This fourth edition of A Guide to Mine Action has been prepared by the Geneva International Centre for Humanitarian Demining as an overview for the diplomat, donor, lawyer, practitioner or scholar on the key aspects of mine action. It takes into account key developments of the last few years, particularly the Anti-Personnel Mine Ban Convention 2009 Cartagena Summit on a Mine-Free World and the entry into force of Protocol V to the Convention on Certain Conventional Weapons. The relevance of explosive remnants of war (ERW), both at the diplomatic and field-level, is reflected in the content of the Guide.