Marvel is the top publisher in the comic industry, telling some amazing stories over the years. The heroes and villains of the Marvel Universe are icons and the trials and tribulations of their lives have captured fans' imaginations for decades. As great as those stories have been, sometimes a change of pace is needed and that's where alternate universe storylines come from.
Marvel's What If... told some great stories over the years, with alternate universe stories eventually bleeding into the main line of comics. Some of these stories eventually made their way into Marvel's canon, becoming real parts of the fictional universe.
10 The World Of Heroes Reborn Became An Actual Alternate Universe
Heroes Reborn was a Hail Mary pass attempt by Marvel to save the Avengers and Fantastic Four by letting former Marvel artists Jim Lee and Rob Liefeld take over their titles, the stories of which would take place in a world created by Franklin Richards, one of the most powerful beings in the Marvel Universe.
It was revealed that entire world took place inside a ball that Franklin carried with him and when the story was over, the whole thing disappeared. However, it would be brought back as an actual alternate universe a few years later, making that world part of the Marvel Multiverse.
9 Rick Jones Did Become The Hulk For A Short Period Of Time Like He Did In An Early Issue Of What If...
What If... debuted a lot of great alternate universe stories and one of those came in What If... #12, Vol. 1. This story put a spotlight on perennial Marvel sidekick Rick Jones and posited that instead of Bruce Banner, he became the Hulk. While there have been many versions of the Hulk, this one was pretty different from Banner and it was a good story.
For a brief period in the main Marvel Universe, Rick Jones did become the Hulk and later would end up as A-Bomb, a heroic version of the Abomination that helped Hulk in the fight against the Red Hulk.
8 House Of X/Powers Of X Made The Machine-Ruled Dystopia Of Days Of Future Past Inevitable
Days Of Future Past is a classic X-Men story, involving Kate Pryde being sent from a Sentinel conquered future to the present to prevent the assassination of Senator Robert Kelly. While this stopped that future from happening in the main timeline, it still existed as alternate timeline. House Of X/Powers Of X revealed a chilling fact, which was that the Sentinel-ruled future is inevitable.
Moira MacTaggert was revealed to be a mutant, one who restarted her life every time she died. She witnessed nine timelines and mutants lost in everyone of them. The canon future of the Marvel Universe is one where machines have taken over and killed all of the heroes and mutants and nothing can stop that.
7 What If... Fallen Son Posited What Would Have Happened If Cap Survived Civil War & Iron Man Hadn't, Which Happened After Civil War II
What If... Fallen Son had a rather interesting premise, one that changed everything. Instead of Cap being killed after Civil War, Iron Man was and the world was vastly different. While this story wouldn't be made exactly canon, a similar thing would happen in Civil War II, one of Marvel's most maligned events of the last twenty years.
Iron Man would be defeated by Captain Marvel in this story and was basically brain dead, except for a interactive hologram that Riri Williams had. Captain America was a member of Hydra at the time, so he took advantage of Iron Man's "death" to further his goals.
6 Jane Foster Got Her First Chance As Thor In What If...
The Jane Foster version of Thor was more beloved than her detractors want everyone to think, with her book selling more than the previous one starring Thor Odinson. It wasn't the first time she got a chance to be Thor, as that was in What If... #10, Vol 1. While it played out differently than it did in canon, with Jane finding Mjolnir instead of Donald Blake, it was still the first time she held the hammer.
Jane Foster as Thor would change the way the character was seen by fans. She became more popular than ever before and while the What If... issue played the whole thing as impossible, Jane as Thor has become a great part of Thor canon.
5 There Were Two Issues Of What If... About Conan In The Present Day, Which Would Happen In The Savage Avengers
Marvel has been publishing Conan the Barbarian comics since 1970. For reference, that's longer than Wolverine or Punisher have existed. He had a few crossovers with Marvel characters but stayed in his own Hyborean Age. His books were popular, though, and he starred in two different What If... issues about him in the present.
Both of these would see him bringing his brutality to the present day, even becoming a crime lord in one of them. In recent years, Conan would actually come into the present, joining the roster of the team book The Savage Avengers.
4 The World Of Mutant X Became A Part Of The Marvel Universe When Bloodstorm Joined X-Men: Blue
Mutant X was a different kind of '90s mutant book. Havok was shunted into an alternate universe, one where events had went quite differently for the world. He led the premiere mutant team, known as the Six. One of the members of the team was Bloodstorm, a version of Storm who was a vampire.
Once the book ended, the alternate world disappeared until Bloodstorm was brought into the regular Marvel Universe to join the time lost original five X-Men in X-Men: Blue. She would start a relationship with Cyclops but was killed by Ahab in X-Men: Extermination.
3 What If.... #5 (Vol. 1) Had A Whole Slew Of Future Captain America Plotlines In Its Pages
What If... #5 (Vol. 1) posited what would have happened if Captain America had never been frozen but it actually contained a lot of things that would happen in the future. Cap and Bucky were able to defuse the bomb plane, so Bucky survived and the two would continue fighting, with Cap eventually becoming Director of S.H.I.E.L.D. and Bucky taking over as Captain America.
While it all happened in different ways, all of these plotlines did occur in Cap's book. Bucky was revealed to have survived, he would become Captain America eventually, and Captain America was put in charge of S.H.I.E.L.D.
2 The World Of Old Man Logan Has Grown Immensely Since The End Of The Story
Old Man Logan is a beloved Wolverine comic that saw a pacifist Logan and Hawkeye traveling a villain conquered United States on one last mission in the future. The story struck a chord with fans but was seemingly a one off, until the world was revealed to be a part of the Battleworld in 2015's Secret Wars.
At the end of Secret Wars, Old Man Logan would become a part of the main Marvel Universe before returning to his own world and dying. Since then, there would also be Old Man Hawkeye, Old Man Quill, and Avengers of the Wastelands books, all adding to the lore of the original story.
1 The Age Of Apocalypse Was Brought Back For Its Tenth Anniversary & Made Into An Extant Alternate World
The Age Of Apocalypse is probably the most beloved alternate universe story Marvel ever put out. Taking place in a dystopian world where Professor X was killed before forming the X-Men and Apocalypse took over America, it supplanted the X-Men books for months in 1995, at the height of their sales power.
The story would end with the destruction of the world in X-Men: Omega but was brought back in The Age Of Apocalypse, a six issue miniseries published for the story's tenth anniversary. Since then, it would be considered a vital alternate Earth, sometimes crossing over with the main one.