Multiple player slot glitch

The multiple player slot glitch (popularly known as the Ice Climbers glitch and the amiibo glitch in Smash Wii U only) is a glitch in Super Smash Bros. for Wii U and Super Smash Bros. Ultimate. The glitch allows for multiple player slots to be controlled by a single controller, creating an effect similar to the Ice Climbers.

Overview
In normal play, a given controller can only be controlling one player slot (such as P1, P2, etc.). Through an oversight on the character select screen, this glitch allows a controller to control multiple different player slots. The result of this is that several "players" in a match can perform the same input at exactly the same time, due to registering inputs from the same controller. They otherwise are completely independent from each other.

The glitch can be performed in any mode that allows amiibo Figure Players: Smash, Special Smash, or 8-Player Smash. It can be performed for several controllers, allowing different sets of player slots to be controlled by different controllers. Team Battles can also be played under the glitch's effects, allowing players to prevent their controlled player slots from hitting each other, similarly to the Ice Climbers.

While performing the glitch, the player can make the character-selection cursors overlap by moving them to the edge of the screen, and in a battle, they can overlap the characters by rolling to the edge of the stage. This can lead to some interesting effects with moves such as Luigi's Super Jump Punch.

Despite the removal in Ultimate, this glitch returns with the addition of patch 3.0.0. However, this method only works in Stage Builder test mode, and the instructions for this glitch is different.

Requirements

 * One amiibo that is set up as a Figure Player for Smash 4. Multiple are required for each additional player to be controlled, calculated as number of player slots controlled subtracted by one (e.g. controlling 8 slots would require 7 amiibo). The character is irrelevant as they will later be removed. The same amiibo cannot be used twice per player.
 * The Wii U GamePad.
 * An additional controller is recommended as the glitch can be very tedious with the GamePad alone.

Steps

 * 1) Enter into the character select screen in a mode that allows scanning of amiibo as Figure Players. This can be Smash, Special Smash, or 8-Player Smash.
 * 2) Using the controller of choice, enter as a player.
 * 3) Toggle that player slot until it is set to "None".
 * 4) Disconnect the controller. (For the Wii U Gamepad, simply walk out of the console's range.)
 * 5) Scan an amiibo, which will enter a Figure Player over the slot that was just occupied.
 * 6) Repeat steps 2 to 5 for as many player slots are desired to be controlled by that controller, minus one.
 * 7) Enter the Rules screen, and then exit it.

After performing these steps, the controller used will be controlling all player slots that it occupied. This can be performed with multiple controllers, allowing the different controllers to control different sets of player slots.

How to perform in Ultimate
A variation of the glitch is present in Ultimate, but cannot be used in actual versus matches and only works with 2 characters.

Requirements

 * Differently from Smash 4, this glitch does not require an amiibo. However, it requires two full controllers (the game won't allow players to enter stage builder using a horizontal joycon) to perform this glitch, can only be done in docked mode (therefore, cannot be done with a Switch Lite) and can only be done in Stage Builder.

Steps

 * 1) Create or select any stage using the first controller.
 * 2) Select test stage once the stage meets certain criteria.
 * 3) Change the fighter from a CPU to a second player, then start when ready.
 * 4) Exit the editor, save and quit back to the stage menu using the second controller.
 * 5) While using the second controller, select any stage and test the stage.

After executing the glitch, the second controller should control the first player in the stage.

Explanation
When a controller is disconnected on the character select screen, this normally leaves that player slot present, but open so that the next controller to enter will occupy it. However, when the controller is disconnected while the slot is set to "None", it is possible to scan an amiibo Figure Player to occupy that slot, which does not clear the game's impression that there is still a controller tied to the slot. After re-entering the character select screen by exiting the Rules screen, the game refreshes the state of the player slots, and links the controller to the slots that were occupied by the Figure Players, because they were still flagged as having a controller tied to them.

In Ultimate, it no longer happens as disconnected controllers will remove the player slot even if the controller is occupied by the amiibo, rendering incapable of performing the glitch.