In Harry Potter, we can see many wizards in many really important situations/fights using very ineffective spells, and so later on they pay the price for that (e.g. somebody uses expelliarmus, but later on he loses to somebody else or even gets killed by the same person he could have killed first).

For example, in the Harry Potter and the Order of the Phoenix, Harry used Expelliarmus on Lucius Malfoy, even though he had two magic wands at the time (he lost the second as well few seconds later, but it doesn't matter now), so he was able to keep fighting even though he could have been put out of the fight, using e.g. Stupefy. Then, after Sirius gets killed by Bellatrix, Harry goes after her and uses crucio - one of the three Unforgivable Curses, same as the Avada Kedavra, and he could have gotten rid of one of the most important of Voldemort's servants.

Is it due to it being hard to cast such a powerful spell, and they are afraid they would fail the spell in such a serious situation, or don't they want to hurt somebody?

Why would one prefer Expelliarmus, while Stupefy is more powerful/effective in the most cases? There are also many other spells, which are very poorly used in the fights (I don't mean unforgivables), but would put enemy out of fight more effectively than Expelliarmus.

As few people found this question duplicate, I would like to explain why did I ask another question about this topic. In this question author explicitly asked about why don't Death Eaters always use Avada Kedavra - which is obvious to me. I'm asking why wizards generally don't use more powerful spells during the fight, not necessarily the Avada Kedavra spell to kill enemy.

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    Related: Why don't Death Eaters always use Avada Kedavra?. Basically the good guys don't use Unforgivable Curses (most of the time) and the Death Eaters mainly fight kids. As for people using less "efficient" spells - signature moves and habit. It works the same (although it shouldn't, granted) in real-life fights.
    – Jenayah
    Commented Dec 28, 2018 at 10:07
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    Note that for example police, although armed with guns, prefer other means of stopping criminals (in most westernised countries). But I can see your point.
    – 11684
    Commented Dec 28, 2018 at 15:34
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    I'm tempted to edit the title to "Why aren't wizards all homicidal maniacs?" but I guess that wouldn't be appropriate. :-) Anyways, I observe that all the examples in your question are about Harry; you should note that he's the hero of the story, which (in this sort of book) seriously constrains what actions the author can allow him to take. (Also, Expelliarmus is his specialty, the spell he's best at.) Your question might be improved with a wider variety of examples. Commented Dec 28, 2018 at 22:09
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    It's not canon, but I got the distinct impression from the books that most wizards had absolutely no clue about magic. Halfbloods, like Snape, seem to grasp it's principles better than the "pureblood" families. Information is hoarded and taught only to favored disciples, so education is crippled - for example the official potions textbook is only sufficiently correct to sometimes kind of work. It's when Harry gets hold of the annotated copy in "Half Blood Prince" that he becomes successful in potions.
    – pojo-guy
    Commented Dec 29, 2018 at 4:07
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    I'd like to know this, too, and sadly the answers I see so far focus too much on the unforgivables rather than the more-interesting choice between curses like expelliarmus and stupefy, where the latter is almost always more effective, and we never see it fail if it connects. With this in mind, I suggest un-accepting the answer (and resisting pressure to accept an answer at all) until you have a good answer that actually addresses this more-subtle question. Commented Dec 29, 2018 at 20:44

8 Answers 8


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 ...

emphasis mine

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 effectiveness of the opposing wizard or witch. The other answers have covered in great depth why they aren't followed by a coup de grâce, I'll only be focusing on getting the opponent into a situation where that would be possible.

Spell Selection

While combat isn't exactly the focus of the Harry Potter books, there's quite an extensive list of offensive and defensive spells listed on the internet. For the sake of brevity, I'll be using the "least powerful" spells listed here, omitting those we don't actually see used in combat. For example, the curse of the bogies is out because we only ever see it cast by Peeves as a prank, but Densaugeo is in because it was cast in combat (for some value of combat) by Draco Malfoy - also: it's an excellent example of the silly sort of spell that's surprisingly relevant to wizarding combat.

Common Themes

The effectiveness of many of these spells hinge on these facts of life for a witch or wizard:

  • Pronunciation matters, so if you can make talking difficult, spellcasting becomes difficult.

  • While most of the named cast seem eventually seem proficient in non-verbal casting, the text describes it as difficult (or at least requiring concentration) and there seems to be a decrease in effectiveness, so preventing verbal casting does provide a significant combat advantage.

  • Removing the wand from a wizard or witch essentially eliminates their combat effectiveness. The ability to cast wandless magic is rare for European witches and wizards, and is chancy and less powerful even for those who posses the ability to do without a wand.

The Spells

Densaugeo makes your teeth to elongate to an absurd degree. As anyone who's had braces or a retainer can attest, anything extra in your mouth absolutely messes up your pronunciation until you've had a chance to get used to the addition, which can take a few days. Time you would not have in a combat situation.

The finger removing jinx does exactly what it's name would imply, and good luck holding onto a wand well enough to swish and flick without fingers.

Full-body bind is combat gold: they can't move their wand and their perception is limited to straight ahead. While most don't follow this up with a cutting curse to liberate their opponent's head from the tyranny of being attached to their body, for reasons amply covered in other answers, the potential to do so is very much there.

Incarcerous should be more respected than it is. In addition to immobilizing an opponent it also gags them and, as noted above, this does really bad things to the combat effectiveness of a wizard or witch.

If the Jelly-brain Jinx is actually the one that hit Ron in the Department of Mysteries, we have a pretty good example of why it would be effective in combat: Ron immediately did something extremely stupid, taking himself out of the fight and resulting in permanent scarring.

The Jelly-legs Curse, Locomotor Mortis and Tarantallegra are all effective for the same reasons: they significantly reduce mobility, and good luck trying to aim when your legs aren't cooperating.

The Leek jinx isn't actually that effective, until you remember that having leeks growing out your ears is going to seriously compromise your hearing, making countering incoming spells much more difficult. This is a neat advantage if the caster hasn't gotten the hang of non-verbal spells.

The Pimple Jinx is, based on Goyle's reaction, distractingly painful. When combined with the Jelly-Legs curse, it sprouts tentacles which obscure the target's vision. Either of these would create an opening for a more damaging spell that might otherwise be difficult to land. In the same category, though presumably less painful, is the tickling charm Rictusempra.

Langlock glues the target's tongue to the roof of their mouth, seriously hampering spellcasting.


Even the silly-sounding spells are enough to disable or severely reduce a witch or wizard's ability to continue combat, so it shouldn't be a surprise that these would be the ones most commonly used.

Even Death Eaters need to practice, so if there's a spell that's equally effective at creating a situation in which you could kill your opponent and won't accidentally kill your sparring partner, it's going to see considerably more use than a more dangerous spell which is harder to practice safely. Humans are very much creatures of habit and the ability to do magic doesn't seem to change that, so what's used in practice is what'll be used in an actual fight.

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    Also the only extensive answer that doesn't hyper-focus on the unforgivable spells as the only effective spells.
    – Ellesedil
    Commented Dec 28, 2018 at 19:50
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    I love this answer. Having an unpredictable, preemptive bag of tricks lends to greater dueling versatility than say, a signature move.
    – OhBeWise
    Commented Dec 28, 2018 at 20:34
  • @Ellesedil The question post does focus (in explanation at least) on killing hence the focus on unforgivables but I do think this answer is a good one - more inclusive than mine and deserves more upvotes than the one I can give. Commented Dec 29, 2018 at 21:56
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    @LioElbammalf "hence the focus on unforgivables", does one example seem to you like focus? There is also mentioned- why Harry used Expelliarmus on Malfoy even though he has two magic wands? Why didn't he use Stupefy?
    – kocica
    Commented Dec 30, 2018 at 10:02
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    I think Filip hit the nail on the head. None of these are as good as Stupefy except possibly Jelly (isn't that one an area effect?).
    – Joshua
    Commented Jan 1, 2019 at 1:25


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. Harry dodged behind the golden fountain again. Her counter-spell hit the head of the handsome wizard, which was blown off and landed twenty feet away, gouging long scratches into the wooden floor.

Never used an Unforgivable Curse before, have you, boy?’ she yelled. She had abandoned her baby voice now. ‘You need to mean them, Potter! You need to really want to cause pain – to enjoy it - righteous anger won’t hurt me for long – I’ll show you how it is done, shall I? I’ll give you a lesson –’

There is something beyond just casting these spells (I've never heard of Expelliarmus not working because the caster wasn't really sure they wanted to disarm someone or Alohomora not working because you weren't sure you want to find what's behind the door). They aren't as effective if you don't mean it.

Imperius curse:

They’re Imperiused,’ he added, in response to Hermione and Ron’s confused queries about Travers and Bogrod, who were both now standing there looking blank. ‘I don’t think I did it strongly enough, I don’t know …’

And another memory darted through his mind, of the real Bellatrix Lestrange shrieking at him when he had first tried to use an Unforgivable Curse: ‘You need to mean them, Potter!”

We can see that perhaps some level of skill or desire is needed here - the memory of the earlier event seems to imply it is a desire or malice that is needed.

Avada Kadavra:

Avada Kedavra’s a curse that needs a powerful bit of magic behind it – you could all get your wands out now and point them at me and say the words, and I doubt I’d get so much as a nose-bleed. But that doesn’t matter. I’m not here to teach you how to do it.”

And Snape uses it to kill Dumbledore - I doubt he really wanted him to die - so Avada Kadavra seems to take power, rather than desire. Voldermort is spoken of as one of the most powerful wizards and uses Avada Kadavra frequently throughout the first and second wizarding wars. So it seems power (and perhaps practice) are factors with this one.

So why don't they use them?

The three unforgivable curses are forbidden, it is unlikely that most, especially those on the 'good' side, have practiced them. When your enemy is bearing down on you do you want to try something you know – like Expelliarmus – which can save your life in this moment or do you attempt an unpracticed spell that relies on power you may not have or a desire you don't truly feel but could, if successful, defeat your enemy. I imagine most would go for winning in that moment.

Another perspective comes from looking at our own world. Introduce a more dangerous weapon to any arsenal – be that gang crime or international relations – and soon everyone is using it. You see it in gang crime, once you know your enemy may be carrying a knife you don't leave your house without one and if the US fires a nuclear missile at Russia (or vice versa) and the response was a nuke in return... how does the world fare then?

This part is conjecture but perhaps at the back of every witch and wizard's mind is the awareness that there aren't so many of them and pulling out avada kadavra as a first resort will only encourage the other side to do the same.

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    This does a good job of answering only one aspect of why people don't run around using just the three Unforgivable Curses, but not why people don't use the most effective/deadly spell for a given circumstance (e.g. why did Harry cast a torture spell instead of a straight-up harming/damage spell, or a disarming spell instead of a stunning spell)?
    – TylerH
    Commented Dec 28, 2018 at 15:21
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    @TylerH the success rate of expelliarmus is greater than stupefy that is the point. It is even lower for the UCs. In combat, precision, accuracy and reliability matters more than potency. Commented Dec 28, 2018 at 16:01
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    @TylerH In the first case quoted above, Harry goes for Crucio because he's blinded by rage. He's not thinking clearly, or he presumably would have chosen a quicker, more reliable spell.
    – Cadence
    Commented Dec 28, 2018 at 16:29
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    The spells may take intention, rather than just desire or power. Snape most certainly intended to kill Dumbledore, whether he desired it or not. Harry is probably not only just reluctant, but actively unwilling. He is never unwilling to disarm someone.
    – jpmc26
    Commented Dec 29, 2018 at 0:13
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    I think the unforgivable curses are really a red herring here, and thus this answer misses the point. The thrust of the question isn't so much about why they don't use unforgivable curses; I think that's self-evident to most of us. The more-interesting idea in the question is why they use expelliarmus rather than stupefy. One leaves the bad guy sitting there free, ready to pick up any available wand, while the other completely incapacitates in a harmless way. Commented Dec 29, 2018 at 20:48

This seems to be due to some sort of "morality" that some of the good-guy wizards believe in, most notably Harry and Dumbledore. We know Dumbledore particularly avoided killing, as Harry stated at the end of Deathly Hallows:

"Master of death, Harry, master of Death! Was I better, ultimately, than Voldemort?"

"Of course you were," said Harry. "Of course – how can you ask that? You never killed if you could avoid it!"

And Harry had a bit of a heated exchange with Lupin after the battle at the beginning of Deathly Hallows. Some of Harry's choice lines from there:

"I saw Stan Shunpike.... You know, the bloke who was the conductor on the Knight Bus? And I tried to Disarm him instead of – well, he doesn't know what he's doing, does he? He must be Imperiused!"

"We were hundreds of feet up! Stan's not himself, and if I Stunned him and he'd fallen, he'd have died the same as if I'd used Avada Kedavra! Expelliarmus saved me from Voldemort two years ago,"

"So you think I should have killed Stan Shunpike?" said Harry angrily.

"I won't blast people out of my way just because they're there," said Harry, "That's Voldemort's job."

Although in that instance Harry was specifically talking about Stan Shunpike, whom he believed to be innocent, it seems from Lupin's responses (as I argued here) that Harry was against severely attacking even actual Death Eaters.

For whatever reason, Harry, Dumbledore, and perhaps others seem to believe that it is wrong to kill Death Eaters — even if that gives the Death Eaters have future opportunities to kill others.

In truth, though, for all his experience and D.A. lessons Harry is still a novice. He doesn't actually have a repertoire of many damaging spells. Stupefy and Petrificus Totalus might be a step up from Expelliarmus, but under normal circumstances the Death Eater can be freed from those within moments. Harry has never demonstrated the ability to perform Avada Kedavra, and his Crucios are mild at best. The only other powerful curse that we really see him use is Sectumsempra, and even that would not necessarily incapacitate an enemy, and could be counteracted by a knowledgeable wizard. So even if Harry did not have these moral compunctions there is not all that much more that he could have done. Harry is simply overrated. To quote our favorite Potions Master from the end of Deathly Hallows (my emphasis):

"– mediocre, arrogant as his father, a determined rule-breaker, delighted to find himself famous, attention-seeking and impertinent –"

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    As I recall, Sectumsempra was a curse invented by Snape, which means he alone knew the counter curse to heal Malfoy when Harry used it on him (and it definitely incapacitates the target; Malfoy was limp on the floor, gushing blood after being hit once). Whether counter curses can be 'divined' or 'reverse engineered' by someone else, such as a skilled healer, in the Harry Potter world is pretty much unexplored.
    – TylerH
    Commented Dec 28, 2018 at 15:25
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    Also, FWIW, we see Harry first start to show some level of proficiency in combat magic during the Tri-wizard Tournament in GoF. He mentions when giving the sack of galleons to the Weasley twins to start their joke shop that if they go against his wishes (or something like that), he'll hex them, as "he knows some good ones now" (and the book shows him using some during the Maze trial). Certainly by the middle of Deathly Hallows he's fairly proficient in that kind of magic, having lived on the run with Ron and Hermione for nearly a year, learning powerful magic to combat Voldemort.
    – TylerH
    Commented Dec 28, 2018 at 15:30
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    Finally, where in Deathly Hallows is that final quote from? IIRC it is a flashback memory of Snape to when Harry was still 11 years old, not real-time to when Harry is practically an adult.
    – TylerH
    Commented Dec 28, 2018 at 15:31
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    Further, there's nothing surprising about the morality of not killing dangerous criminals. In fact, it's standard procedure in many countries to attempt to apprehend even armed killers alive. And this is in the real world, where nonlethal methods of subduing people are simply not as effective as lethal ones - unlike Harry Potter, where there is no indication that lethal curses are more effective at subduing opponents, save for the extremely difficult Avada Kedavra.
    – Adamant
    Commented Dec 28, 2018 at 18:07
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    Nor would anyone be too worried about these criminals escaping to kill again, compared to real life. Highly skilled and dangerous Death Eaters, such as Bellatrix Lestrange, were readily imprisoned for 15 years, and none escaped without outside help. Gellert Grindelwald, who could duel a dozen Aurors, was imprisoned without Dementors for 50 years and never escaped. There's not much reason to think that magical society's prisons are less secure.
    – Adamant
    Commented Dec 28, 2018 at 18:13

Bellatrix's answer touches on an extremely important point, although I don't think it is emphasized enough: wizards are people, and most people are conditioned from childhood not to hurt other people. It's called civilization. It can be very difficult to cast aside.

The classic treatment of the subject is S.L.A. Marshall's "Men Against Fire", which dealt with the behavior of US infantry soldiers in actual combat. There has arisen very considerable doubt that his numbers are honest, but he concluded that in general in a company under attack only 15% of the soldiers would actually use their weapons, with as much as 25% for elite units "under intense local pressure", which is mil-speak for the situation going to Hell in a handbasket and a really desperate fight. He also remarked on the fact that the same names kept cropping up for a unit fighting multiple engagements, suggesting that the same small proportion (less than 15%) were the mainstays of the unit when the bullets were actually flying.

It may be unrelated, but a post-D-Day study by Swank and Marchand concluded that after 90 days of combat, 98% of the physical survivors were psychological casualties, with the most common diagnosis of the unaffected being "aggressive psychopathic personalities". This does suggest that some of the best soldiers, in terms of combat effectiveness, were not what you'd call nice people.

Unless wizards are somehow qualitatively different from muggles psychologically, it would make sense that most would instinctively shrink from using the effective (unforgivable) spells, even if it meant that they would suffer for it. And, given the importance of whole-hearted intent in casting the powerful spells, any internal conflict would make attempted use less likely to succeed. And the same personality defects which would cause a person to side with Voldemort would tend to make his followers more likely to be able to use the unforgivable spells, at least as compared with the good guys.

EDIT - And about internal conflicts and effectiveness. WWI saw the recognition of what Freud dubbed "conversion hysteria" on a widespread basis among soldiers. This occurs when emotional stress manifests itself as paralysis of a body part with no organic cause. In the case of soldiers, it showed up as paralysis of the hand or even of the trigger finger. If the stress of trying to kill someone can produce such gross muggle effects, it certainly seems reasonable that a similar condition could occur among wizards, which would make casting unforgivable spells extremely difficult or impossible.

As a personal illustration, as a Vietnam helicopter door gunner, the first time I was called upon to fire with a visible target, I had to deal with the fact that for several seconds my trigger finger simply would not move. It was really the damndest sensation, looking at my hand which steadfastly ignored the commands which my brain was sending. This only lasted for a few seconds, but the experience left quite an impression on me.

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    It's a kid's book. The only ones who were 'combat effective' were the Dementors, whom were already literally relieved of their humanity. The over use of which would require a simple paragraph, not seven other books and six different movies.
    – Mazura
    Commented Dec 29, 2018 at 21:18
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    @Mazura - Your statement that "It's a kid's book." suggests that you want an out-of-canon answer. That one is simple enough. JKR simply doesn't know enough about how people behave in combat/kill-or-be-killed situations to write realistically, and if she did the result would not be suitable for kids. So she had to come up with a watered-down moral universe, which she did splendidly. As you put it, it's a kid's book. If the wizard world were real, the existence of curses like Avada Kedavra would result in a smoking ruin with mass casualties. Commented Dec 30, 2018 at 22:07
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    I like the real world answer with this one. JK would have to leave horrifying parts out of a kid book, just read how horcruxes are made and it becomes clear - both you and @bellatrix should both be marked as answer in my opinion. Unfortunately that's not how this site works so +1 is the best I can do
    – Matt
    Commented Dec 30, 2018 at 23:08

There are several reasons.

Many factors contribute to why most wizards don’t use Unforgivable Curses in battle, and each individual wizard who chooses not to use them may base their choice on one or a combination of reasons.

Unforgivable Curses are illegal.

Using the Unforgivable Curses is illegal - using any one of them is enough to get a life sentence in Azkaban. Even wizards who are capable and willing to use them may not if they consider the possibility of being sent to Azkaban for life over their use.

“Now … those three curses – Avada Kedavra, Imperius and Cruciatus – are known as the Unforgivable Curses. The use of any one of them on a fellow human being is enough to earn a life sentence in Azkaban.”
- Harry Potter and the Goblet of Fire, Chapter 14 (The Unforgivable Curses)

That’s likely a very strong deterrent to using them, even in serious situations, since no one wants to go to Azkaban. It also would work on some wizards who’d have no other problems with using Unforgivable Curses, because the consequences are extreme.

They’re difficult to cast.

Additionally, only wizards with a certain level of skill and power can cast Unforgivable Curses. As Snape tells Harry, casting Unforgivable Curses requires both nerve and ability.

“Cruc—’ yelled Harry for the second time, aiming for the figure ahead illuminated in the dancing firelight, but Snape blocked the spell again; Harry could see him sneering.

‘No Unforgivable Curses from you, Potter!’ he shouted over the rushing of the flames, Hagrid’s yells and the wild yelping of the trapped Fang. ‘You haven’t got the nerve or the ability –”
- Harry Potter and the Half-Blood Prince, Chapter 28 (Flight of the Prince)

“Nerve” likely refers to the desire to use the Curse, something that’s particularly important with the Cruciatus Curse. Crucio can cause varying degrees of pain, and the more you want to cause pain, the more effective it’ll be. A Cruciatus Curse that doesn’t have that desire behind it will be ineffective, so wouldn’t help much in a battle.

“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. Harry dodged behind the golden fountain again. Her counter-spell hit the head of the handsome wizard, which was blown off and landed twenty feet away, gouging long scratches into the wooden floor.

‘Never used an Unforgivable Curse before, have you, boy?’ she yelled. She had abandoned her baby voice now. ‘You need to mean them, Potter! You need to really want to cause pain – to enjoy it – righteous anger won’t hurt me for long – I’ll show you how it is done, shall I? I’ll give you a lesson -”
- Harry Potter and the Order of the Phoenix, Chapter 36 (The Only One He Ever Feared)

Avada Kedavra has only two possible effects - it either works or it doesn’t, it can’t kill someone any more dead if cast more skillfully than necessary, but it takes a certain level of skill and power to cast it effectively. If it fails, then it fails entirely.

“Avada Kedavra’s a curse that needs a powerful bit of magic behind it – you could all get your wands out now and point them at me and say the words, and I doubt I’d get so much as a nose-bleed. But that doesn’t matter. I’m not here to teach you how to do it.”
- Harry Potter and the Goblet of Fire, Chapter 14 (The Unforgivable Curses)

For a wizard that’s not skilled enough to use the Unforgivable Curses, it’d be more effective to cast a spell that they’d be successful at using that attempting to use an Unforgivable Curse unsuccessfully.

They’re also considered immoral by some.

Furthermore, some wizards wouldn’t want to use Unforgivable Curses at all, even if using Unforgivable Curses wasn’t illegal and they were skilled enough to use them. Dumbledore avoided using Dark magic entirely.

“I know you haven’t,’ said Professor McGonagall, sounding half-exasperated, half-admiring. ‘But you’re different. Everyone knows you’re the only one You-Know – oh, all right, Voldemort – was frightened of.’

‘You flatter me,’ said Dumbledore calmly. ‘Voldemort had powers I will never have.’

‘Only because you’re too – well – noble to use them.”
- Harry Potter and the Philosopher's Stone, Chapter 1 (The Boy who Lived)

It’s very rare to see a member of the Order use an Unforgivable Curse, which is likely at least in part to a desire not to use Dark magic. Moody, a member of the Order of the Phoenix, also had a similar set of beliefs as an Auror - he avoided killing, and likely Unforgivable Curses as well.

“I’ll say this for Moody, though, he never killed if he could help it. Always brought people in alive where possible. He was tough, but he never descended to the level of the Death Eaters.”
- Harry Potter and the Goblet of Fire, Chapter 27 (Padfoot Returns)

Sirius Black, another member of the Order, thought Barty Crouch Sr. went too far in his attempts to capture Death Eaters using violence against them, which included allowing Aurors to kill and authorizing them to use the Unforgivable Curses.

“Crouch’s principles might’ve been good in the beginning – I wouldn’t know. He rose quickly through the Ministry, and he started ordering very harsh measures against Voldemort’s supporters. The Aurors were given new powers – powers to kill rather than capture, for instance. And I wasn’t the only one who was handed straight to the Dementors without trial. Crouch fought violence with violence, and authorised the use of the Unforgivable Curses against suspects.”
- Harry Potter and the Goblet of Fire, Chapter 27 (Padfoot Returns)

Harry, Ron, and Hermione all seem very reluctant to kill Antonin Dolohov and Thorfinn Rowle, both notorious Death Eaters. Ron brings up the idea, but is clearly relieved when Harry rejects the idea. Hermione shuddered at the thought of it.

“What are we going to do with them?’ Ron whispered to Harry through the dark; then, even more quietly, ‘Kill them? They’d kill us. They had a good go just now.’

Hermione shuddered and took a step backwards. Harry shook his head.

‘We just need to wipe their memories,’ said Harry. ‘It’s better like that, it’ll throw them off the scent. If we killed them, it’d be obvious we were here.’

‘You’re the boss,’ said Ron, sounding profoundly relieved. ‘But I’ve never done a Memory Charm.”
- Harry Potter and the Deathly Hallows, Chapter 9 (A Place to Hide)

So, that’s yet another reason why the average wizard wouldn’t use Unforgivable Curses - some consider it wrong. Also, those who consider it wrong to use Unforgivable Curses are likely to be less effective at casting them, even if they tried, as they mightn’t be able to put enough power behind the Curses to cast them well.


As you say, the interesting question is why non-evil wizards ever use anything other than Stupefy in a combat situation, given that knocking someone unconscious seems strictly better than temporarily disarming them, immobilising them or slowing them down. Here are a few possible answers, largely based on evidence from the wiki (primarily pages for the relevant spells):

Casting spells seems to require concentration/mental energy (see wiki page on non-verbal skills, and the fact that we don't see people cast them as fast as they can say Stupefy/perform gestures). If less powerful spells demand less mental energy (seems plausible since they are taught before more powerful ones), using e.g. Expelliarmus over Stupefy might allow a higher "rate of fire".

There are also some tactical advantages to certain spells:

  • Stupified people can be revived by allies, so Expelliarmus could be better than Stupefy if it would deprive someone of their wand for longer than it would take them to be Rennervated following a Stupefy hit.
  • Various non-humans are immune to Stupefy.
  • According to the wiki, Expelliarmus can also reflect enemy spells which is obviously useful.
  • Different spells might have different properties with respect to shields and dodging. For instance, Petrificus Totalus doesn't seem to involve firing a beam, so it might be more difficult to block/dodge than Stupefy

Finally, although a single Stupefy is non-lethal, multiple simultaneous hits can apparently kill. So that's another reason for avoiding it if you're a goodie.

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    Regarding Petrificus Totalus having a beam that can be dodged: Malfoy jumped out of range of Hermione’s second Stunning Spell, and Ron, appearing suddenly at the end of the aisle, shot a full Body-Bind Curse at Crabbe, which narrowly missed.
    – Alex
    Commented Jan 2, 2019 at 17:25
  • @Alex Interesting! I was going off the wiki which shows "a mist-like effect issued from [the] wand" and "a faint white flash around [the target's body]".
    – rlms
    Commented Jan 3, 2019 at 15:38

I infer that because the wizards are usually in tense situations the easiest spells to pronounce and the spells that they are certain will work, pop into their head first. To support my answer,"Harry is fond of using the spells: “Expecto Patronum,” “Stupefy,” and “Expelliarmus”".The spell that pops up to me most there is "Stupefy" a spell that is easy to pronounce and surprisingly wont to any large amount of damage to the victim. "Stupefy" was taught to "Dumbledore's Army"in book 5, therefore being a spell that Harry would like the "Army" to use while in battle and Harry would not have chosen this particulate spell if he himself did not prefer it. Here are just several examples of harry using this spell in "tense situations.

-Death Eater; During the early stages of the Battle of Hogwarts Harry used this spell on a Death Eater.

Lucius Malfoy; Battle of Malfoy Manor

Fenrir Greyback; Battle of Malfoy Manor

Thorfinn Rowle; During a skirmish at the Luchino Caffe in 1997.(MOVIES)

Viktor Krum; During the Third Task of the Triwizard Tournament to save Cedric Diggory from the Cruciatus Curse Krum casted under the influence of the Imperius Curse.(MOVIES,BOOK)

As you to have noticed each of these times where Harry has used the spell stupify has been in an extremely tense situation and the only reason for this is due to harry being familiar with the spell, the spell being easy to pronounce and harry knowing that the spell will not fail him.

I rest my case

  • 2
    Can you support your answer with any evidence from the books (or movies, I suppose)?
    – V2Blast
    Commented Dec 29, 2018 at 7:26

It's just because of morality of the characters. Putting aside the Unforgivable Curses, there are many other spells that can be used in a duel that are much more powerful than Expelliarmus or Stupefy. For example, Expulso curse, which Antonin Dolohov used on the trio, or Confringo, the blasting curse, Incendio the fire making spell, and finally Sectumsempra, that Harry only used 3 times and never again, which shows he doesn't like violence.

Ultimately, this is one of my criticisms against J.K. Rowling, 'cause I find it so dumb that they adhere to that morality in war; a Death Eater is more dangerous than a person with gun, it's foolish to focus on disarming or stunning while they can easily get blocked, not to mention that someone like Bellatrix carries a knife herself.

  • Welcome to the site. You could improve this answer by specifying the books/films in which these various spells were used by the relevant characters. Commented Jun 4, 2021 at 3:43

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