The ceiling glitch is a glitch in Super Smash Bros. Melee that causes a character knocked upward to get hit by an invisible "ceiling", causing them to be "stage spikeed" downward.
How to perform
The ceiling glitch occurs when one performs a ground move, then another player immediately performs a move that cancels it out. The player who attacked first will be sent on the second attack's trajectory, but when they are knocked high enough, they will hit an invisible "ceiling" that causes them to plummet downwards.