The Hammer Jump (ハンマージャンプ Hanmājanpu?) is a technique used by Amy Rose. It first appeared in Sonic Adventure and Sonic Adventure DX: Director's Cut and later in Sonic Advance and Sonic Advance 3. It is a whack with Amy's trademark Piko Piko Hammer that allows Amy to jump higher than usual.
When using the Hammer Jump, Amy pulls out her Piko Piko Hammer and smacks it into the ground. The force from the smash will then catapult Amy high into the air, allowing her to jump much higher than what she or any other character in the series can reach with a normal jump. When performing the hammer Jump, the Piko Piko Hammer leaves a trail of pink hearts.
Sonic Adventure/Sonic Adventure DX
In Sonic Adventure and Sonic Adventure DX, Amy could only perform the Hammer Jump by running at full speed, which was signified when the Jump button was pressed after she pulled out her Piko Piko Hammer. This made it useful for Amy when racing through the stages and overcoming obstacles.
In Sonic Advance, Amy could only perform the Hammer Jump when stationary, by pressing down on and at the same time.
Sonic Advance 3
In Sonic Advance 3, the Hammer Jump was performed the same way as in Sonic Advance. In order to perform the Hammer Jump, Amy must have Knuckles the Echidna as her partner. Amy must be the character the player controls, while Knuckles serves as the character that follows the controlled character. The move though, launches Amy at a vertical forward angle instead of directly vertical.