Ledge-canceling (also known as edge cancelling) is an advanced technique present in all Smash games in various ways. It involves players canceling the landing lag from an aerial attack or special moves by going into their teetering animation immediately after landing, or by sliding off of the stage/platform entirely. Ledge-canceling moves grants players opportunities for more movement options and for extremely fast follow-ups using attacks that do not normally have combo potential. While all aerial attacks can be ledge-canceled in Super Smash Bros. and Super Smash Bros. Melee, not all aerial special attacks can be. 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.
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, 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 follow-ups possible. If set up properly, players will immediately slide off the ledge, removing all lag after the first hit and allowing for an instant follow-up (save for the minimum of three frames it takes to land, slide off the edge, and to start another attack).
Different results can be obtained when ledge canceling from the air, based on factors such as speed, the direction at which is held, 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 to 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.
Super Smash Bros. Brawl and onward
As of Brawl, ledge-cancelling can no longer be used to cancel aerial attacks, and is now exclusively used for canceling special moves, as well as airdodges facing towards the edge in Super Smash Bros. 4. The method of ledge-canceling an airdodge is identical to that of an aerial, that is, the fighter must be moving forwards towards a ledge and land just in front of it while airdodging, also, the player must be facing the ledge they are moving towards. This matters since landing lag is applied to airdodges in Smash 4. Many fighters can ledge-cancel their special moves using the technique, most notably Quick Attack, however this also applies to the following: