The Deal With Spellbooks:
Magic is a tricky thing. It permeates all of existence, but even though it's been studied from top to what's assumed to be bottom by thousands of scholars over the years, it's still rather difficult to say with any certainty that there's anyone who actually "gets" how magic works. Part of the problem is a limitation of physiology. Regardless of how smart someone is, even if the caster has a positronic brain with zettabytes of uncompressed storage, there's still no way for anyone to actually be able to process all of what's going on when they're casting their spells. True insight into the workings of any spell is fleeting, with bits and pieces of how any particular spell works zipping in and out of any caster's perceptible mind at any point in time. When more useful observations do make their way into a caster's mind, oftentimes their instinct is to write it down, where they can later reference it to give themselves a bit of a magical edge as even the writings themselves hold some sort of arcane power, but even this comes with a few problems of its own.
First, due to the whole mystery shrouding the true nature of magic, what exactly constitutes an insight is up for debate. What a caster perceives as they pull off their finest spell-fling may seem obvious at the time, but when they take a look back at what they'd recorded in their spellbooks, a jumble of random shapes mixed with emotions, color, and the memory of seeing their crush in their underwear might not be exactly what they were hoping for. It takes a lot of practice for a spellcaster to figure out exactly what's relevant and what's not, and while written items that turn out to be useless can be later erased by the caster, usually anything that they still think might lend them that extra little oomph is left on the spell's particular page. This can make it extremely difficult for another spellcaster to try and figure out how they're supposed to use what's in a spellbook to cast a spell, without even getting started on the awful handwriting most casters have when trying to jot down fleeting flashes of random gray matter.
The most universally useful parts of any spell have been refined over the years to create magical sigils that are used to create seals, scrolls, and teach the basic parts of a spell, and these symbols are generally used to identify which spell a certain set of writings relate to. Because of this, when looking through another caster's spellbook it is easy for most casters to determine which spell they're looking at, but much harder to figure out what it all means or says. A caster who is more familiar with the spellbook's owner may be able to more efficiently weed out influences from the writer's personality and determine how the observations relate to themselves personally, but without that familiarity it can take many hours of intense scrutiny and magical experimentation to glean anything useful from another caster's spellbook.
Second, and this is a big one, as I mentioned earlier, even writing down the spell lends to itself a certain amount of mystical energy. Without some sort of magical treatment, scribing a magical sigil (or even expressing them artistically, as an Artist is wont to do) on something has a tendency to cast that spell on whatever's being inscribed. Mystics use this to their advantage, writing up their spells in advance or otherwise encoding the sigils within specially-treated paper, cooking ingredients, or previously-cheap trinkets in order to activate their spells at a whim, all the while heavily referencing their work so as not to have to recall information on the fly. Mages and similar casters, on the other hand, prefer to truly and immediately grasp the essence of a spell, and having their references be a potential magical bomb doesn't work well to their advantage. For this reason, spellbooks have been crafted using very particular magical spells and generally contain some sort of coating, weave, or mixture on or within the pages that is able to safely store the magical energy therein without it spontaneously going off. Spellbooks are probably the priciest thing that a caster will own past at the beginning of their career, but as they grow in power and hopefully wealth, the cost of new pages or more spellbooks should become relatively less.
As a quick side note, when a spellbook refers to a "page", that generally refers to a pair of pages such that both are visible when the book is opened there. For most spellbooks, only one spell is visible at a time, jotted across a two-page spread. When a mage spends their hand action using a spell book to boost their spellcasting, what they are in effect doing is flipping to the page where the next spell they are attempting to cast is (or holding it open and in front of their face, if it's the same spell they cast last turn). Therefore, a spellbook's "pages" listing refers more specifically to the number of spells it can hold.
In MSF High, Mages use spellbooks, especially the process of writing within them, as a part of the process by which they learn spells. For this reason, having a good spellbook or two is vitally important to a Mage, and there are numerous manufacturers of varying sizes that create a wide variety of spellbooks for a mage to choose between. While all a mage truly needs is a single-page spellbook upon which they can write, erase, and rewrite all of the spells they wish to learn, many mages prefer to keep a record of all they've learned handy in one or more spellbooks that they can reference while casting their spells. Since it's generally not affordable for most mages to have a spellbook large enough to accomodate every spell they've ever learned, a mage may need to swap spellbooks mid-battle. This takes a hand action seperate from the hand action they use to reference spells and gain their bonus from actually referencing the book, assuming they have the other book on hand. A preferred method of doing this is to reach into their backpack, which is linked to the same mysterious subspace as their locker, let go of the spellbook they were using, and choose to pull out another. Obviously this technique requires the mage to have prepared by placing their other spellbooks into their backpack or locker.
Because of the magics used to create spellbooks at MSF High, the things are practically indestructable. If someone is targeting one, which would be done via an accurate critical, they will find that the spellbook itself not only has 2 HP per page, but a soak of 4d12. If they manage to destroy it, it will still reappear on its owner's desk the next morning like most of their possessions. Stealing it may be a bit easier for most characters, but theft of a spellbook is considered taboo by many mages and unless the one it was just stolen from had it coming for some good reason, the thief might find themselves on the wrong end of a very angry group of mages. Vandalizing a mage's spellbook is a much more quick way of partially denying a mage access to it. If the mage is holding the spellbook, the vandal must grapple the mage successfully and spend hand actions to vandalize pages, one hand action per page starting with the spell the mage most recently cast and moving to others chosen at random each action after that. Like with destroying a spellbook, vandalized pages are restored overnight while the mage sleeps.
Spellbooks for Purchase
Most magic-centric stores will carry these spellbooks. Here are their standard prices, which differ primarily depending on the number of pages they hold. Spellbooks with more pages tend to cost more because the binding must be further magically treated to accommodate the more varied magical energies that will potentially rest within their pages.
Standard Spellbooks: These are your garden-variety, no-frills spellbooks. Relatively cheap and available in a variety of colors, styles, and page materials, these are the most commonly found spellbooks.
Elemental Spellbooks: These spellbooks are designed with flourishes showing off their element in question. When one is bought, it's chosen as a single element. Spells of that element written in that spellbook cost 10% MP less to cast, though this cannot bring a spell's MP cost below 5 MP. Spells of other elements cost 25% more MP when cast from this book, while spells of the opposing element will not work with this book--even attempting to write a spell of the opposite element will outright destroy the page it's written on.
Large-Print Spellbooks: These spellbooks have oversized pages, allowing you to place a single spell on each page, meaning that two spells can be referenced with a single turn of the page. If a mage has their spellbook set down somewhere, it can help to free their hands up for other actions. When a mage records what is in this spellbook, make sure to note which spells share pages with each other.
Binder-Style Spellbooks: These spellbooks come without any pages, rather a set of rings or other fasteners that can hold in pages. While they have a relatively higher cost for lower numbers of pages, the pages become more economical as you can simply add more in (or take out currently unneeded spells for later use) rather than buy a whole new spellbook, and pages can quickly be shuffled between binders for an action per page moved rather than having to erase and rewrite spells. A binder's cost refers to how many pages it can hold, it comes with no pages on its own, and those cost $15 apiece.
Special page properties
These properties can be applied to any of the above spellbooks' individual pages to give them more special properties. Multiple properties can be applied to a single page, though if multiple properties with a superior quality price are applied, the costs are determined as though they were multiple superior quality enhancements. A single page cannot have more than +5 worth of bonuses in this fashion.
Auralescent Ink: Pages with this property use an ink keyed to the owner's aura, rendering it invisible when not being held by the owner. This treatment costs $5 per page.
Chicken Descratch Filter: Pages with this property shift the writing on them subtly to make it more legible to others. Spells written on pages treated with this impose a far less deleterious penalty upon anyone trying to read them, reducing the -5 penalty to a mere -2. This treatment costs $10 per page.
Emergency Use Coating: These pages are coated in a reagent that, when activated by the tearing out of a page, cause the spell to cast automatically. Because of their distinct use like scrolls, the used pages do not return the next day like a vandalized or destroyed book normally would. To make a spellbook emergency use, each page requires additional ingredients with a value equal to 50% of the spell's cost, in addition to the normal cost of the spellbook itself. A spell written on a prepared page requires that the mage 50% of the spell's MP cost to cast the spell then, and then the other 50% when the spell is used in this manner. Though this is extremely pricey
Glance-Reactive Ink: These pages are receptive to special inks that fade or darken when the spell is cast depending on how much eye traffic the area received during the casting, allowing the mage to more easily assess what parts of the spell are more effective. This acts like a superior quality enhancement for the book, with the same price as a similar enhancement on a weapon or armor and each +1 granting a +1 to rolls made to cast that page's spell. The ink itself also costs money, with an additional cost of $20 for enough ink for a single spell. This must be paid again if the spell on the treated page is erased and a new spell is put there.
Mahoucite Corrugation: This paper is produced with tiny micro-folds created from mahoucite nanotubes, allowing the holder to focus magical power through the page to amplify their spells' destructive power. Once per day, a mage may raise the damage dice of any damage dealt by the spell on the treated page when it is cast by a mage holding the book in their hand by a single step, or by +1 if the damage dice are already d12s or higher. This treatment costs the equivalent of a +3 superior enhancement bonus per page, and this may not be purchased multiple times on a single page.