 Devil Summoner was the first Megami Tensei title to be released on a 32-bit fifth-generation home video game console, and the first Megami Tensei game to feature 3D graphics. The latter presented a new challenge for the development team: while they found adjusting to the new specifications a challenge, they also greatly enjoyed working with the Sega Saturn, the which was unlike anything previously experienced by the team. Among the design staff were Katsura Hashino, who focused on combat, and Shogo Isogai, who focused on coordination between gameplay events. The demon conversation system was conceived by Okada based on experiences with the multiple accents encountered in the Kansai region of Japan. Using this as a base, he created the response system to give demon negotiation a more realistic feeling than previous Megami Tensei games. It was also a means of equalizing the relationship between demons and the player party, which had previously been more akin to master and servant than equal partners. The Zoma demons, which could be freely tailored into different demon types, was created while the team was balancing out the game's difficulty. The gameplay difficulty, which by later standards would be considered quite high, was toned down from the difficulty of earlier Megami Tensei titles to appeal to a wider audience. This necessitated balancing a more forgiving difficulty with keeping traditional Megami Tensei gameplay elements.
