How to pull a Willy (and get away with it) is a book written by Willy that can be found in the back room at Willy's House.

This is the First draft of Willy's Willy-pulling seminar. In order to pull a Willy on someone you need to a) always have the upper hand and b) a firm grasp of the situation. To squeeze every bit of gold or other valuables out of an individual you need to lay a subtle trap. A Willy trap. Run up to your victim out of nowhere and proceed to give the individual you are facing the feeling that you're offering the best bargain of the year. The Willy way consists of making a deal that one can't refuse. After the Willy trap comes the Willy pull; the moment when one actually pulls off the Willy. Never give the victim the idea that you are swindling him, never look him straight in the eye and never ever take no for an answer! Once you've pulled off the Willy, run as fast as you can and don't look back. Master this technique and there will be no person you can't pull a Willy on.

– How to pull a Willy (and get away with it), Divinity II: Flames of Vengeance