I received the comment below on a 2010 post, from Taren. It's a good chance to change the subject. The comment has been slightly tailored; be sure to have a look at the whole:
"I have a question about your handling of the spells... so let's say a caster has his 8 spells learned and those are what he has available for the day... and forever (until he goes up levels). How do you handle the idea of having the character discover new spells or learn from a defeated wizard's spell book? Do you allow the character make a change to his list at some point, and have that be the new list henceforth? Would your character have to wait until he acquired a spell slot at a new level? I ask because I have in the past liked giving unique spell books or spells as part of a hard-won treasure. I'm wondering how you handle that sort of thing."
Starting with the post about magic changing the world, I've been hearing things suggesting that magic is seen very differently by many people in the blogosphere than how I see it. Two examples (among many others) would be the ability of one person to pour magic out from their hands like a flooding river or the idea that 1 person in 10 could be possessed of magic. I find both ideas ... bewildering.
Let us say that magic exists, but that it hasn't been 'discovered' yet. That is, the exact sequence of phrases, gestures or mindset hasn't been stumbled upon, or perhaps it was but it has long since been lost ... and all this time we've been living in a world with magic, but that it's hidden to us. This would mean that everything we've learned from science (which is a methodology and not an ideology, though it is often described as one by those who do not understand how it works) retains its merit. Moreover, physics continues to function as it always has, only that it can be circumvented by means that we as yet do not understand.
A sword, then, still swings through the air like a sword. It still resounds upon armor, it still cleaves flesh. The physical means by which the sword is compelled remains one that is exhausting, and one that takes experience and training to employ well. It is an effort, not merely physical, but mental as well, and as one swings a sword for several hours, surviving in a battle that rages on and on, one's mind degrades from dehydration, sugar depletion, excessive hormonal activity and so on. Hell, five minutes of such work would be enough to leave the fighter panting and needful of a moment's respite ... which good training acknowledges, as full-on physical and mental activity is debilitating.
We must assume, then, that magic, engendered somehow from or through the user, either as a source or a conduit, must also be at least mentally exhausting. Consider that I want to do something simple, something first level, like employing spider climb to scale a wall. What is the spell, exactly? What are the physical manifestations? Game editions don't care about things like this, because they're not about imagination, but rather about mechanics, but let's examine what must be happening. The fingers and body of the recipient must be somehow modified in order to make them able to climb the wall. The body is reshaped, perhaps with Peter Parker's finger spines, or it is magnetized in a manner that allows adherance even to non-metallic surfaces. At the very least, the recipient's body has been loaded up with POWER, which it is presumed has no effect upon the recipient either mentally or physically. The person can just climb walls now. That's the only change.
What kind of remarkable control does that require? I should think, if any sense of reality is there to be embraced, it must be a spectacular amount of control. Overloading the recipient in some manner could conceivably kill them, whereas too little power will have no effect. This is incredible fine-tuning on the dial, which the user of magic must employ with perfect ability. How long does it take to learn to tune this finely? Can it be picked up in a day? Or does it take a long time? If one has already learned to tune other spells, does it automatically follow that every spell is tuned to the exact degree?
How about this flow of power? Sitting here quietly, not producing magic, only compelling my fingers to move quickly over a keyboard, I can feel the effort. My knuckles feel the tinge of arthritis. I occasionally make a spelling mistake, which I fix, or I make a typo I don't notice at all. I'm acting quickly, but I'm in a quiet room, without distractions, thinking my way through this post and feeling relatively quiescent. I would find it particularly difficult to write this post in the midst of a raging battle.
So as a user of magic, I'm fine-tuning this immense power that is flowing through me, feeling my stress rise, my blood pumping harder to compensate for the effort that only my brain is using, just as an astronaut learns to control their body functions, their stress, which is amazingly difficult to do when out in space and in an extraordinarily dangerous environment. Using the mind in that environment is taxing in the extreme. Similarly, the user of magic is in the midst of a battle ground. He or she has no armor, no meaningful weapons, and they have to concentrate amid swordblows and movement, screaming, men dying, while they fine-tune the shit of out that magic to a perfect, non-dangerous degree. As the power pours from them, or through them from another plane of existence, how many calories does that burn? What is the depletion to their platelets and their hydration? How is it they're able to cast spell after spell without any apparent effect to their ability to move, walk, breathe and so on?
Training. Lots and lots of training. Phenomenal amounts of training. Training that goes past what's done with the sword, far past what is done with one's hands in a stressed environment operating complex and precise apparati. Training on levels we haven't yet sought for. As much training as a doctor receives. Potentially much more.
Let's consider a doctor. The first knowledge they gather is general knowledge - and there is a hell of a lot of that. To become a general practitioner requires terrific amounts of memory, and the ability to regurgitate that memory at will, preferably without many mistakes or having overlooked something. This takes years. And then, if that doctor wants to learn to do something specific, like heart transplants, this takes even MORE time. The process is slow and methodical and requires not only patience, but aptitude. Merely knowing how to do it or having the will to do it does not necessarily mean that one has the emotional strength to gut out the process. Many, many doctors who want to be specialists in some capacity don't make the cut. That is why there are so few people who can perform those very difficult surgeries that some of us need, and which we must be flown to Atlanta or Geneva in order to receive.
Now, here is our user of magic. Let us call him Bob. Bob has had his training (an extra 2d8 years according to the DMG, but traditional elves have had even longer to get good at this - or maybe they're stupider than humans and it takes them longer to learn the same spells humans do). Bob has spent his years trying to move a feather and light a candle, and while a lot of the stuff his tutor tried to cram into Bob's head hasn't taken yet, Bob is strong enough to throw spells 3 times a day (I'm going to go back to original D&D ideas here, so suck it up Pathfinder lovers). After three, he isn't "out of spells" ... he's exhausted. He's blown his ride. His heartrate has hit the ceiling, his mind is mush, and he's doing pretty well at that point to throw a weapon - badly - at an enemy. He hasn't practiced his weapon throwing skills because he was trying to get that fine-tuning just right, so that he didn't blow himself up when he tried to cast his shield spell.
But as Bob does more of this, and grows experienced, he realizes in a flash what his master was trying to say about that damn sleep spell over which Bob never got the hang. We would say Bob was second level, but really he's just learning to control his heart a bit better, to give himself more endurance, and that fine-tuning is coming easier to him ... now he can throw four spells before hitting his wall. And at 3rd level he can throw five, and at 4th level he can throw seven. And so on. That wall is getting farther away, he's learning little tricks and he's picking up on methods of channelling that energy that never occurred to him in the dull laboratory of his tutor. Bob is seeing his way to being a wizard.
This makes sense to me. What does not make sense to me is Bob stumbling into a tomb, finding a scroll, and instantly being able to cast that spell at will ... like a surgeon watching some innovative brain operation, shoving aside the attendant surgeon and then taking over the operation. That's the sort of thing that happens in bad television in the 60s, where the doctor is a TV Star ... but I can do without it in my D&D world.
Can a user of magic suddenly change their minds about the spells they have? Can a surgeon suddenly be an engineer? Or an astronaut? No. It took a lot of practice and training to use THOSE spells. This is how the process is conceived of in my world. I recognize that it compels the player to live with the spells they have, but ... sorry, no sympathy. Work with what you've got. That is the game. Circumventions in skills and abilities are ideas that were spawned by players who could not learn to work with the skills they had. Next time they play a user of magic, they can try different skills. They can try a different class. But no, I'm not interested in do-overs with the same character.
From the above, it should be possible to reason out the rest of Taren's questions. It isn't about how I apply the mechanics to my game. It is all about how the reasoning behind the game demands mechanics that FIT the process.