Artillery rockets of medium and long range are used on the battlefield for indirect firing of distant targets. Having a large dispersion of hits, they are used for targeting surface areas from multitube launchers. At the same time, the line of sight of the target does not exist, so the firing elements are taken based on the known geographical coordinates of the target and the launcher, using the ballistic computer and firing tables. Long ranges, low initial velocity and long duration of the flight to the target make such rockets very sensitive to the impact of disturbances on the accuracy of hitting. As the range increases, the accuracy of rocket systems decreases more and more. At the same time, for effective coverage of the target area, a large number of rockets is counted. Firing a target area with a large number of rockets involves a statistical approach to determining the efficiency of the firing. Thereby, statistical indicators of the distribution of impact points are used, such as the circular error probable, which represents the radius of the circle that contains half of all hits. In addition to the number of rockets with which an area is targeted, the probability of destroying all targets in the area also depends on the radius of the lethal effect of the warheads. This paper presents determination of the probability of hitting and destroying a surface target.