A common trope is the 'alternate universe' idea. In these fanfictions, the wizarding world could have a completely different social structure or history. For instance, if the Death Eaters had won the war before Harry started at Hogwarts. Also, the 'romantic pairings different from the canon' trope is popular. Fans like to explore relationships like Hermione with Draco or Harry with Luna that are not the main focus in the original books.
Some fanfictions use the 'teacher - student relationship expansion' trope. This could be exploring more about a particular teacher's influence on Harry outside of the classroom. For example, how Lupin could have mentored Harry more deeply in magic that was not taught at Hogwarts. Another trope is the 'muggle - born discovery' trope, where muggle - borns find out about the wizarding world in different and more complex ways than in the original story.
One common trope is the 'alternate universe' where things are drastically different from the original series, like if Voldemort won the war. Another is the 'character redemption' trope, for example, Draco Malfoy getting a chance to be a good guy in a different way. And there's also the 'romantic pairings' trope, like Hermione ending up with someone other than Ron in some fanfictions.
One popular trope is the 'alternate universe' where the story takes place in a different setting or with different rules from the original series. For example, a world where Voldemort won. Another is the 'character rewrite' where a character's personality or backstory is changed. And the 'romantic pairing' trope, like Hermione with Draco, which explores relationships that weren't in the original books.
A common trope is power - related. In Harry Potter and Marvel fanfiction, you often see characters either sharing or comparing their powers. For instance, how would Captain America's physical abilities stack up against a wizard's magical skills? Also, the 'found family' trope is there. Characters from both universes coming together to form a new family unit, like some Avengers joining forces with the Hogwarts crew.
One popular trope is the 'crossover' where characters from Charmed and Harry Potter universes interact. For example, the Halliwell sisters might meet Harry, Hermione and Ron. Another is the 'power transfer' trope, like a Charmed one getting some magical ability from the Harry Potter world or vice versa. And the 'hidden relation' trope is also seen, such as a character from one universe being related to a character in the other in some unexpected way.
One popular trope is the 'enemies - to - lovers' where characters who initially dislike each other, like Draco and Hermione, fall in love. Another is the 'forbidden love' trope, for example, a love between a Muggle - born and a pure - blood in a world with so many class differences in the wizarding world. And of course, there's the 'soulmate' trope where two characters are fated to be together.
One popular trope is the 'alternate universe' where the story takes place in a different setting than the original books. For example, a modern muggle world with a hidden wizarding society. Another is the 'time - travel' trope, which allows characters to go back in time and change events. And the 'found family' trope is also common, where characters form deep bonds outside of their biological families.
One popular trope is the 'coming - out' story. This could involve a character like Harry Potter himself realizing and coming to terms with his bisexuality. It often includes the character's internal struggle, as well as how their friends and the wizarding world around them react.
One popular trope is the 'fish out of water' situation where the main character, often a self - insert or an OC, finds themselves in the middle of a harem of Harry Potter characters. Another is the 'enemies to lovers' within the harem, where some of the characters initially dislike the main character but then fall for them. Also, the 'power - up' trope is common, where the main character gains new magical abilities or knowledge through their interactions with the harem members.
There are several popular tropes. The 'hidden past' trope, where the professor has a secret past that the student gradually uncovers. It adds an element of mystery. Also, the 'life - changing advice' trope, in which the professor gives the student advice that completely alters their path. And don't forget the 'teacher - turned - protector' trope, which often comes into play when the student is in danger.
One popular trope is the 'Chosen One's Harem'. Since Harry is the Chosen One in the Potterverse, having a harem around him can play on the idea of different characters being drawn to his power and destiny. Another is the 'School Harem' as Hogwarts is a central setting. Girls (or guys in some fics) from different houses might form a harem around Harry due to his heroics in school. Also, the 'Magical Bond Harem' where magical bonds, like a soul - mate type of bond, connect Harry to multiple characters in the harem.