This joint OHCHR-UNODC resource book explores international law sources relevant to the use of force and the general responsibility of law enforcement authorities for the use of force. It discusses a number of instruments of force, including firearms, and the conditions under which these should be used. It further examines the possible use of force in a number of specific policing situations. Finally, it also outlines good practices for accountability in the use of force and firearms by law enforcement officials. The publication aims to support States in their efforts to develop and implement more effective, accountable and human rights-based law enforcement policies. It is intended for policy and law-makers in particular, including those involved in the drafting of policies, regulations, Standard Operating Procedures and training materials on the use of force and firearms, as well as for stakeholders exercising control and oversight functions over law enforcement agencies.