The book is an anthology of fictitious law reports first published in Punch as Misleading Cases in which Herbert explores, as he saw it, rather absurd aspects of the law, and upholds his civil liberties with the protagonist Albert Haddock, representing Herbert's point of view, taking many to court.
Stray cases also appear in his collections of miscellaneous humorous essays, such as General Cargo.
The BBC successfully adapted them for television as three series of A P Herbert's Misleading Cases (1967, 1968 and 1971: 19 episodes in total), with Roy Dotrice as Haddock and Alastair Sim as the judge, Mr Justice Swallow who has to unravel Haddock's logic.
Being a law reform activist, Herbert, through these "Misleading Cases", aired, initiated and sustained debate on various aspects of the law in which he saw need for change: copyright, divorce, defamation, liquor licensing, the police as agents provocateurs (usually Constable Boot) and rules of the road being some of the recurrent themes.
The case is found in his favour, Haddock also suggesting to the prosecution that it is open to other authors to take the same tack as he has.