<p>Product ratings are so important that sellers need to focus on rating rules, i.e., how ratings are calculated by e-commerce platforms. However, limited studies have examined the impact of these rules on the review system design. Using programming codes, we simulate consumers’ online shopping activities and the functioning of the review system. Through an indicator system, we compare the performance of the dynamic rating rule, which displays the mean of recent ratings in one rating cycle, and the traditional rating rule, which displays the average of all posted ratings. Results show that the dynamic rating rule always performs better on competition fairness. This rule also usually displays higher values of ratings and diminishes the disconfirmation effect, although it generates a lower number of reviews. Interestingly, these results may be reversed for search products. This study offers guidance to e-commerce platforms on how to manipulate the review system by adapting rating rules.</p>