Otherworldly Patron: The Library

Your patron is not a fiend who demands sacrifice from you for you power, nor is it a hag who has given you power in return for assisting her rituals or collecting her ingredients. Your patron is only known as The Library. The Library is a being of nearly endless knowledge and curiosity. It was formed by the collective knowledge of the world bound in shelves and bindings, and by the residual magics of the most powerful wizards and sages, who recorded their arcane findings on pages and in tomes. The Library is neither outwardly benevolent nor malevolent, being very orderly and neutral in its actions. The Library does not seek out creatures to complete its goals, rather, it tests those that have promise in securing dangerous artifacts and maintaining order. The warlocks that make The Library their patron are known as Librarians, and are often scholars or sages in practice. Dungeon Masters who have a player with the Library Patron are encouraged to have their warlocks seek and secure powerful artifacts, and any Librarian who abuses said artifacts should be punished accordingly.

Intellectual Spellcasting

The nature of your patron changes the very nature of being a warlock. Your spellcasting ability is changed from Charisma to Intelligence, so you use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use you Intelligence modifier when setting the saving throw DC for a warlock spell you cast and when making an attack roll with one, and all warlock features that use your Charisma score/modifier for the feature instead your Intelligence sore/modifier.

Spell save DC = 8 + your proficiency bonus + your Intelligence modifier

Spell attack modifier = your proficiency bonus + your Intelligence modifier

You also gain the ability to cast warlock spells as rituals:

You can cast a warlock spell as a ritual if that spell has the ritual tag.

Library Book

At first level, The Library has gifted you a book to take on your journeys. Though this book, you maintain a connection to your patron, as well as the knowledge it contains. The book will automatically record information that it detects around it and gives you abilities while it is in your possession. You are also given permission to enter The Library

• You are bonded to your book. You can summon it to yourself as a bonus action if it is on the same plane of existence, causing it to teleport instantly to your hand.
• Your Library Book can serve as an spellcasting focus, for the purpose of casting your warlock spells.
• You can read your book to accurately recall anything you have seen or heard while you have had it in your possession.
• You can perceive though the book, reading it in your minds eye as it transcribes what is around it. You can use this ability regardless of the books location. Darkness does not effect the books perception. 
• While holding the book open in your hand, you gain proficiency in 1 of: Arcana, History, Nature, or Religion. Additionally, you can change your Library Book's proficiency(ies) of your at the end of a long rest, bookmarking different sections of your book for different wells of The Library's information. The number of proficiencies increases with your warlock levels; you gain 2 proficiencies at 6th level, 3 at 10th level, and all 4 at 14th level.

When you gain your Pact Boon at 3rd level, if you take the Pact of the Tome, your Library Book doubles as your Book of Shadows, gaining triangular gold plates on the corners of the binding of your book. If you loose your Book of Shadows, you may use either form of regaining it, provided by the Pact Boon or by the Library Book feature.

Expanded Spell List

The Library lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Library Expanded Spells

SPELL LEVEL	SPELLS
1st	Detect Magic, Identify
2nd	See Invisibility, Zone of Truth
3rd	Blink, Water Walk
4th	Locate Creature, Secret Chest
5th	Mislead, Telekinesis

Body of Knowledge

At 6th level, as an action while holding your book, your body merges with it. While merged;

• You become Tiny and appear to be a simple book, although anyone that can see magic will see it as Divination.
• Your speed is reduced to 0
• You automatically succeed in any check to hide, assuming that the creature didn't see you merge and has no reason to suspect the book.
• You can only communicate telepathically with any creature you can see within 30 feet of you, seen in the creatures mind as writing of their own language. They cannot reply telepathically.
• You can use your action only to remove yourself from the book, cast a touch-range spell, or perform a Paper Cut attack, dealing 1d4+Int slashing damage to anything holding you. 
• When you choose to leave the book, you can decide to instead come out of the pages of any other book within 60 feet of you. 

You can use this feature a number of times equal to your intelligence modifier (minimum of 1) plus your proficiency bonus . You regain any expended uses when you finish a short or long rest.

While taking a long rest, you can use this feature to visit the Library in your dreams, allowing you to research. You are unable to focus on the outside world unless you are shaken from your research, and if you are shaken from your research you are only able to perceive anything within 30 feet of the book.

Knowledge is Power

At 10th level you gain the ability to take one other creature with you when you merge with your book. You both perceive this as standing in an infinite room filled with floating text. If you focus on the nearest text, you see it describing that you are reading it in real time. If the creature is not hostile, it gains all the abilities that you do when merged with your book, with the added ability that you can communicate clearly with each other and have seemingly physical forms. If the creature is hostile, both yours and the creatures attacks do psychic damage and use the Int modifier instead of any usual proficiency. The book bounces comically on the floor while a fight is occurring in its pages. If you or another creature dies while in the book, they are expelled from its pages, unconscious. You can use this feature a number of times equal to half of your Intelligence modifier (a minimum of once). You regain any expended uses when you finish a long rest.

At 14th level, the number of creatures you can take with you increases to two.

Knowledge is Eternal

At 14th level, you have built up a powerful connection to your patron through your book. 

• Any creature you defeat in the pages of your book, you can chose to have your patron possess them. The creature is charmed by you until a Dispel Magic spell is cast on it, it dies, or you use this feature again. It will follow all basic direction given to it by you even if it risks its own life, and answer any questions to the best of its abilities. 
• If you are reduced reduced to 0 hit-points, your book absorbs you to save you from death. If you fail your death saving throws within your book, you remain inside the book until you can be revived, or until you are returned to The Library. While inside your book, you are incapacitated, but not unconscious. Should your book be destroyed while you are inside it and have 0 hit-points, you are ejected from your book and you die. If you return to The Library after you have died in your book, you are returned to 1 hit-point,.
• As an action, you or a creature that holds your book can create a gate to The Library temporarily, where the only component is to use an entrance to any library. This new gate is closed once the entrance door is closed.
• You may also use The Library to travel to other libraries from the one you entered. Once per long rest, you can choose a library that you have previously visited in a 100-mile radius of the library that you entered as the previous gate, and use its entrance as the new gate out of The Library.