How can Dumbledore block avada kedavra and why was Snape’s colored blue instead of green?

The Avada Kedavra – the killing curse from the Harry Potter Wizarding World is unforgivable, cannot be blocked, and is colored green. Every time books or movies make mention of the spell, they insist on those things. Why is it always like that?

Going through the books and the movies, we find several instances where Avada Kedavra was blocked and one where it was not green but blue. Examining these occurrences, the fans, of course, have several theories, and we will present them.

How does it miss or get blocked?

The readers are first explained the details about the Avada Kedavra curse in the Goblet of Fire when Barty Crouch Jr., disguised as Alastor Moody, explains to the class how unforgivable curses work. When teaching about the killing curse, he clearly states that there are no ways to block it.

Crouch, in fact, only points out that no magical barriers or blocks can prevent the curse from getting through to its target. It goes for counter spells, simply put, magic cannot block it directly.

But, in reality, there are a number of ways for this. For instance, if a large enough object is between the wand casting Avada Kedavra and its target, which is how Dumbledore does it.

It primarily concerns the battle between Dumbledore and Voldemort at the Ministry of Magic in the fifth book: “Harry Potter and The Order of the Phoenix” While it was not in the movie, the fight is a bit richer in the books, and here is an excerpt:

“But the headless golden statue of the wizard in the fountain had sprung alive, leaping from its plinth to land with a crash on the floor between Harry and Voldemort. The spell merely glanced off its chest as the statue flung out its arms to protect Harry.

“What -?” cried Voldemort, staring around. And then, he breathed, “Dumbledore!”

(Skipping to a later part of the duel)

“Voldemort raised his wand and sent another jet of green light at Dumbledore, who turned and was gone in a whirling of his cloak…”

(Skipping a bit more)

“Voldemort sent another Killing Curse at Dumbledore but missed…”

(A bit more)

“Another jet of green light flew from behind the silver shield. This time it was an one-armed centaur, galloping in front of Dumbledore, that took the blast…”

Taken from the book Harry Potter and the Order of the Phoenix by JK. Rowling

All these different excerpts are from that single encounter in the ministry. The first time Voldemort’s Avada Kedavra was blocked was when he targeted Harry, and Dumbledore moved a golden statue nearby in its path.

Voldemort targeted the other three curses directly at Dumbledore. Dumbledore dodged the first, while the second one missed on its own. He used magic to animate a statue again for the fourth one, where a centaur statue blocked the path of the curse.

So, we see that not only that Avada Kedavra can be blocked and dodged, but there is a number of ways to do it for a creative witch or wizard.

Why is it not always green?

The second distinct trait of the Avada Kedavra spell is that it is green in almost every iteration shown in the books and the movies. However, nobody ever said it is a rule. It is where the movies go a little further than the books.

We are referring to the emotional and devastating scene in the sixth installment Harry Potter and the Half-Blood Prince, where Snape kills Dumbledore with Avada Kedavra. It is one of the most devastating scenes in the entire series, owing to a brilliant portrayal of Severus Snape by the late Alan Rickman.

It is clear to every fan that the two had an agreement where they were to trick the Dark Lord. But, one detail in the movie is perhaps not that clear, although it has produced a lot of fan questions and theories. That detail is the color of Snape’s killing curse.

Snape’s blue Avada Kedavra

“If you don’t mind dying,” said Snape roughly, “why not let Draco do it?”

“That boy’s soul is not yet so damaged,” said Dumbledore. “I would not have it ripped apart on my account.”

An excerpt from the book Harry Potter and the Half-Blood Prince by JK. Rowling

Dumbledore and Snape had a plan where Snape would again infiltrate Voldemort’s inner circle, and for that, he had to prove his loyalty.

But it is also important that Dumbledore has taken Snape in after he deflected from the Death Eaters the first time and has vouched for him numerous times. If not for Dumbledore, Snape would have likely rotted in Azkaban or would at least have fewer options for a life after that, let alone to teach at Hogwarts.

In simple words, Snape owed everything to Dumbledore, and he was his only true friend throughout the past two decades. The only one who really knew him. So, naturally, Snape was hesitant to commit the deed, even if Dumbledore begged him at the end to do it.

“You’ve got to mean it, Harry”

Voldemort said it best when he tried to talk Harry into using Avada Kedavra to kill Bellatrix. The intent of the caster is a vital component of the spell. While Snape was still able to produce Avada Kedavra without any intent to kill, being a great wizard, the mix of hesitation and necessity probably resulted in the spell being blue.