The pages of this book are filled with theoretical enigmas that intrigue legal theorists, yet oil and gas law is practical enough to satisfy the desire for "real law" shared by most second- and third-year law students. This edition contains numerous changes from the first two editions. The authors have added materials on environmental law in a new Chapter 9. They have also inserted the materials on implied covenants into Chapter 2, alongside express lease provisions, and moved the materials on royalty disputes into Chapter 3. They have updated and revised all of the chapters.