The Y button refers to the grey, kidney-shaped button on the right side of the GameCube controller or the small, white button on the right side of the Classic controller. Like the X button, it is used for jumping for the all games of the Smash Bros. series (including Super Smash Bros. for Virtual Console). It also appears on the Wii U GamePad, Wii U Pro Controller, and Nintendo 3DS for both installations of Super Smash Bros. 4.