Regime transitions provide a rare opportunity for political actors to create or convert the process of selecting political power. On institutional choices at such a juncture rational choice approaches have been dominant. This article wants to bring up to the front historical preconditions that shape and constrain incentives in such a rational choice. I examine the case of the 13th National Assembly Elections in Korea in 1988. Previous studies, including Brady and Mo(1992) in particular, show that the choice of electoral institutions at that time was mostly based on the ruling party’s rational calculations, which was especially influenced by the just prior presidential election results. This study accepts many of findings by those previous studies. However, by considering some historically constraining preconditions, including the type of preceding authoritarian regime among others, and further examining contextual factors, this article adds importance of some other factors and emphasizes the role of conditions that critically affected the direction of strategic choices by political actors of the time.