Several shapes of cookie cutter function have been used in weapon effectiveness analyses. Although it is perceived that different cookie cutter shapes would lead to different analysis results, little proof has been developed. This paper investigates whether different cookie cutter shapes produce different results of Monte Carlo simulations to determine the probability of damage on area targets. Four cookie cutter shapes, which are circle, ellipse, rectangle, and the actual shape of weapon lethal zone, were employed in a case study on multiple shots of artillery weapons against a uniform value target. The Monte Carlo simulations were carried out on different number of shots, targets, and weapon lethality data. Statistical analyses were performed and it was suggested that the difference between the results determined by different shapes of cookie cutter function was statistically significant but the effect of the shapes of cookie cutter function on the results was small.