This open access book presents the evaluation of undiscovered oil and gas resources and reserves growth in 468 basins around the world, as well as the potential of unconventional recoverable resources of seven types, including shale oil, heavy oil, oil sands, oil shale, shale gas, coalbed methane, and tight gas. The evaluation methods used are innovative, incorporating both conventional and unconventional oil and gas resources evaluation methods that utilize plays as the fundamental evaluation unit based on various exploration maturity levels. The evaluation results obtained independent intellectual property rights and provide an overview of the future exploration potential and prospects of different regions. It is a valuable reference for researchers, practitioners, and students involved in petroleum exploration.