This blogpost now has a follow-up.
The vast majority of spells in Harry Potter seem to involve
- Aiming a wand
- Enunciating words precisely
- Waving the wand in a precise way
- Exerting enough energy or power
- Knowledge of the spell – either through learning or observation
This works great for a video game, all the precision can be timing of button presses and aiming with the mouse or the analogue sticks.
Mechanically these elements can be translated to a roleplaying game too. Investment of power can be handled by magic dice. You can also game-ify timing at the table.
And these mechanics would represent the fiction well.
But that fiction is still boring. The spells are basically fancy bullets.
Once you know what to do you just fire and forget.
There is no roleplaying-juice.
Except for Harry Potter’s three best spells.
Expecto Patronum
The Patronus Charm conjures a glowing animal spirit which lifts your mood with its presence. It’s used to defeat Dementors, spectre-like floating rags which suck all feeling of love, hope and happiness from their target.
To create an effective patronus, you need to hit all the conditions in the bullet point list at the top of the post. But you also need to bring a powerful, deeply-happy memory to mind and focus on it during the casting.
This is a great matching of theme and mechanism, since Dementors are a clear allegory for depression.
The caster has to do something (think happy thoughts) which the spell is going to amplify.
It’s also a great spell for a roleplaying game – asking the players what memory they’re thinking of, discussing what memories they could use, debating why a certain character is failing at casting the spell. There is a lot of roleplay-juice here.

Polyjuice Potion
I know its not a spell but it’s brilliant.
The Polyjuice potion allows the drinker to assume to form of another, for about an hour. A D&D analogue would be Disguise Self.
To make the potion you need a bit of the target – a strand of their hair, nail clipping, eyelash etc.
This is once again a great matching of theme and mechanism.
The caster has to get something (the body part) which the spell uses to know what you should look like.
It works well in a roleplaying game because the players will have to somehow obtain the body part. Woe betide them if they accidently get a cat hair instead of a head hair. In the books, the ingredients are also restricted (requiring stealth shenanigans to steal from the potions master) and it takes months to brew (requiring an isolated hangout to brew it in). Tasty, tasty roleplay-juice.
The spell which returns Voldemort to corporeal form in chapter 32 of Harry Potter and the Goblet of Fire
Okay its another potion. The fact that my 2 of my 3 best spells in Harry Potter are potions is quite telling.
The Dark Lord must perform a ritual to return himself from a withered husk to his full corporeal body. There are three crucial ingredients to be poured into the bubbling cauldron.
- Bone of the father, unknowingly given
- Flesh of the servant, willingly sacrificed
- Blood of the enemy, forcibly taken
This is a dark ritual. You need enemies, a servant who is taking care of your husk-form, access to the grave of your father and willingness to defile it. In the fiction, Voldemort also believes the ritual will be strongest with his biggest enemy, Harry. The wording of the ritual feels Shakespearean, and therein archaic and secretive.
In 5e, resurrection’s unique requirement is a high value diamond. Not very interesting, and one of the reasons why house-ruled resurrection rules are often touted.
I wouldn’t expect players to use this dark spell in a roleplaying game, unless they are meant to be baddies. However the general format of ‘get these three hard-to-obtain things so you can do the epic magic’ works well.

Bonus best spell: Riddikulus
A boggart will take the shape of something you fear. Visualising the thing you fear in a comedic situation (the giant spider is now floundering around wearing four pairs of roller skates) whilst casting the spell Riddikulus enables you to defeat the boggart.
Making the player visualise and describe how the embodiment of their fear becomes a source of mockery is more great roleplay-juice.
This is a bonus to the list because it retreads the ground that the patronus charm covered. Visualising humour to beat fear and visualising happiness to beat depression are just variations on a theme. Good variations, but variations still.
Applying the DAQ criteria
I wrote about the DAQ criteria previously here. You can use it to look at rpg character features by asking:
- Is it Distinctive?
- Is it Appreciable?
- Is it Qualitative?
Since Harry Potter does not have a class system, we should be considering whether the spells are meaningfully distinct from any other available magic.
Expecto Patronum: Is distinct as its the only spell that can beat dementors and lift your mood. It is appreciable (as its the only good way to counter a dementor, when you use it you definitely appreciate your knowledge.) It’s also qualitative – a spirit is summoned and you now feel happier (or at least, not-worse than you were to begin with). 3/3
Polyjuice Potion: No other spell allows you to take another’s form so it is distinctive. It’s quite appreciable, since there are teleportation spells which are less effort, it’s mostly useful for cons in areas of restricted access. It is qualitative, your form is changing. 3/3
Dark Resurrection Ritual: Definitely distinct as there is no other reasonably achievable way of bypassing death. Very appreciable – if you can avoid death you will always appreciate it. Very qualitative – going from dead->alive is a quality change not a quantity change. 3/3

The other spells in Harry Potter
The combative ones
There are a large number of combative spells in Harry Potter are basically guns/tasers with different skins.
- Stupefy – stuns target
- Confundus – confuses target
- Expelliarmus – disarms target
- Petrificus Totalus – freezes target’s body
- Any number of joke hex/curse/jinx spells that are included for their whimsical value, for instance, the bat-bogey hex or the slug-vomiting charm
Whilst I appreciate that whilst these spells are qualitatively different, most of the time it wouldn’t matter which one you used as they would all do the job – eliminate the target from the fight (at least for a moment).
All of these spells are qualitative and appreciable, but they are not very distinct from each other. So they probably all rate about 2/3 on the DAQ criteria.
Their main problem, for rpgs, goes back to the bullet list from the start of this post.
Once you know what to do just fire and forget
There’s no roleplay-juice here.
No added value.
The joke ones might get some humour and develop the feel of the setting, its true. Establishing the whimsy of the wizarding world (or reminding us of it) is just as useful in a game as in a novel. But they don’t give us much to speak to the character with.
The utility ones
There are many spells which exist as utility – these spells either need to exist for the setting to work or are obvious spells to write into a fiction
- Aguamenti – water making charm
- Incendio – fire making charm
- Wingardium Leviosa – levitation charm
- Apparition – teleportation
- Obliviate – false memory/memory wipe spell
- Accio – summoning spell
- Reparo – repairing charm
Whilst the Harry Potter books do explore the consequences of these spells at times, they are all entirely uninspiring renditions of their concept. They’re very obvious in their execution.
Your game might need spells like this, but I’m sure you can make them more interesting.
The overly specific ones
Mostly these exist to contribute the feeling of whimsy, or to flesh out the laughably undeveloped transfiguration branch of magic.
- Waddiwasi – summons chewing gum to fly at the target
- Vera Verto – turn an animal into a goblet?
- Orchideous – a bunch of flowers bursts from the wand
They are too specific to see enough use in a roleplaying game, where players are more inclined to optimise than book characters.
Given the opportunity, players will optimize the fun out of a game
Soren Johnson
The Unforgivable Curses
In Harry Potter, these three spells are unforgivable if used on another person, earning you life imprisonment in the wizarding prison.
- Imperio – mind control
- Crucio – torture spell
- Avada Kedavra – killing spell
But other magic can seriously mess with somebody’s mind – the mind-wiping spell Obliviate and the truth potion Veritaserum.
But other magic can torture – there are loads of nasty curses and jinxes designed specifically to belittle, disfigure or abuse.
But other magic can kill – powerful destructive spells such as Bombarda and Confringo.
This category of spell makes no sense to me. There’s also no added value to them.
Divination
CURVEBALL ALERT
Divination in Harry Potter is absolutely awesome.
It’s the best branch of magic in Harry Potter.
Theme = mechanics throughout.
You want information? Discern it from patterns in random, chaotic systems.
Tea leaves
Tarot cards
Palm reading
*Chef’s Kiss gesture and noise*
SECOND CURVEBALL ALERT
Divination is so good entirely because it is a copy and paste of real-life divination techniques.
What’s the lesson in all this?
Any Harry Potter inspired rpg would do well to add more flavourful roleplay-juice conditions and restrictions to their spells.
More generally:
Any roleplaying game would do well to add more flavourful roleplay-juice conditions and restrictions.
The pseudo-contrapositive:
Stop making your spells fire-and-forget fancy bullets.
Reminder to steal everything
I’ve talked before about why you should mess about with canon, modifying it to suit your game and reskinning it between genres. You should do this with the world of Harry potter too. Within the boundaries defined by law, of course.
Death of the Author?
I want to make it abundantly clear.
I reject Harry Potter’s author’s transphobic views.
I could write an essay on the problematic elements of Harry Potter. There are many. I won’t though, it has all been said before and this is not that sort of blog.
I would hate for anybody to think that the praise of some of the magic design in this post equates to praise of views which are oppressive towards them. It does not.
Joesky Tax
I’ve already given some useable statements/rules-of-thumb but here’s something that is useable in a concrete way. I re-mastered my Hippogriff generator from a previous Joesky Tax.

An unnecessary copypasta I made some time ago which I hope effectively demonstrates my feelings about everything Potter related that has been released since about 2011
Merlin’s Beard! What in the name of Dumbledore did you just say about me, you little mudblood? I’ll have you know I graduated top of my magical cookery class at Hogwarts, and I’ve been involved in numerous charity bake-offs, and I have made over 6 million confirmed pumpkin pasties. I am trained in Bertie Botts every flavour beans and I’m the top chef in the entire Department of Magical Transportation. You are nothing to me but just another student. I will pie-grenade you with precision the likes of which has never been seen before on this Earth, mark my Pottering words. You think you can get away with escaping from this magical train? Think again, mudblood. As we speak I am contacting the best aurors across the UK and you’ve still got the trace right now so you better prepare for the storm, muggle-lover. The storm that wipes out the pathetic little thing you call your life. You’re so expelled, kid. I can apperate anywhere, anytime, and I can pasty you in over seven hundred ways, and that’s just with my bare hands. Not only am I extensively trained in pasty combat, but I can turn my hands into spikes and you won’t believe what I can do with my Chocolate Frogs, which and I will use it to their full extent to make sure you stay on this train, you little goblin. If only you could have known what unholy retribution your little escape was about to bring down upon you, maybe you would have stayed on the damn train. But you couldn’t, you didn’t, and now you’re paying the price, you goddamn idiot. I will spike you with my particularly spikey spikes. This train doesn’t like people getting of it, kiddo.
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