- "You think you know how the world works? You think that this material universe is all there is? What is real? What mysteries lie beyond the reach of your senses? At the root of existence, mind and matter meet. Thoughts shape reality. This universe is only one of an infinite number. Worlds without end. Some benevolent and life-giving; Others filled with malice and hunger. Dark places, where powers older than time lie... ravenous... and waiting. Who are you in this vast multiverse, Mr. Strange?"
- ―The Ancient One to Stephen Strange
The Multiverse is the collective term for all parallel dimensions in existence.
Agamotto became the first Sorcerer Supreme to detect the presence of other dimensions within the Multiverse. He dedicated his life to protecting the Earth realm from extra-dimensional threats using magic.
First Recorded Contact
During the 1940s, Humans began experimenting with nuclear energy; during one such experiment performed by Isodyne Energy, a rift was created where a substance dubbed Zero Matter entered this dimension. Eventually, the scientists Whitney Frost and Jason Wilkes became infected with the substance. Frost actively sought more of the Zero Matter and reopened the rift; however Wilkes entered the opening. Upon his return, he described his experience in another dimension outside the Earth realm.
In 2015, Hank Pym gave Scott Lang the Ant-Man Suit he had used in the past. While on a mission with his wife Janet van Dyne, Pym witnessed his partner shrinking into a subatomic size in order to break through a missile's titanium shell and disable it. Although the mission was a success, van Dyne was lost in the Quantum Realm, another dimension where time and space become obsolete notions. Pym, heavily traumatized by this loss, warned Lang about the danger of shrinking to a too great extent and ordered him never going beyond the suit security boundaries.
However, Lang had to undergo the same experience as Janet when Darren Cross, who had built the Yellowjacket Suit, threatened the life of his daughter Cassie Lang. Lang went to Maggie Lang's House and had no choice but to shrink at a subatomic level in order to break through the titanium of the Yellowjacket Suit to disable it, just like van Dyne had done with the missile. Much like her, Lang succeeded. However, he was in turn trapped in the Quantum Realm. As he traveled deeper and deeper inside the Quantum Realm where all time and space was eternal seemingly inescapable, Ant-Man began desperately searching for a way to return home rather than be trapped within there forever. In his resolution to return to his daughter and survive, Lang retrieved a Pym Particle Disk and placed it into the regulator of his Ant-Man Suit. His attempt to return to normal size was successful and he reunited with Cassie.
When questioned later by Hank Pym about his experience in the Quantum Realm, Lang told him that he did not remember anything, to which Pym hypothesized that the human mind was not fit to undergo such experiences.
Attack on the Sanctums
After becoming disillusioned to the teachings of the Ancient One, Master Kaecilius and his Zealots launched a campaign to save the world by offering it as a tribute to the entity Dormammu. After tapping into Dormammu's dimension for power, Kaecilius and the Zealots attacked the London Sanctum, destroying it and part of the Sanctums' nexus in Kamar-Taj in his attempt to break down the mystical shields that protect Earth from the Dark Dimension.
After failing to destroy the New York Sanctum, Kaecilius moved on to Hong Kong, where he was met by Wong and the other Masters of the Mystic Arts. However, the Masters proved no match, as Kaecilius defeated them and destroyed the Hong Kong Sanctum, allowing the Dark Dimension to bleed into the Material Universe.
However, Doctor Strange was able to reverse the destruction after brokering a deal with Dormammu, turning Kaecilius and the Zealots into Mindless Ones and restoring the Hong Kong Sanctum shortly afterward.
Trapped Between Dimensions
On a S.H.I.E.L.D. mission to rescue the supposed 'endangered' Eli Morrow, who was actually creating a machine powered by Quantum Batteries, a lethal amount of inter-dimensional energy was expelled throughout the Roxxon Power Plant. And this subsequently transported the nearby Leo Fitz, Phil Coulson and Robbie Reyes to a trans-dimensional state between the Material Universe and Hell, the dimension in which they were slowly being dragged further towards. During this time, these three men could see and hear everything that occurred in their universe and yet were unable to communicate and interact with anything.
Having figured out that Coulson, Fitz and Reyes were trapped, Aida, who had begun reading the Darkhold, began constructing an Inter-Dimensional Gate to rescue them. After some time, in which they, Reyes in particular, were being dragged to Hell, Aida finished the portal and brought them back into their universe.
Tear in Space-Time
After S.H.I.E.L.D. returned to their own time period, they discovered multiple Monoliths being stored in the Lighthouse. When the white, grey and black Monoliths were destroyed by an explosive Kree Orb, they created a rift to the Fear Dimension which leaked to Earth. This resulted in multiple illusions based on fears to appear and strange shifts in reality to change the atmosphere of the Lighthouse. The illusions created by the rift would haunt the agents of S.H.I.E.L.D.. The only way the rift could be closed or suppressed is with compressed Gravitonium, which was created with the help of Quake's abilities.
Approximately ninety years after the destruction of planet Earth, Deke Shaw claimed that Quake was the one who caused it. When she replied that she was not strong enough to cause such a disaster, Shaw explained a quantum physics theory that for every universe there are infinite parallel universes, implying that she came from the past into the future of an alternate universe and not her own. When the S.H.I.E.L.D. team returned to the past they prevented the destruction of Earth, altering the original chain of events and creating a different timeline.
This section requires expansion
- Earthly Plane: The universe where Earth is located, alongside the other Realms and a vast number of other planets and galaxies.
- Quantum Realm: The closest realm to the Material Universe, as it can and has been accessed by means of decreasing one's size to the extent they enter a different realm. Even though time and space behave differently in this realm, it's difficult to determine at which subatomic level does matter leave the Material Universe and enter the Quantum Realm.
- Astral Dimension: A parallel dimension in which the astral form of organisms exist purely detached from our physical bodies. In a simplified way, the Astral Dimension contains the 'soul' while the Material Universe merely contains the physical form of organisms. This dimension is incredibly close to the Material Universe, as some actions made toward the individual within the Earth Plane can have dramatic effects on their form within the Astral Dimension. This dimension is also a realm in which, according to Wakandan lore, the soul settles after death. For Black Panthers, it is where they can go to commune with their ancestors after ingesting the Heart-Shaped Herb.
- Mirror Dimension: An exact parallel dimension as to the Material Universe. It shows all movement and action that occur within the Material Universe, and yet no action within the Mirror Dimension can ever be witnessed nor will ever have an effect on the Material Universe. In this way, the Mirror Dimension is used as a battleground away from the Material Universe, in order to keep the public in safe. While it can be accessed though the use of the Sling Ring, both the Ancient One and Doctor Strange have demonstrated doing so without it 
- Dark Dimension: Dormammu, a large titan-like creature, asserts full control over his universe, and feeds off the planets and stars from the Material Universe. Unlike any other dimension, time doesn't exist in the same form that it does in all other universes. In other words, time has no effect in this dimension, hence all aspects of the Dark Dimension remain immortal, including Dormammu. Individuals have the capacity to draw minimal amounts of energy from the Dark Dimension, energy unique to that universe, in order to immortalize themselves. Yet in this way, it brings the entirety of the Dark Dimension, including Dormammu, closer to the Material Universe.
- Hell: A mysterious and mostly unknown dimension, with most of its characteristics and inhabitants left unrevealed. This universe is most likely a dark place, considering the transition between the Material Universe and Hell was depicted a lack of light. The only known inhabitant is the Spirit of Vengeance, and considering it doesn't want to return to Hell, this dimension must not be a desirable nor pleasant place.
- K'un-Lun Dimension: The mysterious mystical city of K'un-Lun is located in a different dimension, and can be accessed on Earth from a range of mountains in China.
- Fear Dimension: A dimension which manifests the fears of those exposed to it.
Travelling between universes through the Multiverse is incredibly difficult and usually requires a lot of energy. Yet several short cuts do exist. The Masters of the Mystic Arts use Sling Rings to travel between dimensions, as long as they can invoke a clear enough image in their minds as to where they want to go. However, it has been shown that some dimensions can be accessed without the use of the Sling Ring, but only by extremely powerful and knowledgeable people. Notable dimensions that have been accessed without the Sling Ring are the Quantum Realm, Darkforce Dimension, Astral Dimension, Mirror Dimension, K'un-Lun Dimension, and the Soulworld.
The Astral Dimension can be accessed by souls through Astral Projection; physical bodies cannot enter that dimension. Similarly, the Mirror Dimension can be accessed without using a Sling Ring; however, one needs a Sling Ring in order to get back to the Earth plane, otherwise they get stuck in the Mirror Dimension.
Others have also been able to travel between dimensions. Aida, with the help of the Darkhold, constructed an Inter-Dimensional Gate to free Phil Coulson, Leo Fitz and Robbie Reyes from being trapped between two dimensions. The Ghost Rider also developed the ability to open inter-dimensional portals between the Earthly Plane and Hell with his Hellfire Chain.
Behind the Scenes
- The Multiverse mentioned in Doctor Strange is referring to the collection of dimensions contained within Earth-199999. In the Marvel comics, the term Multiverse refers to the collection of all alternate universes, not simply dimensions within one universe.
- The possibility of parallel universes was teased in Doctor Strange by the Ancient One, who stated that the known universe was "one of an infinite number", and later by Karl Mordo when he warned Strange of the possible consequences of using the Time Stone. The multiverse theory itself was later explained in A Life Spent by Deke Shaw when he told Daisy Johnson, further alluding to the expanded Marvel multiverse as seen in the comics.
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Doctor Strange
- ↑ Agent Carter: 2.02: A View in the Dark
- ↑ Agent Carter: 2.08: The Edge of Mystery
- ↑ 4.0 4.1 Agent Carter: 2.10: Hollywood Ending
- ↑ Ant-Man
- ↑ 6.0 6.1 6.2 Agents of S.H.I.E.L.D.: 4.07: Deals With Our Devils
- ↑ Agents of S.H.I.E.L.D.: 5.12: The Real Deal
- ↑ Agents of S.H.I.E.L.D.: 5.13: Principia
- ↑ Agents of S.H.I.E.L.D.: 5.14: The Devil Complex
- ↑ Agents of S.H.I.E.L.D.: 5.03: A Life Spent
- ↑ Agents of S.H.I.E.L.D.: 5.22: The End
- ↑ Thor
- ↑ Ant-Man
- ↑ Black Panther
- ↑ The Man Behind “Iron Fist” Says “Danny Rand Is Not A White Savior”
- ↑ Avengers: Infinity War
- ↑ Agents of S.H.I.E.L.D.: 4.22: World's End
- ↑ Iron Fist: 1.01: Snow Gives Way
- ↑ Guardians of the Galaxy Vol. 2
- ↑ Guidebook to the Marvel Cinematic Universe - Thor: The Dark World
- ↑ Agents of S.H.I.E.L.D.: 5.12: The Real Deal