I believe Dumbledore made the statues in the ministry come to life to take the hit for him/block the hit. He didn't use any counter-curse or counter-jinx directly on the Avada Kedevra spell
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. ...
Not many people knew Sectumsempra - they'd need to know it exists to ban it.
Severus Snape invented Sectumsempra while at Hogwarts, and wrote it down in his Potions book. He doesn't seem to have told many people about it, it's possible he didn't tell anyone at all.
“Harry was about to put his book away again when he noticed the corner of a page folded ...
It isn't Unforgivable in the way that the Unforgivables are
A popular fan theory is that there is no grey area with Unforgivable curses. They do what they say on the tin and nothing else. Killing curse kills, imperio controls, crucio tortures. The caster also has to fully understand and mean to cause the effect the curse entails too. There's no excuse for ...
As @OghmaOsiris has said, spells can certainly be created, though the means of doing so is unclear.
There's also quite a simple example as early as the first book: Harry vanishes a pane of glass for a few minutes, allowing a snake to escape.
We can also postulate a process for spell creation from the sixth book: Harry sees several words before Sectumsempra,...
Using You-Know-Who's name breaks all protective enchantments and allows the speaker to be tracked.
‘You and Hermione have stopped saying You-Know-Who’s name!’
‘Oh, yeah. Well, it’s just a bad habit we’ve slipped into,’ said Harry. ‘But I haven’t got a problem calling him V—’
‘NO!’ roared Ron, causing Harry to jump into the hedge and Hermione (...
We find out later in the book, when Sirius writes to Harry after the task:
Congratulations on getting past the Horntail. Whoever put your name in that goblet shouldn’t be feeling too happy right now! I was going to suggest a Conjunctivitis Curse, as a dragon’s eyes are its weakest point — “That’s what Krum did!” Hermione whispered — but your way was ...
As long as you know exactly what you want, verbalizing the precise name isn't necessary (up to and incluing omitting the subject at all). Ref: GoF, Harry vs. dictionary; GoF, Mrs.Weasley vs WWW products
No line of sight needed. Ref: OotP, twins vs broomstics.
No need to know the location Ref: HP, Hermione vs Horcrux books.
No known distance limits (...
We don't know that the Dark Lord didn't use Priori Incantatem on the Elder Wand.
It would be a very logical course of action for the Dark Lord to use Priori Incantatem on the Elder Wand sometime after acquiring it. There is no explicit evidence that he did do this in the books, but his every small move isn't shown, so it's possible that he did and it wasn't ...
To the best of my knowledge, it's not truly unblockable. What has been said is that there is "no defense against it, no counter-curse" (By the fake Moody in book 4, during his lesson on Unforgiveable Curses). FakeMoody also says it can't be blocked, but please keep in mind that FakeMoody was a lying liar who tells lies, and things he says cannot ...
In the Half Blood Prince, Severus Snape created his own spell, Sectumsempra, which created invisible swords that cut the enemy.
Voldemort also created his own spells for his death eaters - the Dark Mark, for example: Morsmordre, as used in the 4th movie.
I imagine that wizards and witches at the level of competency as Voldemort and Dumbledore could come up ...
First let me say that I don't believe it is a real spell.
The thing we need to realize is that Ron did not know enough spells to differentiate between fake and real spells. Mr and Mrs Weasley would have used Nonverbal Spells at home.
We also know that Ron blindly trusted his brothers which is normal at that age.
“So we’ve just got to try ...
The use of the word "discovery" is used in another instance in the Harry Potter books:
CURRENTLY HEADMASTER OF HOGWARTS
Considered by many
the greatest wizard of modern times, Dumbledore is particularly famous
for his defeat of the Dark wizard Grindelwald in 1945, for the
discovery of the twelve uses of dragon’s blood, ...
Voldemort uses the killing curse several times in the Battle at the Ministry.
The first time Voldemort aimed it at Harry and Dumbledore animated
the golden wizard statue: "The spell merely glanced off its chest as
the statue flung out its arms, protecting Harry" (pg 813 of Scholastic
Next time: "Voldemort raised his wand and sent another jet ...
From the Order of the Phoenix:
Hatred rose in Harry such as he had never known before; he flung himself out from behind the fountain and bellowed, 'Crucio!'
Bellatrix screamed: the spell had knocked her off her feet, but she did not writhe and shriek with pain as Neville had – she was already back on her feet, breathless, no longer laughing. ...
No it does not trump the Fidelius Charm. As you point out, they are found at Tottenham Court Road because of the jinx on his name, they then travel to Grimmauld place and say his name again, and yet the Death Eaters stand
in the direction of the house that they cannot see."
Lupin all but confirms that they do not know that Harry is inside ...
TL;DR - the movies are incredibly unreliable.
The process of learning spells is far more drawn out and difficult than the movies indicate. Since the books more or less answer this question I won't do much but provide quotes. Here are some from the first few weeks Harry is at Hogwarts.
And then, once you had managed to find them, there were the classes
Harry wears his glasses during Quidditch because he cannot see without them. Why he cannot see without glasses, I think, has to be one of three reasons.
Harry's poor eyesight is collateral damage from Avada Kedavra, the darkest of evil curses. Body parts that are damaged, destroyed, or severed due to dark curses don't seem to be repairable in Potterverse:
Yes, the Banishing charm.
We see Harry, Ron, and Hermione practicing this spell in GoF:
They were supposed to be practicing the opposite of the Summoning Charm today — the Banishing Charm. Owing to the potential for nasty accidents when objects kept flying across the room, Professor Flitwick had given each student a stack of cushions on which to practice,...
The Ministry of Magic oversees the creation of all new spells.
Hermione is clear that the Ministry of Magic has a role in signing off new spells and checking they're safe. She was annoyed with the Half-Blood Prince because his spells didn't have this approval.
"So you just decided to try out an unknown, handwritten incantation and see what would happen?"
From Rowling’s old official site, jkrowling.com:
Members of the Order use their Patronuses to communicate with each other. They are the only wizards who know how to use their spirit guardians in this way and they have been taught to do so by Dumbledore (he invented this method of communication). The Patronus is an immensely efficient ...
Good question - ultimately one for the movie though, since, in the book, Ron wasn't trying to transfigure Scabbers, but rather, beetles into buttons.
Here is what we do know about Transfiguration and Ron and good vs broken wands:
Even in their first year Transfiguration class, Ron (and the rest of the class) are unable to successfully perform ...
He was not hit by the killing curse. He was accidentally hit by Sectumsempra, by Snape who was aiming for another Death Eater.
Now Harry was flying alongside Snape on a broomstick
through a clear dark night: he was accompanied by other hooded
Death Eaters, and ahead were Lupin and a Harry who was really
George ... a Death Eater moved ahead of Snape ...
I'd like to challenge one of the assumptions in the question:
... we can see many wizards in many really important situations/fights using very ineffective spells ...
Are they actually very ineffective? Not necessarily.
Most of the spells we see used in combat are actually effective at lowering or eliminating the combat ...
Based off this scene:
We know that the light does not travel from inside the cloak -> out, as Harry must hold the lamp outside of his cloak in order to see the books. If he held the lamp inside his cloak the light would only spread inside the cloak, and perhaps under his feet if there were some gaps. Since there is no light going out, it is safe to say that ...
I'm afraid the book implies just that - he learned it from Snape's whisper. I agree that it sounds a wee bit implausible... but that's what JKR's implying in CoS Chapter 11: "The Duelling Club":
Snape moved closer to Malfoy, bent down and whispered something in his ear. Malfoy smirked, too. Harry looked nervously up at Lockhart and said, 'Professor, could ...
After looking at the section in the book we know they were being stunned and falling down.
‘We’ll start with the Impediment Jinx, for ten minutes, then we can get out the cushions and try Stunning again.’
they laid out cushions all over the floor and started practising Stunning again. - Order of the Phoenix
and from year 4 we know Harry and crew ...
I don't think so.
After Harry learns what the third task will consist of (getting
through a maze) and then runs into Barty Crouch Sr and all that jazz,
the trio get in training.
For the next few days he spent all his free time either in the
library with Hermione and Ron, looking up hexes, or else in empty
classrooms, which they sneaked into to ...
There are two factors that led to Voldemort's defeat. One is, as you've noted, his failure to master the Elder Wand. But the other is the failure of all of his spells after he cast Avada Kedavra on Harry.
Because Harry died to save his friends, he and they received the same kind of magical protection that Harry bore after his mother died to save him. The ...
Avada Kedavra is said to be unblockable in Goblet of Fire
Moody raised his wand, and Harry felt a sudden thrill of foreboding.
‘Avada Kedavra!’ Moody roared.
There was a flash of blinding green light and a rushing sound, as though a vast, invisible something was soaring through the air – instantaneously the spider rolled over onto its back, unmarked, ...
If you're a Star Wars aficionado, think about Confundus as a light Force suggestion (sometimes used by Luke in the EU, at the level - or even less so - of Ben Kenobi's "These are not the droids you are looking for").
While it can theoretically be used to influence other person's actions, it's an indirect influence: you let them believe something they ...