Thread by @ghirapurigears

let's talk about Magic in D&D! and not cards, but arcane nattering with wibbly gestures and spidery words and throwing little balls of bat shit wrapped around sulfur at people and watching them explode

so back in the 50s, there were a lot of pulp novels of adventure, sci fi, and early fantasy. Among them were the fantasy short stories of Jack Vance, collected in a pulp novel called "The Dying Earth"

In these stories, there were wizards who could use magic, and in order to use it they had to memorize lengthy and complex spell formulas, triggered by a word or phrase. And once they used a spell, it was gone forever, until they memorized it again

and spellcasters could only memorize a certain amount of spells at a time, because of the mental strain, and stronger casters could get more. And as such, they relied on magic items and other devices which stored up magic to be used

Gary Gygax, father of D&D with Dave Arneson, was a huge fan of these stories, and lifted the system entirely for his ruleset. Mages and Priests had to spend time daily memorizing spells, and that was all they had until the next time they could memorize spells

So your average starting wizard, for instance, would know a small handful of spells in their spellbook, but only have 1 slot to memorize a spell for the day. and once they used it, that was it.

and wizards at low levels absolutely sucked. 1d4 hit points (a range from 1-4 as determined by the dice you roll at character gen), one spell, and maybe a dagger that did jack shit. They traded this by being unstoppable gods as they progressed, but living that long was rough

In later editions, it became easier to cast spells, and spell casters had more lower level spells available (no one wants to waste their one spell a day on light, for instance), but the idea of casting a spell has kinda remained the same.

you spent time studying and memorizing your spell loadout, you pick spells of the available lists to use (sometimes divided by spell casting schools like evocation or illusion or whatever), and you kept your material components on hand.

casting lightning bolt, for instance, required a piece of rabbit fur and an amber rod, because rubbing the fur on the rod makes static electricity you see. Fireball required bat guano and sulfur, which the astute might realize is basically just gunpowder

The idea of spell slots per day and having to memorize spells off a list is widespread in gaming, and you can see a version of it in final fantasy 1 and 8, and ff tactics especially.

So when you see the wizard's spellbook exiling a spell to copy it? that's you memorizing, casting and forgetting the spell, just as Gygax intended. (snapcaster mage is also a perfect D&D spellcaster)