Harry Potter and the Deathly Hallows Part 2 is the shortest film in the Harry Potter series, and yet contains the most important sequence in the history of the franchise: The Battle of Hogwarts.
The fight is the culmination of every emotion and tragedy felt by Harry over seven years of turmoil, and his experiences with friends and enemies alike encompass the meaning of love and protection in one giant culmination of violence.
Of course, a film simply does not have the time to dedicate to each character and scene to convey its message as clearly as an 800 page book does. But some of the changes made to the Battle of Hogwarts are some of the most frustrating changes across any of the films in the series, including very unnecessary changes when it comes to the depiction of major character deaths and stupid decisions made by Harry even after the battle has ended.
Essentially every spoiler possible ahead for both the Harry Potter and the Deathly Hallows film and book.
12. The Final Fight Between Harry And Voldemort
Perhaps the biggest change of all, the final fight between Harry and Voldemort plays out pretty differently on the screen compared to the book.
In the movie, Harry and Voldemort stand on opposite ends of a ruined courtyard. They are completely alone as their wands connect in Priori Incantatem, without a single onlooker in sight. The symbolism is to emphasise their loneliness in their prophecy: neither can live while the other survives. At the end of the day, it always came down to a lone battle between the foes, regardless of the help each received along the way.
The book, however, goes for a different type of symbolism. Here they battle in the centre of the Great Hall, enclosed in a circle of every survivor of the battle as they watch Harry jeer at Voldemort, who he refuses to call anything but "Tom". Harry triumphantly explains to Voldemort how he'll win the battle, going into the detail about the series of events that led to him being the master of the Elder Wand - a highly significant player in the final book that takes a backseat in the film.
When Voldemort dies in the film, the reasons behind his death aren't truly explained, as the two fight in silence and Voldemort sinks to the ground and disappears in a cloud of ash. In the book, Voldemort's killing curse very clearly rebounds due to the power of the Elder Wand, and a dead body is left behind on the floor as Harry's friends mob him in victory.
There are pictures from the set of Deathly Hallows Part 2 that show Harry examining Voldemort's dead body as opposed to the ash ending, but this version of the fight was ultimately not used, despite its importance as it expressed that Voldemort was never as untouchable as he thought and ultimately dies as any other human being would.