@Interace Screws: Can be done well. See MGS & PSycho mantis where he would reverse player controls, blank out the screen, alter statues etc. It's very interesting if done well.
They can be done very well, I agree- though I'd be more liable to cite Eternal Darkness: Sanity's Requiem here than MGS (though I hear it was done pretty well, Eternal Darkness had it as a core mechanic.) Making you think you accidentally deleted your save game or exploded when you cast a spell was rather amusing.
The difference was that, in those games, the interface was good. It wasn't a struggle to get dwarves to do something. When it screwed around with you, you knew that it was screwing around with you after/during the event, and the frustration would turn into the appreciation of a challenge. In DF currently, if something odd is happening with your dwarves, you start looking around for the 20+ things that could cause it. Imagine adding the game deliberately screwing with you to that list.
It's not impossible to get it to work well; I just think it's going to be pretty hard.
MP, Mana Pools, other JRPG crap
Mana Pools etc. - I think limited MP is the dumbest invention ever. Now, casting spells should cause exhaustion, and tired mages can't cast spells, I'm fine with that. But saying "You have 8 MP and magic missle costs 2 MP each etc." turns magic from special into number grinding. Being able to min/max your spell usage ruins the magic of magic. Now, it's fine to say "I can only cast one big spell, two little spells, 3 tiny spells before my mage gets tired." but that also allows mages to be physically different. Cross-training a wizard to make him super-tough might allow him to cast more spells. None of this "levelling up" or "drink this potion to recover 6 MP" JRPG crap.
If magic's an important core mechanic that the characters understand, it should be described well to the player in terms that he can understand as well. Though I will agree the the MP system has all the nuance of a naked drunken ogre standing on a tank, it does tell the player what the wizard can do (something that the wizard should know himself.)
As far as magic being fatiguing goes, I'd be more willing to describe that as a specific facet of a specific magic system, rather than a widespread trait of all systems DF generates. Have the life energy of the mage be an additional common component in spells that gives it a bit more oomph.
Magic Items
[spoiler]
Perhaps RNG can help add a little mysticism. Perhaps if an "enchantment" class comes into play you can burn a lot of rare items to enchant a masterwork item (this would be a nod to D&D where only masterwork items can be magical). What the enchantment ends up being, or if it even happens or not is left up to RNG + variables, but I don't think it should ever be a guarantee and should come with a cost. So you enchanted the blade to deal extra damage? Oh no, it deals that extra damage to the user instead!
When how useful an item is is so fundamentally tied to luck, that encourages save-scumming and grinding out enchantments until you get a good one. Which is not fun.
I absolutely hate how D&D3.0 turned magic item creation into a set of forumlas. Why even bother having pre-made magic items. Just have a list of "features" to choose from and min/max until everything special about it is gone.
You might be surprised, but I completely agree with you. 3.0/3.5's magic items were pretty insipid, and the methods of creation were utterly uninteresting (toss lots of money, time, and -oddly enough- experience and you get a standardized magic item.) They did have formulas for making magic item if you check the custom rules, and IIRC that's how they priced all the magic items.
It (or something like it) was necessary to make magic items a core mechanic that was always guaranteed to be in the game and always be a fundamental part of a character's power. Dwarf Fortress shouldn't do that with magic items - the cost in terms of the presentation of magic is too great.
Magic as advanced technology
[spoiler]I can agree with taht to a point, but the point is that if it's advanced enough to be considered "magic" then it shouldn't be easily controlled. Imagine a caveman finding a computer, that sort of thing. If all the variables involved are "known" then it isn't magic, it's technology. Not even advanced technology because they understand it.
On something of a tangent- already, most of our technology is effectively magic to all but a few. If you don't have much background in electrical engineering/computer science, the computer you're typing at is pretty much a black box that you only know how to use because it's been designed to superficially behave in ways that humans think. Even if you do understand how the operating system + the software works, each bare circuit is still likely a mystery. And if that's not the case, you don't understand exactly where the electricity comes from and how. You just have a vague idea of "power plants generate electricity, which comes in power lines."
Of course it's not just pure magic; you have a few superstitions associated with it. Don't dunk the computer in water, magnets are bad for the TV, don't microwave metal, don't touch power lines or put pennies in light sockets. My point is that, yes, those have a legitimate scientific explanation for their danger, but most people don't know precisely why (and many don't care.) Mothers and politicians frequently generate new ones which are ludicrous, but that's only possible because they don't understand the technology.
To take this tangent back to the topic, that is exactly how magic behaves in any setting whatsoever in which there are people who practice magic. Like a computer programmer who generates working programs by typing gobbledygook on a keyboard, the stereotypical wizard generates fireballs by waving his hands and babbling nonsense. The sane people in the world have no idea why said programmer or wizard does each thing he does, but they call him a genius when he creates something useful that they don't understand (or a madman if said thing is dangerous.)
So IF something is special enough to be considered magic, it needs to have wild, random effects. Now, from a more advanced perspective, you would know "wind speed and trajectories and cleanliness of the gun alter results" but from a less advanced perspective, it was "random" whether the gun attacked your enemies, the tree next to the guy, or just exploded in your face.
THAT is magic, the "not understanding all the variables involved so the end result seems random."
The wizard follows a set system of rules to do so to achieve a predictable effect. And that system of rules was generated precisely because it had a predictable effect; if it randomly blew up half the time the wizard would either not use it or perfect it until it did. And if every spell blew up half the time, no wizard would ever survive long enough to be called a wizard in the first place. Any formula which fails half the time is not a formula, in the same sense that any experiment must have consistent results to be called an experiment. On these grounds, I'd call any magic system whose basic tenets failed half the time both impossible to have been developed in a fantasy setting as well as being a poor system to actually play with.
In other words, mad scientists don't exist in reality because the systems that they're working off of have to be consistent with reality, up until the very last leap of inspiration. Presuming that Frankenstein had a perfectly accurate understanding of human biology and that electricity really would revitalize a stitched-together corpse, he still wouldn't have gotten very far that metal conducts electricity. Mad wizards can't exist in fantasy settings unless they're handed the equivalent of a gun or a nuclear bomb that they don't understand - then they're much more the equivalent of a curious apprentice and not a mad wizard.
I was thinking about the idea of having a generic magic resource.
"Unknownium" (symbol would be a question mark). Fluid would work too (little question marks floating around).
To go further with the "magic is just unknown stuff" you'd find an unknown ore. You could build anything you want out of it, and there'd be a random chance it would be completely useless, standard quality, masterwork/artifact level, or super effective.
So an unknownium sword could be equivalent to a whiffle bat or could be instant death to anything it touched. The best part about this system is that it's unpredictable, but plausible (dwarves don't know what it does so they're doing the best they can) and because you don't instantly know if it's effective or not, you have to actually tset stuff out before you find out the sword spits fireballs or causes damage to the wielder or is just completely ineffective in combat.
Eh, unpredictability through pure randomness is a strong disadvantage in my book as I've already harped on earlier in this post. I wouldn't mind if, say, that material was connected to the [CHAOS] or [LUCK] spheres, but I would if that was the basis for all magic.
And having a single component for everything magical is quite boring, IMO. It prevents almost every interesting item creation out there.