Swap Battles are featured exclusively in the Chamber of Arms and introduce several changes to the normal battles, as detailed below.
- 10-man Party: The player creates a party of ten units (in truth two parties of 5 units each). One party is the main party while the other is the reserve party. The player uses both in order to beat the Bosses. Players cannot use multiple copies of a particular unit no matter where they are stationed in.
- Unit Swap: The signature feature of Swap Battles. Player is able of swapping units from the main party with those from their reserve party. The player can do this at any time during the beginning of their turn (before performing any action) and can even swap Downed or Petrified characters to their reserve party. However incapacitated characters cannot be swapped back to the main party and are thus considered permanently removed from the battle. It should be noted however, that units who use an ability that forces them to remain stationary for several turns (like Singing buffs) are treated as "reapplying" an action, therefore no swapping can be done while said unit is active under said status.
- No Companion: The player cannot use friends for these battles so they must rely solely on their own units to succeed. As per the above rules, the player can use at most 10 different units with well distributed strengths in both parties.
- No Items: The player is not allowed to use any items, so healing of any kind (Status Ailment, HP or MP) must be done by the units themselves.