Alchemy, Artifice, and Magecraft operate much like SotC's Gadgets or Artifacts. Each potion, item, or spell is made up of one or more effects -- the magical equivalent of improvements. These effects for these three forms of magic are as follows, with the appropriate form of magic in parentheses afterwards. Most are just like their SotC counterparts, but there are a few new ones in there, too.
Additional Capability (Artifice)
The item can now do something else of roughly the same scope. Examples include a magical bow that fires arrows of pure energy, a flying cart that can travel on the ground or through the air, or a sword with a blade of fire.
Alternate Usage (Artifice, Magecraft)
This effect allows skills to be used differently. Examples include enchanted spectacles that allow the wearer to use Alertness rather than Empathy to get a read on someone, a magical bolt that allows the caster to attack using Art rather than Missile, or a spell of speed that allows the target to use Art (or the caster's Art) to cover ground instead of Athletics.
Armed (Alchemy, Artifice, Magecraft)
The imbiber, item, caster, or target gains the ability to attack, or to allow its possessor to attack, with Melee or Missile as if he/it possessed a weapon of some kind. Examples include a scarf that can be used as a whip, a potion that imbues the wearer's hands with supernatural hardness, or a spell that creates a sword of fire.
Armored (Alchemy, Artifice, Magecraft)
The imbiber, item, caster or target is granted or provides armor-like protection. If taken once, this effect provides the benefits of Light Armor. If taken twice, it acts as Medium Armor, and three times, Heavy Armor. Examples include a potion that hardens the subject's skin, a cloak that provides magical protection against blows, or a spell that sheathes the target in abjurant energy.
Aspect (Alchemy, Artifice, Magecraft)
Add an Aspect to the target. Depending on the other effects of the spell, this can be so fragile as to only last for the space of a single exchange, sticky enough to last for hours, or anything in between. This effect can be taken more than once to increase the "stickiness" of the Aspect, but again, the base duration will depend on the spell. For example, "Aspect: Flying" on a spell of magical flight would last as long as the spell (one scene) and "Aspect: Prone" lasts until the target gets up, whereas "Aspect: On Fire" granted via an instantaneous spell like firebolt would last much longer than the spell itself, though the target could take actions (e.g., some combination of stopping, dropping, and rolling) to remove it.
The device has some manner of sentience and is able to act independently in a very limited fashion. Oftentimes, this means that the item gains a skill, the rating of which is equal to the total number of effects the item possesses. This effect can be taken multiple times to either bump up a single skill or acquire new ones. How this all shakes out depends greatly on the item in question, but odds are only mental skills will be appropriate. For example, a sword containing the bound spirit of a demon might have its own Alertness skill, or Lore, of which the wielder can make use. Athletics, however, would be a tough sell, because the sword simply lacks a means of locomotion. Despite the sentience, the item can't act independently of its owner; it requires a command or prompt of some kind to activate. Note that this basic concept can also be more or less created using Upgrade, below, although it'll be quite different in practice.
Like Conscious, but the device is capable of basic reasoning, and can interpret simple commands. As the name implies, the item can act independently, even if its owner is unconscious. Limited movement is possible, even without a means of locomotion, as is speech or some other form of communication with its bearer. Depending on the nature of the item, it can even have physical skills such as Melee, although these will always be limited to Mediocre (in other words, having the skill at Mediocre lets the item use it at all).
Delay (Alchemy, Magecraft)
Technically, this isn't an effect on the item, spell, or potion, but on one or more of its existing effects. For example, a Delayed shocking blast explodes a few minutes after the mage casts it instead of immediately. The mage decides the length of the Delay when he casts the spell.
Trigger (Alchemy, Artifice, Magecraft)
Like Delay, Trigger postpones the effect(s) of a spell, item, or potion, but unlike Delay, the determinant isn't time, but a specific event or contigency. If you want to get pedantic, nearly every product of Alchemy has a trigger: drinking the potion, applying the oil, etc. But that sort of thing doesn't count as an effect; this is different. You can consume a feather-weight potion now, but it won't activate until you experience a sudden fall. That's the Trigger. Similarly, the shocking blast above could be cast with a Trigger of "When someone opens this door."
Duration (Alchemy, Magecraft)
This effect increases the default duration of the potion or spell. A potion that would normally last for an encounter can be made to last for several hours or all day; likewise, the same can be done with a spell that has a base duration of longer than one exchange (thus, no day-long shocking blasts). Some spells have a duration equal to the caster's Art skill in rounds. Applying this effect to those spells doubles, triples, etc. the duration, depending on how many times the effect is applied.
This is the "It's much bigger on the inside!" effect -- something that looks small, but which behaves as if it weren't. Examples include a pouch that holds as much as a warehouse, a dagger that does as much damage as a greatsword, or a hut that can sleep a small army.
The inverse of Miniaturization: Sometimes you just need something to be big. This effect is used to alter an item for circumstances when size will truly matter, such as a weapon that can’t possibly damage its intended mega-monster target without being very large, or a house-sized carriage pulled by dozens of horses that’s able to transport a huge number of passengers.
This effect extends the range of a spell from touch to one zone, from one zone to two, etc. Each application of the effect extends the range by one increment.
This effect increases the number of targets the spell can affect. Spells default to one target; with one application of this effect, the spell either affects two targets or a number of targets equal to the caster's Art -2, whichever is greater. Two applications of this effect makes the spell affect an entire zone.
Craftsmanship (Alchemy, Artifice, Magecraft)
The device gives a +1 bonus to any effort using it (usually only to one skill, if the device or potion supports the use of multiple skills). This improvement may not be taken more than once per affected skill. Examples include a magically sharp sword, an amulet that imparts arcane knowledge to its wearer, or a potion (or spell) of strength.
The item has 2 extra boxes of stress capacity over the default, which is usually 3. May be taken multiple times.
Special Effect (Artifice)
The item may now operate on different principles, like a carriage that doesn't need horses or a mace that can strike ghosts as easily as the living. The game benefit of this will depend highly on the specifics.
Upgrade (Alchemy, Artifice, Magecraft)
Upgrade has a lot in common with Craftsmanship, but instead of applying a +1 bonus to the entire scope of a skill, Upgrade grants +2 to a specific usage of it. A troll-slaying sword, for example, might get a +2 when used against trolls. A potion of fae friendship could impart a +2 to Rapport when speaking with elves, and a spell of assessment would give the caster a +2 to Lore only for the purposes of learning the past history or nature of a magical item.
Here's how it works. Let's take a spell of magical flight. It basically does two things: it lets you use magic to move, and it lets you move in an unusual way.
Effects (2): Alternate Usage (Magic instead of Athletics to cover ground), Special Effect (Flying)
Duration: 1 scene
Compare that to a spell that lets the caster beat a hasty retreat using more conventional means:
Effects (1): Alternate Usage (Magic instead of Athletics to cover ground)
Duration: 1 scene
A spell's default duration and range depend on the type of effect being created. Attack spells default to one exchange. Ranged spells default to a range of 2 zones (and a single target); everything else is touch.
Some more examples of spells:
Effects (1): Alternate Usage (Art instead of Missile)
Duration: 1 exchange
Range: 2 zones
Effects (3): Alternate Usage (Art instead of Missile), Scope x 2 (1 Zone)
Duration: 1 exchange
Range: 2 zones
Effects (1): Alternate Usage (Magic instead of Rapport)
Duration: 1 scene
There are still some things to sort out here, like what skill gets Alchemy, and I'm planning on fairly extensive lists of spells and potions. I want to make sure GMs and players know they can make up their own, but it's important for the setting that there be codified spells that are taught to budding mages. I think of it as chemistry. Yes, you can figure out on your own what sulfuric acid is and how to make it yourself, but you'd be crazy not to learn the conventional way to do so as well.
And I'm renaming Magecraft to something else, but I'm not sure what yet. Thoughts?