Ledge-canceling (also known as edge cancelling) is an advanced technique in Melee that allows players to end the landing lag from an aerial attack (and some special moves) by sliding into their teetering animation after landing or by sliding off of the stage or platform entirely. Ledge-canceling moves grants players both opportunities for more movement options and for extremely fast followups using attacks that do not normally have combo potential. While all aerial attacks can be ledge-canceled, not all aerial special attacks can be. Attempting to cancel one of these specials will usually result in the character remaining on the stage for the rest of the lag of the attack. Some special moves, like Link's Spin Attack can be ledge-canceled without ever leaving the ground simply by running at the edge and performing the special move with good timing.
In Super Smash Bros. Brawl and Super Smash Bros. 4, players can no longer ledge cancel their aerial attacks. However, it is still possible to perform ledge cancels with air dodge and most special attacks.
Performing the technique
Ledge-canceling, while fairly simple in concept, can be difficult to perform (especially while using characters with high traction or low air speed) due to the tight spacing it requires relative to the ledge of the stage or platform. Players must put out an attack in the air while moving toward the edge of the stage, with spacing such that after landing they will continue to slide and eventually reach the edge. In essence, the character briefly touches the "corner" of the ground, with the transition from air-to-ground-to-air (or air-to-ground-to-teeter) canceling the remainder of the move. When ledge-canceling to combo, players will often try to perform the first move as close to the ground as possible while still giving it time to produce a hitbox. This results in the minimum number of frames separating the first and second hits, making more followups possible. When set up properly, players will immediately slide to the ledge, removing all lag after the first hit and allowing for an instant followup (save for the minimum of three frames it takes to land, slide to the edge, and be able to put out another attack).
Different results can be obtained when ledge cancelling from the air, based on factors such as speed, held direction, and the direction that the character is facing during the ledge-cancel. If facing the edge the character will enter helplessness if the player is holding forward or if the character has too much momentum to stop from the teeter. Otherwise, when the character is moving sufficiently slowly and forward is not held, they will simply remain in their teetering animation. When facing away from the edge, the character will enter free fall and sometimes be able grab the edge of the stage, depending on attributes such as falling speed. Remaining on stage after a ledge-cancel is more difficult than sliding off of it, and it grants the player access to any moves they can use while grounded instead of moves that can be performed while in the air.