Z button

The Z Button on a GameCube controller.

The Z button refers to the long, purple button at the top right corner of a GameCube controller; the rectangular, gray trigger located on the back of a Nintendo 64 controller; or the rectangular, white button on the back of the Nunchuk. It can also collectively refer to the ZR and ZL buttons, two circular white buttons on the top of the Classic controller. ZL and ZR are also buttons on the Wii U GamePad and Wii U Pro Controller. There is no Z button on the Wii remote. On the GameCube and Classic controllers, the purpose of the Z button is to grab opponents, and holding it past the grab will shield the character. In Super Smash Bros. Melee, it's also used for grabbing items in midair. On the Nunchuk and Nintendo 64 controllers, the Z button is used to shield.

In terms of Super Smash Bros. Brawl's programming, the Z button on the GameCube controller is considered to be both a shield button and a standard attack button at the same time. This is known because nowhere in character movesets does the game check to see if a grab button has been pressed - it only checks for if a shield and an attack button have been pressed simultaneously. This explains why the Z button can execute both attack-based functions (natural combo continuations, smash charging) and shield-based functions (air dodging). This may be the case for the other two games as well.

• 

  Nintendo 64 controller's Z button.

• 

  Nunchuk's Z button.

• 

  The Classic Controller's ZL and ZR buttons.

• 

  The Wii U GamePad's ZL button.

• 

  Its ZR button.