For my money, Greg Stolze has some of the best Magic-writing advice in his RPG Reign: Namely, that one of the most important things to figure out for magic is what it -can’t- do and what it costs to use. The default assumption with D&D type magic is “Nothing”, but that’s not as interesting as having strong limits to play with, and makes it easier to see how it affects the world.
As far as I can tell, Stolze didn’t work on Mage specifically, but he was partially responsible for Demon: The Fallen and Hunter: The Reckoning. Both of which excel at pushing the players to think out realistic consequences to magical violence. So, now you have my attention. Anyway, I’ll stop chasing after White Wolf’s Alumni and poke something with a stick that really wouldn’t have been appropriate for the original post.
The problem with D&D’s magic system isn’t that it’s free. It’s that there’s serious discrepancies between the original design intentions and what ends up in game.
As a quick aside, it’s really important to understand where your baseline is, for D&D. For some things, the transitions between editions are, fairly minor. They change things a bit, but you’re still rolling a 20 sided die to brain some critter with your weapon and hoping for the best.
That’s not the case for wizards (and other spellcasting classes). The transition between AD&D and 3rd Edition seriously warped the way magic was presented to the player. It also seriously screws up balance, in a way that actually really irritates some AD&D veterans. (And, for disclosure, my native D&D baseline is 3rd or 3.5. That’s where I started, and what I expected as normal, until years later when I went back and looked at AD&D.)
In D&D magic for wizards (and most of the spell casting classes) are metered out based on a Vancian system. Named after the system Jack Vance used in his Dying Earth setting. The basic idea is your spell caster can commit a certain number of spells to memory. Two or three when they’re starting out, up to a couple dozen by the time they’ve ascended into Gandalf levels of power. They can cast each spell once. After that, it’s gone from their mind, and they’ll need to memorize it again before they can recast it.
And, of course, Tolkien is a massive influence on D&D. Wizards are very much in the Odin Wandering mode of powerhouses, once they’ve spent a few decades (or centuries) traveling and accumulating lore.
In D&D there’s also the concept of spells being segregated by separate tiers (called “circles”). As a wizard (or any spell caster, really) levels up, they’ll gradually get access to higher tiers of magic. These occupy separate memorization slots, and the spells get absurdly powerful, fast.
These more powerful spells are moderated by increasing costs. Literal costs. The example I used in the original post, about having a sack of diamonds worth five thousand gold, is actually a necessary sacrifice to cast the basic raise dead spell. Which means, being a wizard (or cleric) can get really expensive fast. A lot of players and DMs simply wave these costs because it’s a lot of tedious paperwork. Do you really want to have a character demonstrate that they have a dart, a powdered rhubarb leaf, and an adder’s stomach when all they want to do is cast Melf’s Acid Arrow at a bugbear that’s eating Disposable Party Member #16? On one hand, it’s not fun, but on the other hand it is a major element that keeps the system’s magic grounded.
The other thing that intermittently gets lost from a lot of campaigns is the idea that a Wizard needs to keep their spell book on hand. It’s actually a physical volume, and if it’s taken or destroyed, that’s it. They need to start over from scratch and put things back together.
I can’t remember if it’s technically house rules from someone’s homebrew, but I could swear there’s also occasional chances that higher tier spells would be incorrectly memorized, even by an experienced wizard, resulting in a spell fizzling, or worse a wild magic roll. (AD&D’s wild magic table for spells that get out of control is several levels of boggling.)
The other major problem is that spells get handed out way too gleefully in Third and 3.5. In AD&D, the Wizard spells per day are a little more conservative. They start with a single first circle spell, instead of 3 + some additional slots for high intelligence. But, they advance through the spell tiers at roughly the same rate… sort of. They get access to the second tier of spells at level 3, and the third tier at level 5. Which just means they get a few more spells to work with, except for one major thing. Third Edition streamlined the experience progression.
In Third, 3.5, and Fourth edition, everyone advances at the same rate. It’s 1k XP to hit level 2, 3k after that you hit 3, 6k after that you hit level 4. You can actually find this table online pretty easily, and it’s really simple. If you’ve got a party of players that are gaming together, they’ll hit their level ups at roughly the same time, so all the paperwork is done at once, and then out of the way until later.
But, in AD&D each class had a separate progression table. And, Wizards had one of the most brutal. An AD&D wizard and third edition character will hit level 5 at the same XP (the progression before that’s off by a bit), but, then Third edition characters start cooking with gas. (Incidentally, I’m using the Baldur’s Gate 2 manual for the AD&D XP progression, because it’s the most convenient thing at hand, I could be messing these numbers up a bit.)
This wouldn’t be a real comparison except, in AD&D the non mages, will also be leveling up faster. So you have a system where wizards need to spend a lot of time very carefully advancing through the world, scouring everything, to reach a new level of understanding and power, while you’re fighter’s off clocking heads, and your thief is engaging in their time honored craft of murder.
At higher levels these numbers go absolutely insane. Getting an AD&D wizard to level 12 takes roughly three times the experience what it takes to get a Third Edition character there. Advancing from 12 to 13 takes over 1 million XP in AD&D, while that same amount of XP will put a Third Edition character almost to 19. Given that 18 is the level where you get access to the final tier of spells, and a 12 has only just gained access to the sixth tier, there’s an issue.
So, in migrating the spell list from AD&D to Third, there’s a serious, unintentional, power creep, that results in godlike mages at a shocking speed. This was actually a pretty major sticking point for a lot of amateur game designers and some players, because as you said, it makes magic in Third Edition feel costless. It also makes some stupidly powerful spells available to relatively inexperienced characters.
This is also where we get into the other big problem with D&D, which TV Tropes gleefully dubs Linear Warriors, Quadratic Wizards. For most classes, a new level means they’re now slightly better at hitting things, and get to add one to the D20 they’re rolling to slap something senseless. For Mages, that’s actually a whole new surge of powers. Sometimes it’s just a new dice of damage on the spells they’re using (doubling the effectiveness of that new spell they got last level), but every other level cranks them up a bit further. Now, in AD&D Wizards do eventually outclass everything on the board, but it comes a lot further down the line, when you’re already in Odin Walking territory.
And before someone wonders, all told, I much prefer 3.5 over AD&D. A lot of the needlessly complex systems got streamlined down to something that was easily manageable, while still leaving the player with a lot of freedom to define a character. It’s also a hilariously broken and imbalanced ruleset, and not something I’d recommend for your writing. And any writer that thinks that, “so my character gets an attack of opportunity against the thug that’s bull rushing her, so I’ll use circle kick…” No, just, please, don’t. It’s a deep and fantastic strategy game, but it’s about as realistic as XCOM.
That said, some of the campaign settings do have fantastic world building. So, there is stuff to use there, it’s just going to be buried behind a lot of math. And, while I’ve never gotten into the D&D tie in fiction, there’s a lot of stuff there to dig through.