Books of Magic

The various grimoires, tomes, and books of arcane spells possessed by wizards from all parts of the globe are more than just the repository of their acquired magical knowledge, they are (often) in fact living beings whom the possessing wizard is deeply dependent upon. Not all spell books are sentient, however, yet nearly all those that provide spells over third level (D&D5E) have some form of otherworldly intelligence. Further, it is not required that the intelligent spell book have the same alignment as its user, only that they symbiotically feed off each other. For it seems the spell book is tied to the very life force of the caster, and the "outer being" that comprises its essence feeds off the energy pulsing through the caster's body. In return, it grants the caster its arcane wisdom, even going so far as to speak with the caster telepathically, opening up their neural pathways to the necessary extent in order to filter through more powerful arcane spells. It is even hypothesized that there is an unseen and undetectable "element" that transfers from the spell book entity to the possessing caster. This hypothetical "mana" is often referred to as "flux," or sometimes "the miasma," as it manifests itself as a clouding of the wizards vision, visible as a dulling of the eye. Though this assumed element cannot be seen, it's effects on the caster are often visible. Some even propose that this miasma is what grants the wizard their ability to perform magical feats. Once this element is "spent," it fades from the caster's body and mind until later replenished through study of the "living words" within their arcane tomes.

Acquiring A Living Tome

Sometimes a tome is wholly alive, fully imbued with the life force of some being from beyond the veil. Other times, but a few pages (or even a single page) carries the same life force. In this manner, books can be "found" either fully possessed, or they can even begin as "normal" tomes that eventually fall under control of a symbiote over time. The outer life force can be almost thought of as a transmittable disease, in that it can "infect" an innocuous tome through tainted ink used to inscribe new spells, or even other means. Often wizards of greater power wishing to rid themselves of their symbiotic entities attempt to transfer them to their acolytes or hedge wizards through use of tainted ink. Sometimes they simply "gift" the spell book in question to an apprentice. Either way, the only manner in which one can rid themselves of a symbiote, once attached, is through transference to a new host. Some wizards have learned how to "pull" their symbiotes into the magical ink used to transcribe spells, and thus can transfer it to an unwitting caster's own tome, while they think they are simply gaining a new spell. So, it is unfortunately common that a caster may not known that he or she has inherited an alien intelligence intent on fusing its will to their own... until, of course, it's too late.

In Game

How is this power represented in gaming terms? Normally, it isn't, as the standard give-and-take is already present through the use of spell slots in Dungeons and Dragons. However, there might be a way to "push" this relationship between symbiote and caster. Perhaps if a mage were to force his or her mind to accept more "flux," thus granting additional spell slots, the outer being associated with it gains more control over them, body and soul. As this is a work in progress, I am still determining game effects, but this could be represented by a Charisma Save that increases in difficulty each time the caster pushes themselves to attain an additional spell slot. The level of the slot could set the initial Difficulty Condition, and the frequency of attempted usages could increase it from there. Perhaps the additional spell slot is only gained if the saving throw is successful. But what happens when an outer mind, one likely not wholly benevolent, gains purchase over that of the mortal wizard? Where's the fun in answering that question myself? I'm certain one can think of many devious things a symbiotic alien might desire on the material plane...