Coins on a well

Effect

The person casting the spell can materialize any material wish they choose. There are no limits on size, shape or state, but there isn't ownership over the materialized object either.

Secondary Effects

Only those caused by the existence of the object "wished for". So, yes, there are no magical restrictions to what you can ask for, but... you may want to be sure that it will at least fit the room where it will show up.

Manifestation

Are those shrieking sounds part of the spell, or just the distant screams of the "coin" you dropped into the "well"? Either way they are always there. At first, the light is too bright to see what's happening, and by the time you can actually focus on it, it looks as if it was unraveling and its darker insides look like shadows at first but slowly take shape until it becomes the object or substance asked for.

Technical details

Source

Nobody knows what exactly lays in the bottom of The Pit and the principal is the only person who has been close enough to witness its natural effects on the surroundings, but many people died before the walls were build, and terrible things had happened when the rules aren't followed.
Some say that if the real nature of that magic was known, nobody would be using it at all.

Caster

In normal circumstances, it takes a very powerful and daring witch to even approach the kind of magical source required to "grant a wish", but here at the Academy that's not an issue.
The spell itself doesn't require experience or power, just determination, even when some think that that's what the source of that magic wants you to believe, that the price is higher than we can imagine.

Components

A living human being to drop on the pit.

Something that belongs to the caster.

A very detailed description/mental picture of the wish.

If it's something the caster is familiar with, it's enough to just thinking about it, even if they don't know or understand its composition or how it works.

Anything that has physical form/manifestation works.

Drawing a model or blueprints, or even writing a list of characteristics help many casters to have clarity about it

Any unfilled detail will be completed as needed to make possible the specified elements, so being vague may have unexpected results but the wishe itself will be fulfilled.

The aspects of the wish involving intelligence, emotion or any sort of consciouness are simply ignored, disregardless of what impact it would have in the results.

Process

It's important that, before starting the process, you have a clear idea of what you want to obtein, that's the key element and sometimes the most difficult part.
Then, you lure another person to one of the entrances of The Pit. The usual strategy is to convince an outsider to enter the chamber coming from the drawing room while that door is ajar, but those who like a challenge will use the door on the laboratory or try to use another witch as coin.
Sometimes the person will need a little push to actually fall, and some books and rumors say that if they fall or jump on their own the wish won't be granted, but that is not true.
As the person falls, focus on your wish, until it starts materializing itself. Once the process has been triggered, you don't need to picture it anymore, just wait.
Sure, you can go and take a nap or have lunch, but remember that the summoned wish is not your property (even if it has your name on it or if you decided that it was yours). Finders keepers!

Discovery

The principal has never explained this to anyone, but she found this magic source by coincidence during the construction of the school's building.
She didn't know exactly what it was, but the danger was evident and she decided to try and find out if it could be controlled or at least directed towards a different target. It cost the life of a few workers, and a bit of the principal's youth, but eventually she figured out that this was an underground current, with dark magic flowing instead of water.
Any spring it could form would bring death and horror. Fortunately, it wasn't in a hurry to go to the surface. The construction works had opened an easy way for it to do so, but it hadn't abandoned its established route. All the incidents were mere side effects.
That meant, of course, that she could invent a way to control the interaction with that magic, using a lot of barriers... or creating an easily manageable well using the very energy that was flowing there.
It would take a long time for someone to figure out how she had done that, and even more before somebody else dared to try and repeat the trick, even when it's the only "safe" way to interact with whatever that thing in The Pit is.

Related Discipline

Dark Magic

Related School

Summoning

Effect Duration

Permanent

Effect Casting Time

Varies depending on the wish

Applied Restriction

The magic comes from the "well", therefore the spell only works close to that magic source.