The path to the workshop and book began, for Shell, with a little piece of paper that’s been hanging above his desk for nearly a decade. It contains a handwritten list of four books that Shell knew he wanted to write. Number one on the list, a negotiation book, was realized in 1999. Bargaining for Advantage: Negotiation Strategies for Reasonable People (Viking Press/Penguin Books) [“Off the Shelf,” Nov|Dec 1999] has sold more than 120,000 copies and has been translated into 12 languages. His second planned book, on law and strategy, was published by Crown Business/Random House in 2004 as Make the Rules or Your Rivals Will. (That one didn’t do as well, and is currently out of print.)

Third on the list: a book about negotiating inside organizations.

Shell did preliminary research on internal negotiation after the release of Make the Rules, but he shelved the idea when he wasn’t satisfied with his attempts to get a handle on the subject. Soon afterward he was talking with Moussa on campus about the requests in the negotiation workshops to talk about internal negotiations.

“That kind of reminded me of the book on my list that I hadn’t crossed off yet,” Shell says over a plate of pasta after the morning of the Vayner video, “and I thought, ‘Mario is a change consultant. He works for organizations all the time,’ which I do not. And he just seemed to be the perfect person to write this book with if I was ever going to do it.” He asked Moussa if he’d like to collaborate on a book. Moussa asked if he was serious. Shell replied, “Yes. It’s a book I’ve been wanting to write.” And Moussa said, “Okay.”

Between forkfuls of pasta, Shell says, “It was the easiest idea sale I’ve ever had to make.”

It helped that Shell and Moussa already had a good working dynamic. In Woo-speak, they’d established a Trust-Level relationship. Writing a book together can be a long, arduous journey, but the two already knew each other well enough to have formed solid and positive beliefs about the other’s character, motives, and traits. Plus, Shell was dripping with credibility. He had that best-selling book behind him. He had launched Wharton’s Executive Negotiation Workshop in 1996, and his link with Wharton’s negotiation curriculum actually stretched back to its beginnings.

Shell first became interested in negotiation as a recent law-school grad working at a big firm in Boston in the early 1980s. “If you’re a lawyer, you’re a professional advocate and professional persuader,” he says. “I wasn’t that aware of the process. I was just doing it.” Still, he knew he had a strong interest in mediation, arbitration, and negotiation as alternatives to litigation.

When he decided to transition from practicing law to teaching it, he interviewed at a number of law schools. Then Wharton called. They were seeking faculty for the legal-studies department, and they’d picked up his CV. He had a business background from his law practice and they liked an article he’d written on arbitration. They offered him a job. “I realized when I lined up my options that being at Wharton meant being at the top of that particular genre, and that the law schools I was looking at were good law schools, but they weren’t the best law schools,” says Shell.

The professor’s measured analysis of the situation—the laying out of his options, the weighing of pros and cons—fits with his self-ascribed “persuasion style”: chess player. As part of the Art of Woo’s first step, the book provides diagnostic tests to help categorize yourself within one of five persuasion styles. The chess-player is described as a low-key personality who makes strategic, behind-the-scenes moves.

The real-world example that Shell and Moussa use to personify the style is John D. Rockefeller, who quietly extracted himself from an unsavory business partnership early in his career by making his partners think his leave-taking was their idea and by lining up powerful supporters to buoy him once he was released. Four others illustrate the four remaining persuasion-styles: driver (Intel CEO Andy Grove), commander (J.P. Morgan), promoter (Andrew Carnegie), and advocate (Sam Walton). These are some of the hundreds of businesspeople, politicians, screenwriters, producers, activists, religious leaders, rock stars, and military leaders whose biographies Shell, Moussa, and their research assistants pored over and transformed into case studies.

Once at Wharton, Shell’s affinity for chess playing continued to be effective. He patiently laid the groundwork to fill a void he noticed immediately in Wharton’s curriculum. There was no negotiation course. “It took me a couple years,” he says, “to come up to speed within the working community to start a course of my own.” He attended a summer program at MIT to learn how to teach negotiation from leading practitioners, including Max Bazerman and Larry Suskind. Then he collaborated with behavioral psychologists in the Decision Sciences (now Operations and Information Management) Department, who were also interested in the topic, and they developed the course together.

Read between the lines of this lead-up to Shell’s successful career at Wharton and his well-received books on negotiation and persuasion and you see a man who’s a patient, skillful, and effective social strategist. Shell arrived at Penn with the credibility cast by a BA in English from Princeton University and a JD from the University of Virginia. Learning negotiation from the masters in the field and collaborating with another Wharton department to introduce the new course were surely steps that added to the success of his venture.

Shell has used his persuasion skills behind the scenes of other projects, such as Penn’s West Philadelphia initiatives launched in the 1990s, which included helping to set up the University City business-improvement district, opening the Penn-Alexander public elementary school, providing mortgage assistance for homeowners, and investing in renovating buildings in the neighborhood surrounding campus. Shell had lived in the neighborhood since arriving in Philadelphia in 1986 with his wife, a journalist. There they raised their two sons, Ned, 18, and Ben, 25. (Shell doesn’t use Woo on his sons; he says he’s more often the object of their persuasive skills.) Shell was part of a group of University faculty and staff that put together a study for then-Penn President Judith Rodin CW’66 Hon’04 on how other universities were managing their own community relations. A typical chess player, Shell didn’t do the presenting, but he did write the report.

He was chair of the Legal Studies department when Wharton changed its curriculum in the late 1990s. Though a bit guarded about specifying how and why persuasion was necessary at this juncture, Shell points to it as a time when his theories were tested and proven. “The process of getting new curriculum through any school requires a lot of knowing when to accommodate and when to push and what to push,” he says. And of course, a professor is every day in the business of selling ideas in a way that will excite and inspire students. Shell has taught in MBA, undergraduate, and executive-education courses at Wharton, as well as in the Law School, and he has won teaching awards in all of Wharton’s degree programs, most recently for the 2007-2008 academic year.