy and toast buttered” and hope they understand you want the standard configuration rather than some bizarre interpretation of your grammatically inverted request.
But I’ve also sailed the aetheric currents between distant star systems, my vessel guided by different waves of light that glittered like jewelry in the void. I’ve lived on worlds made entirely of singing crystal, where the inhabitants communicated through harmonics that could shatter diamonds or heal broken hearts depending on the pitch. I’ve sat in a comfortable chair on an observation deck, sipping surprisingly good wine while watching a star-eater (magnificent creature, really, about the size of a small moon with the table manners of your uncle Bernard who constantly asks you to pull his finger at holiday gatherings) methodically devour an entire planet from a system of seventeen worlds.
The wine was excellent, by the way. The locals had been evacuating for months once they spotted the star-eater’s approach, and they’d left behind their finest vintages. Seemed like a shame to let perfectly good wine go unappreciated just because reality was being fundamentally restructured in the immediate vicinity. Naturally, I had to watch and enjoy the fine vintage.
This means the true theory, the real answer to how the Multiverse actually works, is delightfully, frustratingly simple: it’s a little of both. And also a little of everything else we haven’t thought of yet. The Multiverse appears to operate on the principle that if something can possibly exist, it probably does, somewhere, in some form, and likely in several contradictory versions simultaneously.
The overlapping realms exist alongside the vast cosmic distances. The Mad Realms lurk at the edges of both systems, being universally terrible neighbors no matter which cosmological model you subscribe to. Small civilizations sail between nearby worlds while massive space-faring cultures traverse impossible distances, and somehow both can end up at the same interdimensional tavern on a Thursday evening, arguing about whose reality makes more sense.
It’s rather like asking whether light is a wave or a particle, except instead of light, it’s everything, and instead of two options, there are approximately seven thousand, most of which contradict each other in fascinating ways.
Now that you understand that everything you think you know about the universe is both perfectly correct and completely wrong at the same time, we can finally discuss the practical matter of how one actually gets from here to there across this magnificent, impossible, thoroughly contradictory Multiverse. Because theory is all well and good, but at some point, you need to know which door to walk through when you want to visit somewhere that doesn’t technically exist yet.