Infinite Dimensional Cape

The Infinite Dimensional Cape is a technique in Super Smash Bros. Brawl wherein Meta Knight is able to exploit his Dimensional Cape to remain impervious for extended periods of time. When using this move, Meta Knight is invisible, and cannot be harmed, as all attacks simply pass through his hitbox undetected. -By repeatedly and very quickly using the upward smash attack while simultaneously holding down on the control stick, Meta Knight can remain in flux for as long as the technique can be properly maintained, which can be quite difficult. He can also move left and right, but must remain primarily on the ground to sustain the IDC.

The GameCube and Classic controllers are able to execute the maneuver with standard controls by using the C-stick or right analog stick for upward attacks. It is also possible with the Nun chuck by converting a button into an upward smash. Unfortunately, the Wii Remote cannot be used to perform the IDC, as the upward smash attack can only be assigned to the 'up' direction, and as the technique would require pressing two opposing directions on the pad ('up' and 'down') at the same time; a hardware impossibility.

Of course, the potential effectiveness of this move is astounding for defense and offense alike, allowing evasion of virtually any kind of attack, while stealthily transporting to attack opponents (a nearly perfect approach). For these reasons, and due to the stalling capabilities of this technique, the glitch has been banned by the Smash Back Room for use in certified tournament play.

When Meta Knight exits the infinite maneuver, he will most likely attack, and may be open to punishment if not used carefully, and at low percentages, the lag on the attack can be punished whether or not the hit connects. Should Meta Knight fall off an edge while using this technique, he will become helpless and unable to grab the edge, just as he would when using a normal Dimensional Cape.

References

Video showing technique

In depth explanation of the technique