By the Book

Meaning of Idiom ‘By the Book’

When something is done by the book it is done strictly according to the existing rules, regulations, or laws.

Want to see more videos from Idioms.Online? Subscribe to our YouTube channel!


“The detective had always done things by the book, but for this case, he had to throw the book away.”

“He doesn’t do everything by the book, but he gets results.”


Shakespeare used this phrase as early as 1597, in Romeo and Juliet. In 1:5, Juliet told Romeo, “You kiss by the book.” It can be assumed that the “book” being referred to was the Bible. This was “book of rules” that was most universal.

However, Juliet was not saying that Romeo “kissed by the rules.” Romeo had just said “Sin from thy lips? O trespass sweetly urged! Give my sin again.” Juliet referred to the Bible to say that Romeo’s kisses were not a sin. She was comparing them to something divine. (Source)

It is thought that originally, “by the book” was a reference to swearing on the Christian Bible in court. To speak by the book was to swear you were telling the truth. By the 1800’s the idiom had begun to acquire its present meaning. A common example is Edgar Allen Poe’s Murders in the Rue Morgue (1841):

“Thus to have a retentive memory, and to proceed “by the book” are points commonly regarded as the sum total of good playing.”

By this time, “the book” had come to refer metaphorically to any rulebook.

More Idioms Starting with B

More Bible Related Idioms

More Book Idioms

More By Idioms

This page contains one or more affiliate links. See full affiliate disclosure.

YouTube and Facebook Group