This text covers all of the subjects necessary to evaluate oil and gas properties. Subjects include decline curve evaluation using both Arps' equations and more recent equations, and net cash flow calculations in a royalty/tax system and a production sharing contract. Time value of money and managerial indicators are also discussed. Resource and reserve definitions under PRMS and SEC systems including a compilation of the 1978 and 2008 SEC definitions. Oil and gas pricing is discussed including an example on calculating the revenue from a POP contract. Examples of AFE's for horizontal and vertical wells are provided along with lease operating statements. Methods of handling uncertainty are covered including sensitivity analysis, expected value tables, decision trees, and Monte Carlo simulation. There is a chapter on U.S. Federal Income Tax as applied to both IPRO and integrated oil companies. Land concepts are discussed and a technique for determining working interest and net revenue interest in complex deals is presented. One chapter covers the three styles of report - letter, formal, and oral - with specific suggestions for the report content and example reports.