Reducing the humanitarian impact of the use of explosive weapons in populated areas is a key priority for the United Nations, the International Committee of the Red Cross (ICRC), civil society and an increasing number of Member States. The United Nations Secretary-General has expressly called on parties to conflict to avoid the use in populated areas of explosive weapons with wide-area effects. While the use of explosive weapons in populated areas may in some circumstances be lawful under international humanitarian law (IHL), empirical evidence reveals a foreseeable and often widespread pattern of harm to civilians, particularly from explosive weapons with wide-area effects. Many types of explosive weapons exist and are currently in use. These include air-delivered bombs, artillery projectiles, missiles and rockets, mortar bombs, and improvised explosive devices (IEDs). Some are launched from the air and others are surface launched. Whilst different technical features dictate their accuracy of delivery and explosive effect, these weapons generally create a zone of blast and fragmentation with the potential to kill, injure or damage anyone or anything within that zone. This makes their use in populated areas – such as towns, cities, markets and camps for refugees and displaced persons or other concentrations of civilians – particularly problematic. The problems increase further if the effects of the weapon extend across a wide-area either because of the scale of blast that they produce; their inaccuracy; the use of multiple munitions across an area; or a combination thereof.