Direct-fire

Direct fire refers to the launching of a projectile directly at a target within the line-of-sight of the firer. The firing weapon must have a sighting device and an unobstructed view to the target, which means no objects or friendly units can be between it and the target. A weapon engaged in direct fire exposes itself to return fire from the target. This is in contrast to indirect fire, which refers to firing a projectile on a ballistic trajectory or delivering munitions by guided or unguided missiles. Indirect fire does not need a direct line of sight to the target because the shots are normally directed by a forward observer. As such, indirect fire weapons can shoot over obstacles or friendly units and the weapons can be concealed from counter-battery fire.

Examples of direct fire weapons include most ancient and modern weapons such as bows, handguns, rifles, machine guns, and recoilless rifles. The term is most often used in the context of artillery, such as howitzers and mortars.

Direct fire remained the dominant method of operating artillery throughout most of human history, with indirect fire used for sieges and involving specific siege guns. Technological developments born of the Industrial Revolution and the development of technical practices in the late 19th Century led to an appreciation of indirect fire, although it was not until World War I that indirect fire supplanted direct fire as the primary method by which artillery supported the other combat arms. During World War II direct fire remained secondary to indirect fire, although it was used profusely in situations where indirect fire was less effective and new direct fire artillery such as anti-tank guns and anti-aircraft guns were developed.

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