The Bestia have their own developable status values

With Final Fantasy X, there was a fundamental renewal of the summon magic from the previous games in the series. While in earlier games, the called creature performed only one action and then disappeared, the Bestia called invocation creatures remain for the entire duration of the battle or until they are recalled or defeated by the enemy Cosplay NZ
. The Bestia have their own, developable status values, spells, abilities, commandos, and ecstasy. They not only support the player with strong attacks, but can also be used as a protection against particularly difficult opponents, since the opponent must first defeat the Bestia before he can harm the group. The player gets five Bestia in the course of the game, three additional can be obtained optionally by sidequests.

Originally it was planned to let the opponents move freely on the playing field, to create a seamless transition to the fighting and to give the player the opportunity to move around the battlefield. Director of Fights Shintaro Takai has stated that it was his intention to present the battles in Final Fantasy X as a natural part of the story rather than as independent elements Bakemonogatari
. Due to the hardware and limitations in the system, these ideas, later called the Active Dimension Battle System (ADB), were used in Final Fantasy XI and Final Fantasy XII. Instead of the ADB there was a compromise so that in some battles, mainly in boss battles, a motion-blur effect created a relatively seamless transition from playing field to battlefield. The desire for seamless transition also led to the implementation of the new calling system in the game.

The character development system of Final Fantasy X, the Sphärobrett, is unique in the genre of the Rollenspiele. The characters do not get predicted status and skill bonuses after a certain number of levels, as usual, but gain so-called spheres by collecting enough Ability Points (AP) after defeating opponents. These spherical levels, in turn, allow the player to move the character on the spheroid, which is a predetermined grid of several connected fields that provide different status and skill bonuses. Objects, called spheroids (obtained by defeating opponents, treasure chests, and certain events) are used in these fields, thus releasing their function for the selected character. In this way the development of the playable characters resembles a board game.

Producer Yoshinori Kitase explained that the Sphärobrett is intended to give the player an interactive way to increase the character traits and allows the player to experience the change of these qualities immediately. The Sphärobrett also allows the player to customize the characters individually, in contrast to their intended combat roles, so that the Whitemage Yuna can become a strong fighter or from the swordsman Auron a healer. In the International and PAL versions of the game, there is an optional version of the Sphere Burette Bakuman
. In this variant, all characters start in the middle of the spherical burette and the players can immediately hit any path with them, but the Sphärobrett has much fewer fields, which means that fewer status values are possible.