Edgehogging
Edge-hogging is the act of holding onto a ledge so that a recovering opponent cannot grab it. Casually oriented players tend to dislike the tactic and will often claim it to be "cheap", while competitive oriented players see the technique as fully legitimate, being fully combatable, and agree that it is a critical part of recovery disruption.
In SSB
In Super Smash Bros., certain characters, such as Fox, can use the turn-around animation out of a dash to move off the ledge and turn-around quickly to prepare an edge-hog.
In Melee
The most common method of edge-hogging in Melee's competitive play is to wavedash back while near the edge, which should result with the characters sliding off of the stage, falling a short distance, and then quickly grabbing the edge. The character then usually uses the invincibility from the edge to avoid being hit by the opponent's recovery move. Other methods include moonwalking, doing a reverse neutral special then sliding off, using certain attacks which allow one to grab the edge faster or while attacking (i.e. Bowser's Whirling Fortress), or simply short hopping back and grabbing the edge. Another method, called the pivot edge-hog, involves pivoting very close to the ledge. The character will skid short distance during the turn-around animation and land on the ledge.
During the edge-hog, smashers typically roll from the ledge as it grants them invulnerability to the recovering opponent's attacks (usually up special) while still retaining possession of the ledge, in addition to usually lasting the longest of all actions and so hogging the edge for longer.
Edge-hogging in Melee earns the "Edgehogger" bonus. The bonus is earned whenever one character is holding an edge and someone else moves into a spot where they can otherwise grab it, regardless of whether the edgehogged character is KO'd.
In Brawl
While it is easier to grab ledges in Brawl, successful edge-hogging requires better timing because the player can no longer edge-hog their opponent by rolling to the stage from the ledge. As a result, some players use hugging to edge-hog their opponents when they aim their recovery move to the ledge. However, edge hogging should be done with precise timing and caution, because if one miss-times the edge hog, the invincibility will wear off and the edge hogger can be attacked, mostly by a deadly stage spike.
In SSB4
Edge hogging does not return in Super Smash Bros. 4. Any character can steal the edge from the ledge-grabbing character [1].