Necronomicon

Wondrous item, artifact (requires attunement)

This monstrous-looking tome bound in humanoid skin has an almost palpable aura of dread. A grotesque and ghoulish face is stretched across its loathsome cover.

The Necronomicon is replete with fantastic legends of elder magic and abhorrent secrets from beyond. Its author, a mad poet-philosopher, is said to have been seized by an invisible monster in broad daylight and devoured in front of a large number of horrorstricken witnesses. Throughout unknown centuries, the Necronomicon was rigidly suppressed by civil authorities and by all branches of organized ecclesiasticism. Reading this dreaded tome always leads to terrible consequences.

Among its hideous contents, the Necronomicon details abstract formulae on the properties of space and the linkage of dimensions both known and unknown. It describes the presence of forbidden cults among human beings who serve elder, primordial races and who worship unseen entities with alien-tongued names such as Yog-Sothoth and Cthulhu.

Despite centuries of repression, a handful of copies of this horrible artifact still exist. Each one is a closely guarded secret of its owner, and not all the owners are human or even humanoid.

To reap the “benefits” of the Necronomicon, a creature must become attuned to it and then spend another 19 hours reading and studying its blasphemous text. The creature can then add to and copy the book’s contents, provided any additions advance the cause of chaos or evil and expand upon the lore already inside. (Because of this, no two copies of the Necronomicon are identical, and no one knows what has been added to or excised from the original text.)

When a non-evil creature becomes attuned to the Necronomicon, it must make a successful DC 18 Charisma saving throw, or its alignment changes to neutral evil.

Unseen forces of evil will pursue any owner of the book, hoping to steal it for themselves or for a more powerful master. Once every three days while a creature is attuned to the book, it has a 19 percent chance to encounter or be attacked by a mythos entity or occult adversary of the GM’s choosing. If a creature dies while attuned to the book, a Great Old One claims its soul, and it can’t be restored to life by any means.

Random Properties. The Necronomicon has the following random properties:

• 2 minor beneficial properties
• 1 major beneficial property
• 1 minor detrimental property
• 2 major detrimental properties

Adjusted Ability Scores. After a creature spends the requisite amount of time reading and studying the book, its Intelligence score increases by 2, to a maximum of 24, and its Wisdom score decreases by 2, to a minimum of 3. The book can’t adjust the same creature’s ability scores more than once.

Abstract Formulae. The Necronomicon contains a multitude of mind-shattering evil magic, including all mythos spells and Void spells in this section, all standard necromancy spells, and any additional spells of the GM’s design or choosing.

Eldritch Magic. Once a creature has read and studied the book, any spell slot it expends to cast an arcane spell counts as a spell slot one level higher when determining the spell’s effect.

Eldritch Lore. The book’s bearer can reference the Necronomicon whenever it makes an Intelligence check to recall information about any aspect of evil or secrets of the multidimensional universe, such as lore about Great Old Ones or the properties of disquieting technology. When doing so, the proficiency bonus for that check is doubled.

Eldritch Guise. While a creature carries the Necronomicon and is attuned to it, the creature can speak, read, and write Void Speech, and it can cast semblance of dread (described above) as a bonus action.

Voidmarked. After a creature spends the requisite amount of time reading and studying the book, it acquires mental and physical disfigurements as hideous signs of its devotion to the Great Old Ones. The creature gains one flesh warp and one form of indefinite madness. The voidmark grants you advantage on Persuasion checks made to interact with aberrations and on Intimidation checks made to interact with non-aberrations.

Thought Control. A creature that is attuned to the book and holding it can use an action to cast dominate monster on a creature within range (save DC 18). This property can’t be used again for 19 hours.

Destroying the Book

Pages can be torn from the Necronomicon, but any eldritch lore contained on those pages finds its way back into the book eventually, usually when a new author or translator adds pages to the tome. It is rumored that the Necronomicon can’t be destroyed as long as a spawn of the Great Old One Azathoth exists in the multiverse. A short-term solution exists, however: casting the book into the fire of a dying star scorches all the writing and imagery from its pages and renders the book useless for 6d6 + 6 years.