A great idea for Rick and Morty fan fiction could be a story set in a post - apocalyptic version of their universe. Rick and Morty are the only survivors in their dimension and they have to use Rick's intelligence and Morty's unexpected courage to rebuild society. They could encounter other versions of themselves from different timelines who either help or hinder their progress. This would allow for a lot of character development and exploration of the relationship between Rick and Morty in a very different context.
One idea could be exploring an alternate universe where Rick is a good guy and helps different planets instead of causing chaos. Another could be a story where Morty discovers he has a hidden power that even Rick doesn't know about. Maybe a fan fiction about Rick and Morty getting stuck in a time loop and how they try to break out of it.
One idea could be to explore an alternate universe where Rick and Morty switch personalities. It would be really funny to see Morty being the super - intelligent, jaded scientist and Rick being the naive and easily - frightened sidekick for a change.
One idea could be to explore an alternate universe where Rick and Morty swap personalities. Morty becomes the super - intelligent, reckless one, while Rick is more timid and hesitant. Another could be a story where they get stuck in a time - loop within a particularly strange dimension and have to figure out how to break free. Maybe a fan fiction where they encounter a version of themselves from the future who have become the rulers of the multiverse.
One idea could be a fanfic where Rick and Morty get stuck in a dimension where time runs backwards. Another could be about Morty becoming a super - intelligent scientist like Rick for a day. Maybe a fanfic where they meet alternate versions of themselves who are complete opposites in terms of personality.
One idea could be Summer going on an adventure with Rick to a parallel dimension where all the rules of time are reversed. She could struggle to adapt at first but then use her wits to survive. Another could be Summer getting involved in one of Rick's crazy experiments that accidentally gives her a unique superpower. She then has to figure out how to control it while dealing with the chaos it causes in the family.
One idea could be creating an OC who is a super - intelligent alien from a dimension where time moves backwards. This OC could interact with Rick and Morty in a way that challenges their understanding of the multiverse. Another idea is an OC that is a half - human, half - robot created by Rick's nemesis. The OC could be on a mission to destroy Rick but ends up befriending Morty instead. A third idea is an OC that is a magical being from a dimension full of fantasy creatures and they bring a new kind of chaos to Rick and Morty's adventures.
One idea could be an OC who is a brilliant scientist from another dimension, but with a very different moral code than Rick. They could start as an adversary but then form an unlikely alliance. For example, this OC might believe in using science for the greater good of their own dimension in a way that Rick would find naive.
A cool Rick and Morty crossover fanfiction idea is with 'Back to the Future'. Marty McFly could end up in Rick's dimension and they could team up to fix some time - space continuum issues that Rick's inventions caused. Or a crossover with 'The Simpsons'. Homer could be awed by Rick's intelligence and Morty could make friends with Bart. Also, a crossover with 'Star Trek' would be amazing. The crew of the Enterprise might be both intrigued and horrified by Rick's unethical scientific experiments.
One idea could be Naruto characters getting access to Rick's portal gun and exploring different dimensions in the Rick and Morty universe. They might encounter strange creatures and have to use their ninja skills to survive.
In a genderbend fanfiction, perhaps female Rick and female Morty stumble upon a planet where gender roles are completely reversed from what they're used to. This leads to a series of comical and thought - provoking situations. For example, they might find that on this planet, women are the ones who are always on adventures and men stay at home. This could make them reevaluate their own relationship and the roles they play in their adventures.
One idea could be that Fem Morty discovers a new dimension with Grandpa Rick that has a society ruled by female scientists. They have to navigate the strange social norms and power dynamics there.