Perhaps you remember the job class systems that were avaliable in Final Fantasy Tactics and Final Fantasy V. Dresspheres are a lot like traditional Final Fantasy job classes, yet, have a very unique an interesting take on the old school idea. With a dressphere, one of the girls can instantly change into a new job class and get an all new set of abilities to use against their foes in battle.
Sound simple? For the most part it is. When you begin the game, you'll start out with a few basic dresspheres - The gunner, thief, warrior, and songstress. Even though it might not seem like much, you can gather up over a dozen dresspheres during the course of the game. These can be found by completing certain missions. Before you know it, your girls will be able to transform into everything from a White Mage to a cute Moogle. (Using the Mascot dressphere!)
There is a catch, though. You'll not be able to use all the dressphere's abilities when you first obtain it. Each of the girls will have to use it in battle. When they do, they'll gain AP, which can be used to unlock new abilities in the dressphere. Even if one girl unlocks an ability in a particular dressphere, the other two will also have to do it. This can be a bit time consuming, but it's more than worth it!
Dresspheres can be used by equipping them to a Garment Grid. Once you equip them and assign grids to the girls, they'll be ready to go, able to instantly transform between dresspheres in battle.
There are also unique dresspheres known as Special Dresspheres. Each girl gets one and are unique to the character. In order to use the special dressphere, you'll need to use ALL of the dresspheres on the garment grid, and then press the R1 Button. Doing this, you'll see all the dresspheres have been activated and you'll be able to choose their special dressphere.
Enough talk: Let's get to the dresspheres, shall we? Just choose a dressphere below that you want to learn more about.