A preface is written by the author, about the book as a book: why it exists, what it covers, who it is for, and how it was made. It is not about the subject matter, which is what an introduction is for, and it is not a recommendation from a third party, which is what a foreword is.
It should be short. Yale University Press sets the only hard number any authority gives: not more than two printed pages.
The Definition, and the Length Rule
Yale's guidance is the fullest statement of what a preface is, and it is worth quoting at length because it is unusually specific:
"The preface is neither an integral part of the text nor a vehicle for exposition or lengthy discussion. It should not require more than two printed pages (three manuscript pages). It is entirely different from a foreword or an introduction and cannot replace or be replaced by either."
"The preface is about the book as a book, not about the subject matter. It informs readers and reviewers of the aims and purposes of the book and the audience for whom it is intended. Since many reviewers base some of their comments on the preface and often quote from it directly, it is particularly important to provide a summary of the need for, and outlook of, the book in a way that will enable them to use suitable passages in their reviews."
That second paragraph is the practical insight most authors miss. Reviewers quote the preface. It is, in effect, the pitch, and writing it as an afterthought wastes the one place you get to frame your own book.
New Hart's Rules gives the same definition more briefly: "The preface is the section where the author sets out the purpose, scope, and content of the book."
What Goes In It
Yale lists what a preface should cover:
- Why the book is needed and how it differs from others
- Its scope and treatment
- What function it performs
- Which groups of readers it is for
- The method of research, editorial method, or organisational scheme
And on tone: "emphasize the constructive and creative ideas presented and avoid self-criticism. Deliberate omissions of relevant material should be pointed out, but not apologetically."
That last point is worth internalising. A preface that apologises for what the book is not tells a reviewer exactly which weakness to lead with.
Brief thanks can go here rather than in a separate section. New Hart's Rules: "In the absence of a full acknowledgements section, the author may include in the preface brief thanks to colleagues, advisers, or others who have helped in the creation of the work." Yale agrees, adding that anything longer should become its own section. See how to write acknowledgements for a book.
The Variants
New Hart's Rules sets out the forms a preface can take, and they are more varied than people expect:
- Editor's preface, in a multi-author work, written by the volume's editor.
- Series editor's preface, identical across every book in a series, preceding each author's own.
- Edition prefaces, one per edition, each titled accordingly.
When earlier prefaces are reprinted in a new edition, they follow the current one in reverse order:
"Preface to the paperback edition Preface to the second edition Preface to the first edition"
Each preface conventionally begins on a fresh right-hand page, "unless reasons of economy dictate otherwise."
Signing It
Optional. Yale: "The preface need not be signed." The Chicago Manual of Style's Q&A notes that "prefaces are often signed at the end", and where two co-authors each contribute one, advises putting the byline at the top instead and listing both in the contents as "Preface, by Author A" and "Preface, by Author B".
This is the mirror of the foreword rule: a foreword must carry a name because someone else wrote it; a preface may carry one because you did.
Does a Novel Need One
Usually not. The preface is a non-fiction instrument, explaining a book's aims and method to readers and reviewers. A novel's aims are the novel.
Where novels do carry one, it is generally an edition preface, written years later for a reissue, explaining what the book was and what has changed since. That is a legitimate and common use.
If what you want to write is story, you want a prologue, which is a different thing in a different part of the book.
What Deckle Does
Deckle has a Preface document type in the Front Matter menu, alongside Title Page, Copyright, Dedication, Epigraph, Foreword and Table of Contents. It starts with a placeholder, "Begin the preface here."
As front matter it takes lower-case roman numerals when restart numbering at Chapter One is on, and it appears in a generated table of contents.
If you need more than one preface, for a second edition or a series, create a separate document for each and title them explicitly ("Preface to the Second Edition"), ordering them in the Binder newest first to match the convention above. Export order follows Binder order, so the sequence you see is the sequence you get.
For the distinction from its neighbours, see prologue vs preface vs foreword.
Common Mistakes
- Writing about the subject rather than the book. That is an introduction.
- Running past two pages. Yale's cap, and a good discipline regardless.
- Apologising in it. Reviewers quote prefaces, and they will quote that.
- Calling it a foreword. A foreword is by someone else.
- Burying the thanks in it when they run long. Long thanks become their own section.
- Adding one to a novel out of habit. Most novels do not need it.
FAQ
Q: How long should a preface be? A: Yale says no more than two printed pages, which is about three manuscript pages.
Q: Preface or introduction? A: Preface if it is about making the book. Introduction if it begins the argument.
Q: Should I sign it? A: Optional. Yale says it need not be signed; Chicago notes many are.
Q: Can there be more than one? A: Yes, for successive editions or a series, listed newest first.
Q: Is the preface part of the text? A: No. It is front matter, in roman numerals, and Yale calls it "neither an integral part of the text" nor a vehicle for discussion.