Numbers only, titles only, or both. All three are standard, and published fiction is split almost evenly between them.
Rather than issue a rule, the Chicago Manual of Style's editors went and counted. Across fourteen New York Times bestselling fiction titles:
"4 novels used chapter (or part) numbers but no titles, 4 novels used chapter titles but no numbers, 6 novels combined numbers and titles for parts and chapters."
Their conclusion: "there is a choice, even within traditional publishing".
So this is a genuine decision rather than a convention you can get wrong.
What Each One Does
Numbers only is the fiction default and the most invisible option. A number makes no promise and gives nothing away. It says only "this is where you are", which for a novel driven by momentum is usually all you want.
Titles only works where chapters are strongly distinguished from one another, most obviously when they alternate between viewpoints or timelines. The Chicago editors note the practical benefit: titles "may provide more helpful clues to [a passage's] location than chapter numbers", particularly where "chapters alternate between their points of view".
Both is the most common in the sample, six of fourteen, and is the standard treatment when a book also has parts. It gives you the navigation of a title and the ordinal certainty of a number.
New Hart's Rules adds the genre tendency: chapters "often, especially in non-fiction, [have] a title". So titles are more expected outside fiction, which is worth knowing if you are writing memoir or narrative non-fiction.
The Two Warnings
Both from the Chicago editors, and both easy to violate:
"Think twice about including essential information in the chapter title."
"Avoid spoilers."
A chapter titled "The Funeral" has told the reader someone dies before they read a word of it. Titles sit in the table of contents, so they are readable out of order and in advance, which is exactly the property that makes them useful for navigation and dangerous for suspense.
This is the strongest argument for numbers in a book that depends on surprise. A thriller with descriptive chapter titles has published its own outline.
Two Mechanical Rules
"Chapter numbers are rarely followed by a period unless a chapter title follows." So 1 and Chapter One take no full stop, but 1. The Drowned Meadow does.
"Don't end chapter titles with a period." Headings do not take terminal punctuation, though a question mark or exclamation mark is fine where the title genuinely is one.
There is also a consistency requirement from New Hart's Rules: if the word "Chapter" appears in the contents list, "it should also appear at the head of each chapter in the text". The contents page and the chapter openings have to match.
Does It Change Whether You Need a Contents Page
Yes, and this is the practical consequence people miss. Quoting Chicago 1.38: "a table of contents may be omitted for books without chapter or other divisions." The editors add:
"In hardcover and paperback novels a table of contents is of limited value compared to a TOC for nonfiction, especially when a book has only chapter numbers, not titles."
A contents page listing "1, 2, 3, 4" tells a reader nothing. One listing chapter titles is a genuine navigation aid. So titling your chapters is also a decision to have a useful contents page.
Note this applies to print. An ebook needs a navigation document regardless, as covered in do novels have a table of contents.
What Deckle Does
Both elements are independent settings, so all three treatments are available without workarounds.
Chapter numbering has five formats, Arabic, spelled out, Roman, uppercase, or hidden, plus a separate toggle for the word "Chapter". Setting numbering to hidden gives you titles only.
The document title is the chapter title. Naming a chapter in the Binder is what puts a title on it, and there is a separate control for whether that title displays, so a chapter can carry a working name you use for navigation without it appearing in the book. That is genuinely useful during drafting: "Ch 9 fix the timeline" can be your Binder label without reaching print.
The generated table of contents is built from these settings, so it cannot drift from what the chapter openings show.
For the numbering conventions themselves, see how to number chapters in a novel.
Common Mistakes
- Assuming one is correct. Bestsellers split roughly evenly across all three.
- Titles that spoil. They appear in the contents, readable before and out of order.
- A full stop after a bare chapter number. Only used when a title follows.
- A full stop at the end of a title. Advised against.
- Contents and chapter heads disagreeing. If one says "Chapter", both must.
- A contents page of bare numbers. It gives the reader nothing.
FAQ
Q: Should my chapters have titles? A: Entirely optional. Bestselling fiction splits about evenly between numbers, titles, and both.
Q: When are titles most useful? A: When chapters alternate between viewpoints or timelines, where they help a reader relocate a passage.
Q: Why avoid descriptive titles? A: They sit in the contents page, so they are read in advance and can spoil the book.
Q: Do numbered chapters need a contents page? A: In print, rarely. Chicago notes a contents page of bare numbers is of limited value.
Q: Can I use titles in the Binder but not in the book? A: Yes. The display of a chapter title is separate from the document's name.