One interesting concept is the idea of different physical laws. For example, in some alternate universe fictions, gravity might work in reverse. Another is the concept of alternate versions of ourselves. We could be heroes or villains in another universe. Also, the technology can be radically different, like telepathy being a common form of communication instead of using phones.
In alternate universe science fiction, the concept of parallel evolution is fascinating. Species might have evolved in completely different ways. For instance, instead of mammals becoming the dominant species on Earth - like planet in an alternate universe, it could be reptiles or insects. The concept of different forms of energy is also cool. There could be a universe where magic is just another form of energy, and beings have learned to manipulate it just like we do with electricity.
Well, time can be really different in alternate universe science fiction. It might move at different speeds or even be non - linear. And the social structures can vary greatly. There could be matriarchal societies instead of patriarchal ones. Creatures that are extinct in our world might thrive in an alternate universe. It's all about exploring the 'what ifs' of different universes.
Some fanfictions in the Avengers alternate universe explore the idea of the Avengers being part of a post - apocalyptic world. In this setting, they might have to fight against new and more dangerous threats that emerged from the ruins. Maybe there are mutated creatures or a new breed of supervillains. Also, an alternate universe could feature a younger version of the Avengers, like teen versions, and their journey of growing into heroes while dealing with the typical teenage problems along with the super - hero stuff.
One interesting concept is the idea of meeting alternate versions of oneself. It can lead to self - discovery and exploring different personalities. Another is the discovery of unique cultures and societies in the alternate universes. For example, a world where magic is the norm instead of science. And then there's the concept of changing the course of events in an alternate universe, which can have far - reaching consequences.
One interesting concept could be a Naruto AU where the main characters have different elemental affinities. For example, Naruto might be a water - type user instead of wind. Another concept could be a world where the Akatsuki are the heroes. They could be fighting against an oppressive regime that the Hidden Villages support. Also, a fanfic could explore a Naruto AU where the tailed beasts are free and coexist peacefully with humans from the start.
One interesting concept could be if the characters had different careers. For example, instead of being in a glee club, they could be professional dancers in a big city dance troupe. Another concept might be a world where the glee club is a secret society with special powers related to music.
In RWBY alternate universe fanfiction, a cool idea is that the characters switch roles. Yang could be the shy, bookish type while Weiss is the brash, party - loving one. Also, the Dust element could be completely different. Instead of being a resource mined from the earth, it could be something that is created through magic. Additionally, an interesting concept is an AU where the characters are in a modern, non - combat setting, like a high school drama where they still have their unique personalities but deal with normal teenage problems.
One interesting concept could be a Naruto AU where the ninja world is a modern, high - tech society. Instead of using traditional ninja tools, they use advanced weapons and gadgets. Another could be an AU where the main characters have different elemental affinities than in the original story, which would change their combat styles and relationships.
One interesting concept is the re - imagining of characters. For example, in an alternate universe, a classic hero could be a villain. Another concept is the different power structures. Maybe magic is used in a completely new way, like being a currency instead of a weapon. Also, the alternate social hierarchies can be fascinating. A race that was once oppressed could be the ruling class.
Well, in Star Wars alternate universe fanfic, a cool concept is the existence of Force - sensitive species that were never mentioned in the original canon. Maybe there's a species that can manipulate the Force in ways that are completely different from Jedi or Sith, like being able to use it to communicate with all forms of life on a planet simultaneously. Another interesting thing could be a story where the Galactic Empire never fell, but instead evolved into a more benevolent regime over time due to some internal reforms. And then there are fanfics that explore what would happen if a character like Han Solo was a Jedi from the start, which would change a whole lot of the storylines we know.
One interesting concept could be a universe where Tony Stark is a sorcerer instead of a tech genius. He could use magic in ways similar to how he manipulates technology in the main universe. Another concept might be a world where he's a pirate, sailing the high seas with high - tech ships and weapons of his own creation. Also, an alternate universe could have Tony as a teacher, passing on his knowledge of science and innovation to the next generation.
One interesting concept could be a world where Voldemort won the war. In this alternate universe, Hogwarts might be a very different place, with dark magic being taught openly. Another concept could be a universe where the houses are not divided as they are in the original. Maybe students are grouped based on different criteria like magical talents other than just bravery, intelligence, etc. For example, there could be a group for those who are good at magical creatures handling.