The next day's Magic Theory class covers magic resistance, penetration, and Arcane Connections. Alidade begins the lesson with a demonstration, using a handful of weak magical artifacts* on several volunteers. Alexius participates, demonstrating his high level of Corpus resistance by putting on a headband of cat ears without any felinification occurring. ("As this is a Muto Corpus effect with an Animal requisite, expertise in Animal would also provide some resistance.")

*Suspiciously, most of them seem like they would be useful in pranks.

Creatures of the four magical realms - divine, infernal, faerie, and magical - also tend to have some degree of magic resistance proportional to their power. 

Magic resistance can be overcome by sufficiently well-cast spells or effects. There are many ways of improving a spell's power, including those from the last lesson, but the specific practice of using tools and techniques to overcome resistance is called Penetration. Practice in this area is always useful at bypassing resistance, but it becomes much more effective when a mage has access to sympathetic or arcane connections to the target.

To use the theory of Penetration, a mage needs an Arcane Connection. This is usually a physical object (or in some cases, place) that has some tangible relation to the target: belongings, created works, body parts, or in the case of magi themselves, familiars and talismans. Arcane Connections remain mystically linked to their source for anywhere from hours to decades, or indefinitely if the magical link is "fixed", a process that typically involves months of intensive lab work. The closer the relation (e.g. belongings are a weaker connection than body parts) the longer a link lasts without being fixed, and the more effect a skilled mage can get when using it to overcome magic resistance.

A mage with an Arcane Connection can also use other sympathetic magic to further boost Penetration. Sympathetic connections include:

- Being a blood relative of the target
- Something the target has signed
- The target's nickname or birth name
- The name the target uses in secret magic rituals, if different from the above
- An accurate horoscope for the target (more effective if you know and can use their birthday)
- A well-crafted symbolic representation of the target, such as a sculpture or painting

Some spells have a range of "Arcane Connection", meaning they can only be used if the caster possesses an Arcane Connection to the target. But an Arcane Connection can be used in almost any spell. 

Alidade sketches out a few examples of rituals and casting methods that involve sympathetic magic; they are considerably more complex than the alternative. "The field is complex enough to have its own formal courses in the advanced magic track for apprentices; for aspiring magi who wish to learn the details, I recommend signing up with Magus Oliator in the winter."

Alex listens carefully and takes notes. Could he use this to target the woman attacking his village? She probably isn't actually named Clarisse but maybe more information about her will come out at trial? He doesn't actually know if there's any way to get that information though.

If he wanted to target her, he would need a physical Arcane Connection of some kind. A possession or item of clothing, a lock of hair, or similar.

During the discussion of Arcane Connections, it comes up that the Petronian Orders keep a vial of blood belonging to apprentices who are Opened to the Arts, and that it and other potential connections can be requisitioned by the Order of Justice to aid in the censure of errant magi (or, it goes unsaid but strongly implied, to execute traitors.)

Right, knowledge letting him get through her arcane resistance is a nice consolation prize though.

The class wraps up with an assignment to derive one's own daily horoscope (for discussing in the afternoon session) and nativity horoscope (a longer-term project expected to take multiple hours). Astronomy is heavily involved. 

That's relatively straightforward. It's interesting that so many things are connected to the position of the stars and planets when someone is born. It suggests something is very magically powerful about beginnings. Or maybe that people are somehow less malleable over time. Or hmm... maybe it isn't all about exactly when you're born but something to do with the pattern that sets up for your early life somehow.

His work proves adequate for the afternoon class, which explores how horoscopes are used in ritual magic and where other sympathetic connections slot in. Alex gets the sense the lessons only scratch the surface, there, but at least he'll have more of a feel for it after today.