Magic ain’t as mechanical as all that
One of the oft-recurring complaints about the basic magic system from GURPS, the one outlined in the basic book and then expanded in GURPS Magic, is that it’s too mechanical, it’s too “nuts and bolts” instead of “sense of wonder”. I’m not so sure.
From one angle, any magic system you care to mention is going to be, to some extent, “mechanical”. GURPS is a role-playing game, and the goal is for people to play the game. Sooner or later, shorn of all the frills, it’ll come down to a question of adding up modifiers and rolling some dice. Most likely, three dice. You can try to change it up and inject further randomness with different props or GM fiat, you can shake the Magic 8-Ball, but it’s all just modifiers. You’ve got to have a way to resolve the action at the table, and that method of resolution is going to have rules… even if the main rule is “bribe the GM with pizza”.
It could be that “sense of wonder” isn’t a big goal anyway, even if you are running entirely free-form and diceless. Tolkien had it easy, he could wave a hand and say “Look, elves!” and get all the starry-eyed wonder you could ever ask for. If I try that stuff, my players aren’t going to go all Samwise and get gushy about finally seeing the pointy-eared shiny people. They’re going to mug ’em and take their hand-crafted cruelty-free wallets. I reckon the closest I’m going to ever get to “wonder” is more “shock and awe”, and the way I’ll get it won’t be through the mystery of magic, it’ll be through some giant lizard rolling in and incinerating Alric in one breath.
(Sorry, Alric, just an example, you know I love ya!)
(But you do know, the first time a dragon breathes in this game, it’ll either be directly at Alric, or it’ll be because Needles crit-failed a Stealth roll at a very, very bad moment.)
I’ll count it a win if I can get the trappings of wonder. When it comes to magic, that pretty much means that your poor man’s Gandalf has to be able to mutter darkly about not tampering with forces beyond our ken, and the party has to be a little fuzzy on the wizard’s limits.
The muttering, you get for free. According to the standard magic system, if you crit fail while casting a spell, you get a roll on the Critical Spell Failure Table. Most likely, that means the wizard is down some Fatigue and everybody gets an amusing light-show. Sometimes, it means that a simple cantrip just summoned an angry demon. Statistically, Gandalf is going to roll an 18 once out of every 216 spells he casts. If your wizards are casting spells at 15 or less effective skill — a rarity, I admit, especially in DF — the number of spells between possible demon-summonings goes down.
During the Deadlands-inspired Old West game, we used the huckster magic system from the 3rd Edition GURPS Deadlands: Weird West. The player of the huckster character was always claiming to be exasperated with the others, whenever they asked him to cast spells. “Don’t they realize I could draw a black Joker at any moment, and end up possessed by an evil spirit? Where would they be then?” The huckster system had much higher odds of an explosive accident, since the spell caster had to draw several cards from a deck of 54 every time. Even so, it never came up in play, that I can recall. The huckster character was in more danger from the other PCs than he ever was from brain-sucking spirits.
If the rest of the party — the characters, not the players — knows exactly what the wizard can do, magic is just another technology. It may seem that way to the players, but to the characters, there’s still plenty of mystery.
First, there’s mana levels. A factor that the members of the party without magical awareness can’t sense. They’re just walking along, and suddenly the wizard’s muttering again and everybody’s magic items go dead. If your campaign includes Very High Mana (and mine does!), it could go the other way, too: walking along, minding their own business, until a moment when the wizard looks all overjoyed, starts casting spells like a thundercloud sheds rain, and then explodes when a regular failure goes critical, or a critical failure goes nuclear. A couple of experiences like that, and the rest of the party will be only too happy to agree that magic is a subtle and fickle art.
Mana’s even tricky for the wizard. Remember, a mage can’t just “feel” the local mana level. They can detect the boundaries between different mana levels, with a Perception+Magery check, that’s at -3 if they’re not specifically searching for a boundary. That modifier tells me that we’re talking about noticing something small, something one has to pay attention to if one is going to notice it at all. I would think further modifiers might be in line, if there are significant distractions at the time the boundary is crossed. Furthermore, I don’t see anything saying that the wizard who notices the boundary can tell the relative levels on either side of that boundary without making some tests…
If you need more muddy in those waters, there’s all sorts of things you can do. Ley lines come to mind. Another possibility would be to work up some sort of mana-based “weather”, so conditions can change over time.
Mana aside, it’s still pretty hard to be sure you know all of your party’s wizard’s capabilities. A new spell only costs a point, after all. In DF, it’s even harder to keep track, what with the Wild Talent advantage being right there on the Wizard template.
The great thing about Wild Talent is, it can represent many different things, depending on one’s interpretation and the character’s explanation. Maybe the wizard crafted that one-off spell from the raw stuff of magic itself. Perhaps it was some half-remembered scrap of a spell taken from a long-lost book that the wizard stumbled across during unrelated research, weeks ago. Or it could be that wizards know hundred and hundred of incantations and magical spells, each involving the application of astrological calculations and the cajoling of higher spirits, all of which are summed up in the two- or three-dozen lines on the character sheet under the “Spells” heading, and the only reason Jed can’t throw a Great Wish every day is because he only knows a few versions that only work when the stars are right… it’s just that the stars are only right once per game session per level of the Advantage.