Overdrives
Overview
Overdrives are Final Fantasy X’s version of Limit Breaks. They are powerful abilities and attacks that become available when their Overdrive gauge fills up. The Overdrive gauge is located under the health bar and it fills up differently depending on which Overdrive Mode is selected for each of the characters.
Overdrive Modes
They start off only knowing the “Stoic” Overdrive Mode which is very similar to how Limit Breaks behave in previous Final Fantasy games: it charges when the character is hit with an attack and takes damage. Refer to the Overdrive Mode section below for more information on the different modes that are available and how to activate each of them:
Switching your character’s Overdrive Modes to change the way that they charge and, hopefully, increase the rates at which they charge.
Overdrive Mechanics
Overdrive damage does not fall into either physical or magical attacks, so Strength and Magic weapon auto-abilities will not effect their power. This also means that Overdrive attacks will go right through an enemy’s 
Protect and Shell statuses if they have them active.
There are also four auto-abilities you can use that affect a character’s Overdrive:
Double OverdriveAeons
Each Aeon that you obtain in the game also has its own Overdrive. An Aeon’s Overdrive can only be charged when it takes damage. They can also use the “Boost” Command to charge their Overdrives much faster. Refer to the Aeons section for more information.
Overdrive List
Each character’s Overdrive is listed below:
Tidus’s Overdrive where he performs powerful sword techniques with timed button presses.
Yuna’s Overdrive that summons an Aeon with a full Overdrive gauge, ready to use its own Overdrive immediately.
Auron’s Overdrive requiring specific button combinations to execute powerful sword attacks.
Kimahri’s Overdrive that uses enemy abilities learned through the Lancet command.
Wakka’s Overdrive using a slot machine mechanic to determine the type and power of the attack.
Lulu’s Overdrive where she rapidly casts a chosen spell multiple times by rotating the analog stick.
Rikku’s Overdrive that combines two items from her inventory to create a wide variety of powerful effects.