Which game has your favorite magic system?

[Bill Zebub]

So far the one my group is playtesting seems to be turning out to be one of our favorites (GEAS).

No spell memorization or prep. If you know it, you know it. Every spell requires a roll. While no mishap table, if you roll all 1s (it's a dice pool system), it's a spell disaster. So far that's super rare (especially as you gain in power, your die in your dice pool go from d6s to d8s to d10s, etc.). Additional successes lead to greater spell effects. That's not the only way to make spells more powerful, as you can invest vigor (stamina pool) to boost your spells if you want. So a caster can really pump up a spell if they are willing to exhaust themselves doing it.

In addition to the above, the rune magic system is a list of runes that you combine into spell effects for a final spell. That really seems to be going over well for those players who like complexity and thinking outside of the box for creative solutions. An example includes combining a rune trap rune with a gust rune with a burst rune to send out the spell to a distance where it lays until triggered, then explodes. Basically an MLRS system in fantasy PC format lol.

I like the idea of a dice pool for casting. That nicely evokes the complexity/variability of how I think magic should work.

 

[Tony Vargas]

The best magic systems I've found, in the sense of enjoying them the most, have not really been magic systems, at all, but systems that let you decide how magic worked for your magic-user.

They've both been mentioned already: Hero System and Mage: the Ascension.

In Hero you can build up powers that model your character's desired system of magic in as exacting detail as you can stand (and afford the points for). When you're running, you can use package deals and campaign limits to essentially build a magic system or systems that works for your campaign/setting.
In Mage, you have one very flexible open-ended set of rules that you then fit to your character's "paradigm" to decide how he does his magick (if he even considers it magic), what it accomplishes, how it looks to everyone else, and what the consequences you face may be.

Among D&D-likes, one of the more intriguing magic systems I've seen was Ythgarth, which was old/primitive, but had a permisive multi-classing system, with different caster classes that essentially each used their own magic system, so you could get quite the range of characters out of it. Of course, it's been so long and I played so little of it, I could have that all wrong.

 

[Starfox]

One thing I dislike in many/most magic systems is generalization. That one mage/wizard/whatever can cast illusions, fireballs, raise dead, charms, etc. That feels Harry Potter-esque to me, where there's a spell for just about everything. If magic is roughly analogous to science, it would be like a Scientist class in a modern day RPG being simultaneously expert at cosmology, microbiology, neuropsychology, materials science, and (of course) rocketry.

Back in the renaissance, one person could master most of science. This is why we talk about renaissance men. That's the legend anyway. Many fantasy settings are roughly equivalent to the renaissance. I'm not saying it has to be this way, just how you can explain it if you want a wide range of magic available in your setting/game.

 

[Thomas Shey]

I'm a picky-butt so I like a number but have issues with all of them. Probably the ones I found most interesting were the two kinds of Node magic in Swordbearer, even though there were problems with them in practice.

 

[nogray]

I enjoyed reading about the Talislanta (4e) magic system. In it, you have Orders, which are like traditions of magic. They grant access to (and have bonuses and penalties that apply to) Modes, which are broad effect categories (Move, Attack, Defend, Heal, etc.). Some Orders may have no access to a particular mode. You take skill levels with each mode, so being a broadly-talented spellcaster can get expensive.

To cast a spell, the player picks the level (like base damage) and effects (part of the mode) and modifiers (like -1 to casting roll for each foot of radius of an AoE attack spell or each extra 10 feet past the initial 50 foot range), which sets the casting penalty of the spell. Roll a d20, add your skill at the mode, any order-based and other modifiers, and subtract the casting penalty of the spell. Rolling a total less than zero can cause a mishap, so those are possible, but only when a caster is "overreaching." Slap a name on the specific combination, should you so desire, especially for ones you might use frequently.

Most of the time, your cost for casting is -1 to further spellcasting rolls until you rest for the night. (Rolls totalling 20+ don't cause this penalty to accumulate.)

 

[Committed Hero]

My favorite was the d20 Modern ritual system supplemented by the occult correspondences of GURPS Cabal.