Can I insert a line break in my title?

While there is not a way to force a line break within a title, you can adjust where the line splits by using non-breaking spaces.

For instance, let’s say you have the following chapter title:

In this example, SPIRIT looks odd when it appears on its own line.

To bring CHRISTMAS down to the next line, first delete the space between CHRISTMAS and SPIRIT. Then, place your cursor between those two words and hold down the Option (⌥) key as you hit the spacebar. This will insert a non-breaking space, which appears as a blue-green bucket:

Once you’ve inserted the non-breaking space, hit Return. After you’ve done this, you’ll find that CHRISTMAS and SPIRIT will stay together on the same line: