From Longman Dictionary of Contemporary Englishby the bookby the bookOBEYexactly according to rules or instructions She feels she has to go by the book and can’t use her creativity.do/play something by the book The police were careful to do everything by the book. → book
Examples from the Corpus
do/play something by the book• He plays it by the book.• I do it by the book.• They play it by the book - their book not mine. 