EXP Zero

EXP Zero (EXPゼロ), also dubbed as Zero EXP, is an ability introduced in Kingdom Hearts II Final Mix. It prevents the player from gaining EXP for as long as it is equipped.

This ability allows the player to complete the game without gaining EXP, and therefore staying at level 1, resulting in a more challenging play-through.

Mechanics
In Kingdom Hearts Final Mix, EXP Zero is a combat ability that requires 0 AP to equip. EXP Zero offers some benefits in that it allows Sora to deal acceptable damage against bosses despite being level 1. He also cannot be defeated in one hit so long as he is at full health, giving him an ability similar to Second Chance

In Kingdom Hearts II Final Mix, EXP Zero is a that requires 1 AP to equip.

In Kingdom Hearts Birth by Sleep, Zero EXP is a that can be equipped once.

In Kingdom Hearts 3D: Dream Drop Distance, EXP Zero is a that can be equipped once.

Kingdom Hearts Final Mix

 * Sora has EXP Zero initially in Final Mix: Proud Mode difficulty.

Kingdom Hearts II Final Mix

 * Roxas learns EXP Zero at the beginning of the Third Day in Critical Mode.
 * The Winner's Proof has EXP Zero as its Equipment Ability.

Kingdom Hearts Birth by Sleep

 * Zero EXP is attached to Terra's Sliding Dash, Ventus's Aero, and Aqua's Blizzard at the beginning of their stories in Critical Mode.

Kingdom Hearts 3D: Dream Drop Distance

 * Sora and Riku have EXP Zero initially in Proud Mode and Critical Mode.