The X button refers to the grey, cashew-shaped button on the right side of the GameCube controller, the small, white button towards the top right of the Classic Controller, the top button of the Nintendo 3DS, Wii U GamePad, and Wii U Pro Controller, and the top dark gray on both the Nintendo Switch's Joy-Con and Pro Controller. It is used for jumping while fighting. In Super Smash Bros. Melee, Brawl, and Smash 4, it also changes the palette swap on the character selection screen. The Nintendo 64 controller, Wii Remote, and Nunchuk do not have a X button. It also appears on the Wii U GamePad and Nintendo 3DS for both installations of Super Smash Bros. 4. When using Joy-Con (R) as a single Joy-Con held horizontally, the X button will become the right button, acting like an A button and performing standard attacks.