I've been thinking about ways I want to use magic skills in a setting I am working on. But I wanted to run this idea by the community noodlers.
Summary: different characteristics for different spells.
One of the biggest complaint about magic that I've seen about magic is that it's too broad. You can do nearly anything with a simple magic skill check. The CRB considers this, and offers suggestions to make higher difficulties for magic skill checks.
Working this problem through my brain I realized I don't like the idea of an Arcana skill user dumping everything into Intellect and then being a superhero capable of doing everything under the sun with an Arcana (Intellect) skill check.
My theoretical solution: different spells use different characteristics! Boom, nailed it. This will not only resolve my issue with casters being a one characteristic pony, but also force some interesting roleplaying narrative because the caster uses different characteristics for different ways of casting magic spells.
I can even use different characteristics for different spells for different skills.
I posted this idea to a comment on reddit, but it's a good example.
Say you're making an Avatar the Last Airbender/Legend of Korra type game. Bending is manipulation of elements through magic. For this game you might create the four elements (or more) as skills. Now, using the idea to change characteristics based on what spells you are using with those skills can definitely change the flavor of the casters and the skills as a whole. Earth bending skill that uses Brawn to cast the attack spell, but Willpower to cast the Barrier spell. Or Air bending skill that uses Agility for the Attack spell and Cunning for the Barrier spell. And so on.
Personally, I think I am going to develop this idea a bit further in my setting because I really like the versatility of magic, but I don't like the idea of making magic of a certain type all linked to the same characteristic. This simply reinforces the D&D-like fantasy tropes of the squish caster. I want my casters to be diverse, even the same skill using casters. I don't want all the wizards in my setting to be super smart and then have minor bonuses in another characteristic or two.
My setting is definitely going to use a type of magic called shadow magic. I can envision the Attack spell using Presence; a Shadow mage attacks outward with their inner force of personality, but Barrier might use something like Cunning, Shadow mages use deviousness to create barriers of darkness that obscure or confuse the opponents.
If I add an Elementalist magical tradition skill, the Attack spell characteristic may be cunning for the ability to weave power into a damaging force through creativity, sort of like Green Lantern powers making elemental shaped constructs to lash out at enemies. Then an elementalist may use Agility to cast the Barrier spell, I can imagine the elementalist is waving their arms around producing a fire shield or a wall of air, and they need to move their arms quickly for the construct to keep the shape.
Religion is a central theme to my setting that I am creating. Perhaps the Attack spell will use Brawn for the Faith magic skill, the pious mages channel their divine might straight through their physical body, and their body must withstand the divine energy. Barrier might be the religious caster's characteristic that represent ls their faith: willpower, the divine shield is only as strong as the character's faith in their deity.
These are just some quick and dirty examples. Nothing is set in stone even for my campaign, and I definitely will be fiddling with this concept a lot more before the group sits down to play.
I am really happy with this idea though because then even casters of the same type, who use the same skill might focus on completely different characteristics, and thus be vastly different characters, but still are able to use the same kind of magic. A Paladin might focus more on Brawn to use that Faith skill Attack spell, as well as be a big beefy soldier type, than a Priest who spends more on Willpower or whatever I set the characteristic for the Heal spell, but they both still use the same magic skill.
What do ye think? Usable? Flawed? Let me know!