If you’re looking for that one crucial element that sets DC comics apart from its biggest rival, Marvel, you need to look no further than its rich history with the concept of a Multiverse. Sure, Marvel has dabbled in the idea of alternate worlds and fractured dimensions (most notably in its 2015 worlds-destroying super event Secret Wars), but the very nature of DC’s multiverse is deeply intrinsic to the very nature of the shared universe of Superman, Wonder Woman and Batman -- among many others.

RELATED: A Marvel Multiverse Primer: 15 Things You Need To Know

From its humble beginnings in the ‘40s to the latest stories currently unfolding, the biggest moments in the history of DC Comics have revolved around the multiverse. It’s been destroyed and created through numerous Crises, traveled through and explored by characters like The Flash, and invested in by creators like Alan Moore, Mark Waid and Grant Morrison. As a concept though, the multiverse can be a daunting prospect. It pops up in many stories over the years, and has been the backbone of almost every major event since 1985, but what do you really need to know before you dive in? We’re here to help.

15 52 WORLDS

The DC Multiverse

For a concept that is built around the idea of multiple worlds beyond your imagining, DC’s multiverse is actually surprisingly well structured. In fact, thanks to Grant Morrison and his series Multiversity, there’s even a map! You can learn a lot by studying this map of what’s been accepted in canon as the current iteration of DC’s multiverse. It’s so crucial that the exact map was even studied in the first issue of 2017’s Dark Knights: Metal by the characters themselves.

Exactly how these characters came to create such a document has yet to be revealed, but for us readers, Morrison crafted an engaging series that explored the 52 words created and structured following the last major crisis -- entitled, appropriately, Final Crisis. The multiverse has been much bigger and much smaller over the years, but for the moment there are 52 Worlds.

14 IT’S OLDER THAN YOU THINK

While the current iteration of the multiverse only goes back as far as 2008’s Final Crisis, the actual concept of a multiverse in DC Comics goes back a lot further. The shared universe nature of superhero comics was introduced in the 1940s, where the Justice Society of America brought characters together from various comics. But it wasn’t until Wonder Woman in 1953 that the idea of alternate worlds was explored.

In Wonder Woman #59, Diana travels to a “mirror” world that exists in parallel to our own. There she meets her alternate self, called Tara Terruna, and this world -- later designated Earth 59 -- was almost identical to Wonder Woman. While the multiverse will be expanded on and explored in more depth in later comics, this is where the construct first took shape.

13 THERE’S A DARK MULTIVERSE

A dark version of Batman looking scary surrounded by an orange background in Dark Knights Metal.

Bringing us right up to date, Dark Knights: Metal explores the idea that the DC Multiverse -- from its 52 worlds to the Source Wall that surrounds it -- is not the full extent of all existence. Much like modern scientists theorize about matter, antimatter and dark matter in our own universe, it’s revealed that the DC multiverse is merely a drop in the ocean, and that ocean is dark, unknown and evil.

For years, DC Comics were able to explore out of continuity tales about their characters in something called Elseworld tales. These "what if" style stories were said to exist somewhere in the Multiverse, but when Grant Morrison created his map of 52 Worlds, not all of these Elseworlds were included. Were they wiped out in a previous crisis, or do they exist in this Dark Multiverse? The possibilities are endless, but they will be explored in time.

12 COMICS ARE CRUCIAL

superboy prime

Obviously comics are important to the DC multiverse -- after all, its entire existence is in comic book form! However, comics are vital in another, more fundamental way. Ever since The seminal Multiversal story "The Flash of Two Worlds" from 1961, where Barry Allen read about his Earth-Two counterpart Jay Garrick in a comic book before meeting him in a crossover issue, comics have played a role in the formation of the multiverse.

Grant Morrison explored this idea deeply in his series Multiversity. He expanded the idea that each world in the multiverse is represented on another world in the form of a comic book. Not only does this add a unique element to the construction of this cosmic concept, but it brings us into the narrative. After all, aren’t we reading about another universe in a comic book?

11 THE FLASH IS ALWAYS CENTRAL

People don’t give The Flash the credit he deserves. When talking about the strongest characters in the DC Universe, most people think of Superman, Wonder Woman or even Green Lantern and Batman before thinking of The Flash. What Flash has that the others don’t, though, is access to the Speed Force.

The Speed Force is the extra-dimensional energy that powers the majority of the speedsters in DC Comics, and it was this connection to the Speed Force that allowed Barry to jump between universes in "The Flash of Two Worlds" from Flash #123 in 1961. This story kicked off the modern version of what we know as the Multiverse; since then, in almost every vital storyline involving the multiverse, The Flash has played a crucial role.

10 IT’S BEEN DESTROYED MULTIPLE TIMES

crisis-on-infinite-earths-dc-comics

When you talk about major events in DC Comics history, you can't help but mention the word Crisis. The reason is that, ever since 1985’s Crisis on Infinite Earths, almost every massive storyline concerning the multiverse has had the word Crisis in the title. It’s not an inappropriate word, actually. Both Crisis on Infinite Earths and its 2005 sequel Infinite Crisis looked to simplify decades of convoluted DC continuity by destroying the multiverse, and 2008’s Final Crisis brought the whole thing back.

Since then, series like Flashpoint and Convergence have written and rewritten the multiverse, and DC Universe Rebirth #1 implied that characters from Alan Moore and Dave Gibbon’s Watchmen series were somehow manipulating the whole thing. Throw in the fact that in Morrison’s Multiversity, the cosmic construct was nearly destroyed by us the readers (it’s a long story), and the multiverse has definitely been knocked around more than once.

9 FEEL THE VIBRATIONS

Rather than all of these multiple universes existing side by side or even stacked on top of each other, back in the Silver Age of comics, it was revealed that all of these universes exist in exactly the same space, and they can do this because they all vibrate at a different frequency. That’s why The Flash is able to travel between these worlds, because he’s able to use the Speed Force to move fast enough to vibrate at a different frequency to the universe he is in, therefore shifting to an alternate universe.

If that all seems a bit far-fetched, it gets better: it transpires that certain people can tune in to these vibrational frequencies while they sleep, meaning that the dreams they see are actually alternate Earths in the multiverse. This explains how creators on one Earth can write comic books about another. Neat, huh?

8 THE MONITORS OBSERVE ALL

Anti-Monitor

That the Multiverse exists is one thing, but how was it created? Well, in Green Lantern #40 from 1965, it’s revealed that Krona -- a scientist from the planet Oa -- developed a time-viewer that allowed him to see the creation of the universe. His actions inadvertently brought about the creation of all evil in the universe, as well as the creation of multiple universes, as revealed in 1985’s Crisis on Infinite Earths.

Due to Krona’s experiments, both an infinite Matter universe and a singular Antimatter universe were created. This cosmic imbalance was addressed by the creation of the Monitor, a cosmic being who oversaw all of the multiverse, and the Anti-Monitor, who sought its destruction.Their conflict ended in a draw after a million years, but their awakening was the start of the Crisis on Infinite Earths.

7 LIMBO IS A PHYSICAL PLACE

Aside from the 52 physical worlds, there are numerous conceptual constructs that all align together and help build the map of the DC Multiverse. Things like the Sphere of the Gods exist, as does the abstract concept of Limbo. Limbo has only been explored a few times in comics, but it’s as wild and wacky as comics get.

While Limbo was created by Keith Giffen in 1985 for the series Ambush Bug, it wasn’t developed further until five years later in Grant Morrison’s Animal Man, with artists Chas Truog and Doug Hazlewood. Limbo is the place where characters go when they’re no longer used in comics or are removed from continuity. It’s a metafictional concept that saw characters like Mr. Freeze and Ace the Bat-Hound stranded in Limbo because writers no longer used them.

6 THE ROCK OF ETERNITY SITS AT THE CENTER

rock-of-eternity

Ever since DC Comics became owners of Fawcett Comics and its characters -- most notably Captain Marvel, aka Shazam -- the Rock of Eternity has sat at the center of space and time. It’s been mentioned that it was created by the wizard Shazam by merging a piece of stone from heaven and a mating slab from hell and is the prison of the Seven Deadly Sins.

Part of the reason the multiverse exists at all in DC Comics is to house all of the various licensed properties that DC has come to own over the years, so it’s only appropriate that such a prominent location from one of these licenses sits at the center. It’s often visited by the Marvel family, as they all acquire their powers from the Wizard Shazam who lives there, as well as using it as a nexus to travel the multiverse.

5 IT'S SURROUNDED BY THE SOURCE WALL

There is an end to all the things, and at the end of the DC Multiverse lies the Source Wall. It was created in a way by Jack Kirby, who mentioned a final barrier between the multiverse and the Source of all Things. It was only shown on panel in the Uncanny X-Men/Teen Titans crossover series created by Walt Simonson and Chris Claremont.

When it is depicted, it always shows a vast, unfathomably large barrier, within which lie the souls of all those who have tried to pass through. Only a few have passed through and survived, including Superman and The Flash. Highfather and Darkseid, working together, once destroyed the Source Wall, but it was replaced soon after. It’s located on the Multiverse map at the edge of the Monitor Sphere, beyond which is just white space.

4 HEAVEN AND HELL EXIST

As well as Limbo or Purgatory existing, more abstract spiritual concepts exist as part of the Multiversal map, including Apokolips and New Genesis, Underworld and Skyland, and Heaven and Hell. Depicted on the map as sitting beyond the 52 Worlds, they inhabit what’s known as the God Sphere.

It’s an interesting concept, to include these ideas of religious and spiritual places as a plane of existence, seemingly cementing -- at least in DC Comics anyway -- the nature of the afterlife. Also present within this realm are the concepts of Dreams and Nightmares, places explored at great length in Neil Gaiman’s Sandman series. Many Gods and mortals have traversed between Heaven and Earth, most notably The Spectre, who serves as a vengeful spirit of Heaven, and Etrigan, a demon from Hell.

3 THERE ARE SEVEN UNKNOWN WORLDS

Multiversity is a fantastic series that explores different worlds of the multiverse in each issue. One issue, in particular, is fascinating, as it provides a thorough introduction to every one of the 52 worlds of the current DC Multiverse. From the magical twilight of Earth 13 to the disastrous Earth 51 of Kamandi, all are explained.

Entitled The Multiversity Guidebook, Grant Morrison explores all the known worlds and chronicles their heroes. There are, however, seven worlds -- both in the guidebook and on the map -- that are depicted only with a question mark. Whether Morrison did this to add some mystery or intrigue to the multiverse, or whether they were introduced in order to provide future writers with a little freedom to be creative is unknown, but either way, their very nature is compelling.

2 THERE’S A MULTIVERSAL JUSTICE LEAGUE

Justice-Incarnate

Although Multiversity was a series of relatively standalone issues (with a Guidebook in the middle), the first and final issues that framed the narrative told of an otherworldly evil that threatened to wipe out the entire multiverse. This isn’t the first time the multiverse has been threatened and it wouldn’t be the last, but in times of crisis (no pun intended), the only team you can turn to in the DC multiverse is the Justice League.

For threats this magnificent in scale, though, just one Justice League, from just one world seems like a fairly small solution. That’s why Superman of Earth 23 collected a group of powerful superheroes from all across the multiverse and created Justice Incarnate: a super team strong enough to defeat The Gentry and the being that commands them: The Empty Hand.

1 WE ARE A PART OF IT

Ultra beats a villain bloody in DC's Multiversity

With this many universes across the DC Multiverse, it seems only appropriate that there be a universe similar to ours. Well, DC goes one better than that, and in fact, our exact Earth is represented in the Multiverse as Earth Prime. Pre-Crisis, it was one of the infinite numbers of worlds represented, but post-crisis it has only been seen a handful of times. Since 2015’s Convergence event, however, Earth Prime has been fully restored in the Multiverse.

On Earth Prime, there are no superheroes, and in the Multiversity Guidebook, it is designated as Earth 33, and commented on that it is the only universe without superheroes or any alien presence of any kind. The Monitors chose this Earth -- our Earth -- to store the chronicles of the Multiverse, and the form they chose to house these chronicles? You guessed it: comic books.

What do you know about the DC multiverse? Share your findings in the comments!