* Path/Book Magic
This is the most common form of magic in-setting, because anyone can use it: You don't need any advantages to make it work, just skill and rituals. You do need Magery 0 to have other advantages that relate to it, such as Path/Book Adept or the Magery Talent (though you can have a Gadget made by someone else that grants Path/Book Adept without needing Magery 0); fortunately, Magery and related advantages are Learnable. This type of magic is one way that a character might develop powers without being Reawakened, and is a way that some of the past lives
did get their powers: Apart from using the Fetish ritual to create a Gadget, frequent use of any specific ritual greatly increases the probability that a critical success will result in the caster gaining a magic-based power that works roughly like that ritual (if you have the points for it, or are willing and permitted to go into point debt).
The Gizmos advantage could be useful to pull out just the right charm for the job, or at least something close enough to work.
Path/Book Adept is relatively common among high-level mages and highly-skilled specialists, mostly with limitations of some sort (Aspected, One Path Only or One Book Only, Moon-phase limited, part of a Gadget, granted by a Familiar, and so on). In the absence of Path/Book Adept, it is common for adventuring Path/Book magicians to take a Rules Exemption perk removing the limit of having only one charm of a given type on one's person.
A few of the more common Path styles refer to the Paths as 'Colleges,' and have between twelve and twenty-three of them. Generally, use the Colleges of the standard spell system, but treat it as an Energy Accumulating Path style in which the energy cost for a ritual is equal to (spell's prerequisite count + 2). The Enchant spell is replaced by the Fetish ritual.
Symbolic Path/Book Magic uses the skills from Symbol Drawing Magic, with most of the system from Path/Book Magic: You still have Time, Ritual Space, and Material and Symbolic Components, but the symbolic components tend to be Symbol Tokens or related items, the core skill is Symbol Drawing, and the rituals (in Effect Shaping) default from the lowest skill with the Symbols involved. In Energy Accumulating styles, the skill roll is still that of the lowest Symbol. The use of this set of styles with Path/Book Adept generally involves drawing the symbols in the air with a finger or handheld implement, though with practice, one might do this with one's tongue.
Ritual Alchemy is Path/Book Magic that uses Alchemy or Herb Lore as the core skill. Most forms of Ritual Alchemy do not allow Path/Book Adept (Material), even if the other forms of PBA are available - you
must have appropriate material components to use it. The one exception to this is Alchemy (
Neidan), or Chinese internal alchemy.
Ritual Path Magic as written may exist in this setting if the GM wishes, but I suggest that it should be rare if it exists at all. Styles that work similarly, or that have some or all of the same Paths, might be more common.
There is no default critical failure table for Path/Book magic, although the Illusory Magic Table (Thaumatology p258) is oddly common, despite Path/Book magic not being all that illusory compared to other forms.
* Spirit Magic
This could be described as Magic As Allies, in that rather than doing the magic yourself, you have one or more spirit Allies who perform it. Generally, the spirits will have Magic As Powers. A Spirit-Magician with a lot of Allies might have them as a Modular Abilities advantage, like so: Allied Spirits (Cosmic Modular Abilities; Magic, -10%; Only for Allies with Summonable and Minion, -50%; Requires <Attribute> Roll, -10%) 1 [3]. The variants in
'Spirit Magic' as a psi ability could work in this setting, as long as the power limitation is switched out for something like 'Magic, -10%' or 'Spirits, -10%.' Ghostdancer did a helpful chart for ally/familiar/dependent costs
in his blog (scroll down a little), which I highly recommend. Spirit Allies with Minion may be thought-forms created by the magician (see 'The Tulpa,' GURPS Horror p81). These tend to be less powerful than other spirits (even other sorts of spiritual Minions), or more limited in other ways.
Assisting Spirits (Thaumatology pp90-94) also falls into this, though instead of the spell-based system, the caster has a Spirit-Assisted version of Path/Book Magic or Magic as Powers (but generally not Realm Magic); it shares the same risks as the Spirit-Assisted Magic in that section.
The default critical failure table for most Spirit magic is of course the Spirit-Oriented Magic Table (Thaumatology p260), though depending on the type of spirits one normally contracts with, other tables are plausible.