I love spell books. I did a video about them and everything. They are fascinating elements to magic in fantasy. Wizards are supposed to be wise. They got that way because of what they learned. None of that is cutting deals with powers, thank you very much. I am looking at you Warlocks. Books are where you store that knowledge.
The books themselves can often be dangerous. The Cthulhu mythos is a hell of lot less interesting without the Necronomicon. In the fiction, the book was written by Abdul Alhazred and originally title Al Azif. Abdul, a worshiper of elder gods, died mysteriously shortly after writing it. Al Azif was lost along the way, but not before being translated to Greek and being renamed Necronomicon. Various fragments of it floated around for centuries. The book’s arcane lore would often drive one mad if read in total, and held terrible truths about the universe. In gaming terms, not only does it hold lore, but spells oriented to that lore. The books curses those who read it with madness or the like.
With that in mind, I will present a few ideas for tomes of arcane power and lore. These are dangerous to own and read. These are books you sort of want, because of those tasty, tasty secrets, but if you are smart you will avoid.
Side note: I added some tentative game effects, curses, and the like. I also added some spell lists found in the books. Those will be of more interest in some campaigns than others, depending on how hard it is to find new spells in your campaign. This is broadly writen in 5th edition terms, but these could work in any fantasy game, with some tweaks.
The Codex Potentia
This tome was written by an unknown author, but it is widely considered blasphemous. Many faiths have tried to destroy the book, but copies have always been found. The original edition is almost certainly destroyed, and current copies were transcribed years later by various scribes. The best-known transcription was by Varisius of Galn, and he made several commentaries in the margins. Varisius himself was struck down, in his tower, by a pillar of flames which struck from the heavens and incinerated him, and his library, instantly. This was widely seen as judgement from the gods.
The Codex itself is not actually evil in nature. Instead, it is a book of detailed knowledge gleaned about gods. These are not histories or myths, but in-depth studies of their powers and nature. This is from the standpoint of scholarly arcane magicians. The clear goal was to discover how to oppose, counter, and gain divine power without actually being a priest or a divine being.
The lore involved is dangerous enough. The spells contained are tied to interactions with divine magics. They range for low-level spells which block divine magic casters from their own powers to a difficult ritual which strips power from a god directly. All of these magics are hard and have expensive components, but even their sheer existence is considered a threat to priesthoods everywhere. They might even constitute threats to the world itself if used by the wrong people.
Curse: So long as this in your character’s possession, they cannot be healed by divine spell-casters. They also are affected by Turn Undead as if they were undead.
Spells in the book
Notes: This is not a magic book for every campaign, but I have played in some campaigns where it would work quite well. As to the spells contained within it, I would need to write some spells. The first would be a spell which blocked Channel Divinity for a combat and probably would be 4th or 5th level. The grab the power of the god’s spell is more of a quest/threat in the game rather than something you use normal spell casting rules for.
The Book of Delus Moran
Delus Moran’s origins are mysterious. He claimed to be from outside the known worlds. He was a plan shifting wizard. This, of course, is not unheard of in magical circles. Travel through the planes is dangerous, but powerful mages often do it. The outer planes, however, are another story. Terrible things try to tear down the walls of reality from the outer planes. Delus Moran claimed to have explored those realms where even time and space break down.
The book, written on metal plates, details things he discovered in those regions. The names of gods long dead by the time men began walking are found here. Their slumber can be broken by speaking those names. The mathematics of those planes are found in complex formulae. It is said that if you follow those arcane formulae to their conclusion then the end of the world is shown. Beyond its terrible secrets, it has spells of use to would be planar explorers. It might be useful, but for the danger it seems to present to those who would read its adamantine plates.
The book itself may be indestructible, but it has been lost several times through the years. The last reported encounter with it was I the island community of Bromlin. The community was largely known for the small wizard’s academy on the island. The book was presented as a gift to the headmaster by adventurers who found it in a ruin. Shortly after receiving it, the headmaster apparently went mad. He began killing students and villagers indiscriminately. The school burned down and the headmaster was pulled into a dark portal. The book was lost, but will likely appear again.
Curse: Any time you read the book you have must make a Will save DC 25 or go permanently mad (see DMG on rules for madness). Also, every time it is read there is a 10% chance a Gate will open to an outer plane. It will remain pen for 24 hours and will attract the attention of beings living there.
Spells in the book
Contact Other Plane
Protection from Energy
Note: The spell list would likely need to be more robust, but these are ones I found in the SRD. This is built on the classic “Necronomicon” model. You read it, you go mad. You use it, you might get you and all your neighbors killed. It is also a great way to hook some extra-planar threat into a campaign.
The Commentaries of Balthazar
Balthazar of the True Academy was a mage with a well-earned scholarly reputation. In an order known for keeping records, his volumes were often sought after. There was one set, however, that were problematic. While Balthazar was largely considered to be a good man in life, he had an unfortunate tendency to converse with dark powers. In particular, the Fey were known to parlay with him nearly as an equal. The author disappeared mysteriously leaving a large portion of his library behind. Nothing which touches on the Fey is ever free of their influence. Nothing of their names is ever completely lost to their sight. In this way, The Commentaries of Balthazar have caused the ruin of many.
The Commentaries are in a simple leather-bound codex. Within are the observations, illustrations, and revelation which the scholar discovered over the centuries. It is warded from scrying and is not easily found. There are a few spells described, as well as many other things. Encrypted in the text are the true names of powerful Fey Lords and Ladies. In the centuries since its writing, the book has been sought out by those with an interest Fairie business. A few warlocks have even used it to strike deals to gain their power.
The book is never destroyed, though a few have tried. Instead, through seeming coincidence and chance it is eventually lost. A zealous priest bent on destroying it will accidentally fall into their own pyre. A librarian will misfile it and it will reappear a century later as a young scholar is perusing the stacks. If its secrets are discovered, power will follow, but so will a fall. The Fey always have the final trick.
Curse: The reader’s name is immediately known by Fey Lords. You immediately attract their attention. As long as you possess the book, you are disadvantages to avoid detection. When you read the book, you must make a DC 15 Wisdom save or a Contact Other Plane will be cast contacting a Fey Lord or Lady. The rest of the effects of that spell are the same, including the results of failure.
Spells in the Book
Glyph of Warding
Notes: It is hard to convey how the Fey are just inherently dangerous unless you have read the right things. This is dangerous to read book like the others, but with a Fairie theme to it.
These are just a few books I came up with. I may do another post of books that are less dangerous to read.