So, based on the OP, i believe the good/evil axis was intended to map to how you have fun, while the law/chaos axis maps how closely you hold to the books.

Good wants everybody to have fun, and wont knowingly have fun at the expense of other players. Neutral only cares about their own fun, but is not willing to antagonize anybody, while evil really doesnt care how anybody else feels as long as theyre enjoying themselves.