Path of The Scorpion
A book owned by Magrat Garlick in Witches Abroad. The book was authored by the famous Ankh-Morpork ninja Grand Master Lobsang Dibbler- who lives in Ankh-Morpork, a somewhat unlikely seat of cosmic wisdom. Of course, the techniques listed (hitting people with rice flails, twisting an opponent's elbow through 360 degrees, and shouting 'Hai' very loudly) should not be used in aggression - otherwise it would be impossible to discover one's true place in the cosmos. In later chapters, it is hinted, one can learn how to chop bricks in half with your bare hands and walk on red-hot coals, and other cosmic things.
Unfortunately, the citizens of Lancre look down on cosmic wisdom, on the basis that it doesn't get the sheep sheared or the privy dug. The chrysanthemum-patterned headband only makes people enquire whether you've hit your head, and the central tenet of using your opponent's strength against himself results in vague ponderings on the likelihood of imposed self-harm.
This highly mysterious and, above all, cosmic work can be purchased quite cheaply in Ankh-Morpork, and should not be confused with the History Monks, the Yen Buddhists and other sects found in Enlightenment country