Often, it starts with some sort of magical accident or a powerful spell gone wrong. Maybe a spell that was supposed to transport Harry to a different part of the wizarding world misfires and sends him to Camelot instead.
Some fanfictions might begin with a prophecy. A seer in the wizarding world predicts that Harry must go to Camelot for some great purpose. So, he sets off on a journey, not really knowing what to expect in this strange new world. Or perhaps there is a disturbance in the magical fabric that connects different magical realms, and Harry, being the hero he is, is drawn towards Camelot to fix it.
Merlin would first have to explain the fundamental differences. In Camelot, magic seems to be more of an inborn gift that is often tied to destiny, while at Hogwarts, magic can be learned by anyone with the aptitude. Harry would need to adjust his mindset. He'd observe how Merlin uses magic without a wand, perhaps by just using his hands or his willpower. Harry might try to combine his Hogwarts - taught magic with Camelot's magic. For instance, he could use a protection spell he learned at Hogwarts while also tapping into Camelot's natural magic sources for added strength.
Perhaps at a big gathering in the Great Hall. After all the chaos and battles, everyone is eager to hear his story. Harry stands up on the dais where the teachers usually sit and starts from the very beginning, about how he grew up not knowing he was a wizard, living with the Dursleys. He tells of the strange things that used to happen to him that he didn't understand at the time.
Harry is the central figure. In addition to the well - known Camelot characters like Arthur and Merlin, Guinevere can also be a main character in some fanfictions. She could play a role in Harry's integration into Camelot society. There might also be some original characters created by the fanfiction author, like a young apprentice in Camelot who becomes Harry's friend and helps him understand the ways of Camelot. Another often - seen character is Morgan le Fay. She could be an antagonist to Harry, seeing his presence as a disruption to her plans in Camelot.
Well, usually it changes the relationships. For example, his friendship with Ron and Hermione might be strained at first. Since they are in different houses. Harry might also face different types of rivalries within Slytherin. He has to prove himself to his new housemates.
Typically, it changes the relationships. Instead of being close with Gryffindors like Ron and Hermione, he forms new bonds with Ravenclaw students. His focus may shift from Gryffindor - like bravery to Ravenclaw - centered intelligence. For example, he might spend more time in the library.
In a 'Harry Potter raised pureblood' fanfiction, the story often changes in terms of Harry's magical education. He might receive a more traditional pureblood education, which could include learning ancient spells and magic that were lost in the mainstream wizarding world. This gives him an edge and changes the power dynamics in his battles against Voldemort. For example, he could use some pureblood - only defensive magic that Voldemort isn't expecting.
He might give Harry detention. Harry could be made to clean the trophies in the trophy room or help Hagrid with some difficult tasks in the Forbidden Forest under strict supervision.
They could have an adventure where they help Camelot defend against a dark sorcerer. Harry's combat magic from Hogwarts would be useful, and Merlin's knowledge of Camelot's magic and its secrets would be crucial. Another adventure might be to find a lost magical artifact that is important for both Camelot and the wizarding world. Along the way, they might encounter magical creatures unique to Camelot that Harry has never seen before, like the Questing Beast.
Well, in many Harry Potter fanfictions about 'Changing Fate', it often involves a character having some sort of foreknowledge. For example, if a character knows how the original story ends, they might try to change things. It could be Harry himself getting a chance to redo parts of his life and make different choices. Maybe he decides not to go to the Forbidden Forest in a certain situation, which then has a ripple effect on other events.
Often, it starts with Harry's decision to become a doctor. Maybe he realizes that there are so many people, both Muggles and wizards, in need of help. Then, he begins his studies. If it's in the wizarding world, his studies might include both magical and non - magical medical knowledge.