While I'm sure that the magic system for Elemental is well along its way to being developed, I'd like to share a bit of a snapshot of all of the different ways that a magus in ars magica can have their magic differentiated from the magic of others so folks who are beta testing might have an idea vast scope of different ways that magician characters who use the same set of rules could conceivably differ from one another. I don't want to (necessarily) convey specific ideas regarding how to set characters apart, but ratter inspire folks to come up with good suggestions when it comes time for testing because I don't think that you can ever have too many choices in this role-playing-esque aspect of the game.
I'm just going to describe "Hermetic" magic characters in Ars Magica (nothing at all to do with real word hermeticism, thank goodness) there are lots and lots of different magic systems but this is the one that matters to the players.
Also before I start listing ways for characters to differ I need to describe that there are two sorts of spells used by the Hermetics (OK that's a gross oversimplification but I want to inspire not bore): formulaic magic which is spells that the character studies and learns and spontaneous magic whereby the characters can try to cast any spell they imagine whenever they choose. However spontaneous magic is difficult to cast and takes a great deal out of the caster. Formulaic magic can be on average about three times as powerful as spontaneous magic but it is of course significantly less flexible.
Ok here we go (this is all rife with oversimplification as well but I can't imagine why you'd care)
Magic abilities learned "In the field"
characters in Ars magica go on adventures like in any other role playing game but the sort of abilities they improve on adventures are a subset of total abilities (In ars you don't get abilities in a "leveling" sort of manner)
Magic resistance
Penetrating the magic resistance of others
Finesse the ability to control your magic with precision, targeting things with spells, getting your spells off quickly, the craftsmanship of things that are crafted out of raw materials by use of your magic and so on
Concentration this isn't exclusively a magic ability but it does come into play when you are trying to cast a spell with something else on your mind, like maintaining concentration on another spell or casting two spells at once or casting a spell when you've been punched in the gut and so on
Mastering the formulaic spells that you know getting better at a specific spell that you know and learning to use it better, cast it faster, cast it without using voice and gestures, cast it at longer range and so on.
Magic Power gained in the Library
Certainly people can write books on anything but in ars there are a few magical traits that are primarily improved from studying the writings of others
Magic Theory this is the ability that aids in the creation of new formulaic spells, creating magic devices and doing everything that is done in the laboratory
Magic Arts these supply the horsepower that your magic runs on. Whenever you cast a spell or invent a spell or do pretty much anything involving magic (aside from using an enchanted device) your arts come into play. There are fifteen magic arts in the game (for hermetic magic) these describe the character's power within an area. For example, there is an art that concerns animals so whenever you cast a spell dealing with animals your character uses this art score. However what differentiates these arts from things like the books of life magic in MoM similar set ups is that five of the arts are verbs and ten of the arts ore nouns. All magic uses at least one verb and one noun. Thus if one wants to create a pack of wolves the magician uses their animal score and their creation score. This means that describing a character's fifteen arts gives their relative abilities in fifty (5*10) different areas. A character who has a strong score in the destruction verb but a weak score in the investigate verb might not be able to devise and learn a spell to read a persons mind but they may be able to create a spell to destroy a person's ability to tell a lie.
Magic Activities Performed in the Laboratory
Inventing formulaic spells this can be dome either by inventing the spells from scratch or from deciphering the laboratory notes of another magician.
Creating enchanted devices this can be dome either by inventing the spells from scratch or from deciphering the laboratory notes of another magician (or referring to your old notes if you've created an item of this description previously)
Crafting or improving their talisman a talisman is a magic device that is tied to the caster, by enchanting effects in it they can gain bonuses to using magic in specific instances, for example a character who has a talisman with a ruby in it can attune themselves to gain a bonus with spells dealing with fire by attuning themselves with the ruby.
Binding a familiar or refining the bond with their familiar a familiar is a magical animal with which the magician has a magical bond. this bond can have magical effects enchanted into it that target either the familiar or the magician (such as transforming the magician into a cat, telepathically communicating between them or letting the familiar breathe fire and so on. The bond also gives each some of the strengths (and personality traits of the other) so that depending upon the strengths of the specific parts of the bond the caster can be more resistant to mental domination or less likely to botch up a magical effect and so on.
Creating a longevity ritual
Modifying the laboratory Laboratories with enchanted devices to clean and keep themselves organized are safer magical laboratories full of a menagerie of animals give bonuses to animal based activities, laboratories with impressively outfitted workbenches have bonuses to enchanting devices and so on.
Teaching your apprentice
Extracting magical resources from your surroundings
Fixing arcane connections an arcane connection is an object mystically linked to some other object having an arcane connection to a target allows the caster to cast spells on teat target from anyplace on earth and to more easily penetrate any magic resistance that the target has.
So clearly a character who spends more time in the laboratory will look much different than one who spends more of their time in the library who will in turn be much different than one who spends all of their time “adventuring”. Added to this, you have the factor that different skill levels in the magical arts (reread that section on magical arts again if you’re not following) which make for drastically different characters and then of course there are the actual formulaic spells and enchanted devices that character has acquired. So the amount of diversity here is mind boggling, two fire mages don’t have to have to have similar sets of abilities at all. But if you’ve got your wrapped around all of these ways to differentiate the magical abilities of a character you’re still only half way done.
Virtues and Flaws
Characters in Ars Magica are in great part mechanically defined by their virtues and flaws. All characters start out with a collection and it is possible to acquire more through play. Lots of these virtues and flaws don’t concern magic ability (keen eyesight, fear of cheese, cursed to be unable to sleep under a roof and so on) but I will try and give a picture of the scope of the ones that do.
Virtues and flaws that affect learning being able to absorb more material from reading books, being bad at learning from experimentation, having an affinity for learning a particular magical art or skill more quickly or gaining insight in a particular ability while studying a different field (such as gaining a few bonus experience points in fire magic from studying water magic)
Virtues and flaws that give bonuses and penalties in specific circumstances gaining bonuses when dealing with a particular subject such as ravens or ageing, having penalties or bonuses when in specific circumstances such as in direct sunlight or in a church, specific Achilles’ heel style weaknesses in one’s magical defenses, an inability to affect certain targets with your magic (such as birds), weaknesses with one or more of the arts, inability to use certain arts together (such as being unable to cast spells that control earth).
Virtues and flaws that change how you can do magic such as tying ones life force to their casting so that they can cast more powerful spells by suffering more exhaustion or wounds, Being able to cast spells by singing and so on
Virtues and flaws that expand the scope of magic Within the rules there are certain predefined ranges durations and targets to define spell effects and using something different is extremely difficult for most characters. For instance: some of the ranges used are touch, range of the caster’s voice, and sight, some of the durations are momentary, as long as the caster concentrates, until the next sunrise or sunset, until the full moon and the new moon have both crossed the sky, and some of the targets are individual, room, structure, within an inscribed circle and so on. This gives characters a serviceable set of tools fro creating spells but some virtues give new collections of ranges durations and targets for instance Faerie magic gives the range road that allows the caster’s magic to reach any target on the same road as he is on, the Durations, Bargain (the spell takes affect when the target breaks an agreement with the caster, until where the spell lasts until a circumstance has come to pass, and year and a day, and it gives the target bloodline. Holy magic gives a similar set of options (duration grace; as long as the character remains in a state of grace, duration fast; until the target eats). Sensory magic gives a set of targets based on people or animals sensing an object (anyone who feels this object, anyone who smells this gorgonzola, anyone who sees my face and so on). There are lots of these sorts of parameter sets.
So that sort of sums up a vastly simplified scheme of how magical abilities can vary within Hermetic magic (there are lots of different magical traditions) in Ars Magica. I’m hoping that it will inspire the creation of at least one more “axis” of variation within Elemental because you can’t have too many ways to fiddle with your chaneller.