Rankings locate individual actors in different ordinal positions even though there are little differences between the actors. Leveraging positional discrepancies created by rankings, I conducted regression discontinuity analyses to investigate whether and how positional discrepancies impact competitive actions in organizational dyads. The empirical analysis of market entries of Korean conglomerates suggests that upward competition is more likely than downward competition when initiating competitive actions: organizations are more likely to enter markets occupied by higher-ranked competitors. However, the results also show that this tendency can be reversed as organizations respond to previous interactions with lower-ranked competitors. Downward competition is strengthened when the lower-ranked competitor previously initiated competition. Upward competition can be weakened by previous acquisition deals in the organizational dyad. This study contributes to research on the impacts of social hierarchies on competitive actions.