Warren Buffet's four Rules

Warren's investing theories have been talked about ad nauseum by almost every business/finance writer and is a cottage industry all by itself.
But one he finds closest to reflecting his views is a book written by Larry Cunningham - 'The Essays of Warren Buffett - Lessons for Corporate America' is required reading in a one of a kind course start at the University of Missouri School of Business.
The course is called Investment Strategies of Warren Buffett. It turns up Buffett is hot on campus too.
The Buffett playbook is taught, analysed and written about but it is best summed up like this.

Number one - Don't lose the money
Number two - don't forget rule number 1!
Number three - look for unique companies that are hard to replicate - he calls that a moat around the business.
Number four - he talks about the circle of competence, which means in simple English, do what you know.