Harassing fire is a form of psychological warfare in which an enemy force is subjected to random, unpredictable and intermittent small-arms or artillery fire over an extended period of time (usually at night and times of low conflict intensity) in an effort to undermine morale, increase the enemy's stress levels and deny them the opportunity for sleep, rest and resupply. This lowers the enemy's overall readiness and fighting ability, acting as a force multiplier for the harassing force.