The Book of Memories is major plot device in Silent Hill: Book of Memories.
The protagonist receives it on their birthday from an unknown sender. Howard Blackwood, the local mailman, assures the player that the book was meant for them before he departs. The protagonist opens the book and finds that all of their memories are written in it. Curious, the protagonist decides to change some memories before falling asleep. When they awaken, they find themselves in an Otherworld-like dungeon, sent to areas that represent the guardians of people they have relationships with, pleasant or otherwise.
It is also implied that the main canon universe Michelle Valdez finds her own Book of Memories and realizes its power to change reality. Until then, she has been using the Book as nothing more than a diary.
The Book of Memories seems to have a semblance of sentience or at least a predetermined standard for regulating karmic balance. If the user is completely self-absorbed and uses the book for nothing but personal gain, all memories will be completely wiped from the pages. This means that the user can no longer freely manipulate their memories. However, the long-term effect of this phenomenon was never elaborated on.
The book has the potential to destroy the user's mind when they try to rewrite world events based on an ideal of perfection. On the other hand, if the user of the book tries to absorb all the bad karma from the people around, it can ruin their constitution to the point of being fatal.
The book also cannot be physically destroyed, as it always repairs itself regardless of the degree of damage inflicted. If the pages are ripped, they will instantly regenerate. The binding is unaffected by bladed weapons. If burned, it will re-materialize in another place nearby.
- The Book of Memories is strikingly similar to the Black Books in The Elder Scrolls V: Skyrim in that reading one will transport a user to a different universe.