This paper considers salvo-firing situations where the cumulative damage contribution is unimportant and presents some approximate probability expressions of an analytical nature. These results are valid if the target size and vulnerability are not too large compared to the round dispersion, and the other assumptions adopted are those ordinarily used for problems of this type. These expressions show that, for the two-dimensional situations considered, a salvo kill probability can be approximately stated as an explicit function of four parameters. These parameters are the number of ammunition rounds, the average target vulnerability times the target size, the salvo aiming error dispersion, and a function of the round dispersion and two dispersion type terms which depend on the target size, shape, and vulnerability. Thus the target properties are condensed into three numbers. Also the resulting probability expressions are of a form which permits direct examination of the effects of changes in the salvo-aiming system (fire-control system), the number and properties of the ammunition rounds, and the properties of the target. Operations Research, ISSN 0030-364X, was published as Journal of the Operations Research Society of America from 1952 to 1955 under ISSN 0096-3984.