Using the gem and ink listed in the material components, you inscribe a unique sigil in a nonmagical book, creating a small demiplane within the pages. This sigil can only be accessed by you, and the book is magical whilst the sigil is unbroken. Breaking the sigil with a magical weapon, or an effect such as Dispel Magic, can remove the book's enchantment, but the demiplane and its contents remain in existence.

Casting this spell on another book will dispel the first book's enchantment, in favour of creating the new one. The caster can link the new book to the original demiplane by using the corresponding sigil, or create a new one- the number of which cannot exceed their intelligence modifier. Attempting to create more demiplanes than you are capable of in this way will result in the first demiplane being destroyed, and its contents being scattered into the astral plane.

The book can hold up to 250 pounds, not exceeding a volume of 32 cubic feet. Inanimate objects, excluding corpses, can be placed within this demiplane, as long as they fit through the book's open pages and do not cause the book to exceed its capacity. It takes one action to deposit or retrieve an item.

Placing the enchanted book inside an extradimensional space created by a Bag of Holding, Portable Hole, or similar item is an inherently dangerous act. Roll a d20. On a 5 or lower, both items and their contents are instantly destroyed, and a gate to the Astral Plane opens. The gate originates where the one item was placed inside the other. Any creature within 10 feet of the gate is sucked through it to a random location on the Astral Plane. The gate then closes. The gate is one-way only and can't be reopened. On a roll of 6 or higher, the book and its contents are destroyed, and creatures within 10 feet of the items take 3d10 force damage.

At Higher Levels: When cast at 4th level or higher, this spell allows you to create another Book of Storing without dispelling the first, effectively allowing you to have a number of these active at once, up to your intelligence modifier (minimum of one).