The easiest way to keep a long novel consistent is to maintain a story bible: one central record of the characters, places, timeline, relationships, important objects and rules of your story. Then check each new chapter against it.
What should a story bible contain?
For every important character, record their full name, age, appearance, family, occupation, relationships, motivations, important possessions, secrets, speech patterns and first appearance. Small details matter: if Daniel has blue eyes in chapter two and green eyes in chapter twenty-one, readers notice.
Track who knows what. A character cannot react to information they have not learned yet. Note major revelations and the chapter in which each character becomes aware of them — especially in mysteries, thrillers, fantasy and stories with secrets.
Keep a running timeline: dates, time of day, travel time, character ages, seasons and deadlines. Timeline errors are surprisingly easy to introduce during revision because moving one chapter can affect everything after it.
Record recurring locations — where the staircase is, which direction the bedroom faces, how far the village is from the city. Readers unconsciously build maps of your world.
Fantasy and science fiction especially need rules. If magic has a cost in chapter three, it should not suddenly become free in chapter twenty.
Why AI-written books need this even more
AI models are good at producing locally convincing prose. They are not automatically perfect at remembering every fact spread across a 90,000-word manuscript.
That means AI-written and AI-assisted books benefit enormously from structured book context. A writing tool should not merely know the last few paragraphs. It should understand the book.
Story consistency in Author Magic
Author Magic builds a story bible as your book develops. It tracks characters, places, facts and the timeline, including who knows what by chapter.
It can then read the manuscript against that accumulated information and flag contradictions such as changing physical descriptions, impossible knowledge, timeline conflicts, inconsistent locations and conflicting story facts.
That context is also supplied when you ask AI to help write or revise the book, so a new scene is created with more awareness of what has already happened. Instead of maintaining a separate spreadsheet beside your manuscript, the continuity system lives with the book.
KDP's rules change from time to time. Check KDP's own help pages for the current requirements before you publish.