The FP-45 Liberator is a handgun manufactured by the United States military during World War II for use by resistance forces in occupied territories. The Liberator was never issued to American or other Allied troops, and there are few documented instances of the weapon being used for its intended purpose; this was compounded by the intended recipients – irregulars and resistance fighters – rarely keeping detailed records due to the inherent risks if the records were captured by the enemy. Few FP-45 pistols were distributed as intended, and most were destroyed by Allied forces after the war.

Insurgency weapons and tactics (IWAT) are weapons and tactics, most often involving firearms or explosive devices, intended for use by insurgents to engage in guerrilla warfare against an occupier, or for use by rebels against an established government. One type of insurgency weapon are "homemade" firearms made by non-professionals, such as the Błyskawica (Lightning) submachine gun produced in underground workshops by the Polish resistance movement. Another weapon that is part of the conventional military arsenal, but which has been taken up to great effect by insurgents, is the RPG. Two examples of an improvised weapon used by insurgents would be the improvised explosive devices used in Iraq and the Molotov cocktails used against vehicles and tanks. Two tactics used by many insurgents are assassinations and suicide bomb attacks. The latter tactic is used when an insurgent has a bomb strapped to them or in their car, which provides a low-tech way for insurgents to get explosives close to critical enemy targets.