An Anti-tank guided missile (ATGM) or weapon (ATGW) is a guided missile primarily designed to hit and destroy tanks and other armoured fighting vehicles. ATGMs range in size from small shoulder-launched portable weapons, to very large vehicle- or aircraft-mounted missiles capable of defeating the heaviest tank armour.
Command guided missiles are guided manually (MCLOS) or semi-automatically (SACLOS). Guidance commands are sent to the missile through wires or radio. More advanced guidance systems rely on laser marking or a TV camera view from the nose of the missile, and some of the latest models are "fire-and-forget" and even "fire-and-fix ".
Most ATGMs have shaped-charge HEAT warheads, designed specifically for penetrating armour. Double-warhead missiles attempt to defeat very heavy or spaced vehicle armour. Top-attack weapons are designed to focus the explosion down through an AFV's thinner top armour.
Countermeasures against ATGMs include spaced , perforated, and composite armour, explosive reactive armour (ERA), jammers like the Russian Shtora, and active protection systems (APS) like Drozd and Arena.
Anti-tank weapons like Bazookas and RPGs are not considered ATGMs since they don't have any guidance system.