A spotdodge (その場回避, on-the-spot dodge), also called a spot dodge or a sidestep, officially known as a sidestep dodge in Super Smash Bros. Melee and Super Smash Bros. Brawl, and as an on-the-spot dodge in Super Smash Bros. Ultimate, named EscapeN by Melee's debug menu, and Brawl and Super Smash Bros. 4's internal character files, is a maneuver that renders the character intangible for a few frames, with the duration varying based on the game and character. Functionally similar to an air dodge, it is performed by pressing down while shielding, and can be employed to evade any and all harm of short duration. It is perhaps most useful in dodging projectiles and items along with quickly counter-attacking foes during the ending lag of their missed attack.
Though the spotdodge animation shows the character leaning into the back or foreground, the intangibile state gained allows the character to dodge all attacks, including those that come from the foreground or background, such as the lava wave in Norfair. The character's leaning position after the intangibility ends can also result in evading attacks due to the three-dimensional nature of hitboxes, most notably King Dedede in Brawl being significantly outside the playing plane for most of his spotdodge's ending lag.
Spotdodge frame list in Melee
Spotdodge frame list in Brawl
* Moves back slightly.
** Moves significantly back on the Z-axis, to where he's intangible to most attacks for all but 1 frame in his spotdodge. Attacks need to have wide hitboxes that reach far into the Z-axis, or hit low enough to hit Dedede's foot that sticks out, to hit him during his vulnerable frames in his spotdodge.
Spotdodge frame list in Smash 4
Prior to version 1.1.0 of Smash 4, all spotdoges had one more frame of intangibility. This list shows the frame data of spotdodges as of the current version of the game.
*Bat Within activates on frames 1-4
Spotdodge frame list in Ultimate
In Ultimate, spotdodges have had their startup standardized across the cast, so every character gains intangibility starting on frame 3 (with the exception of Bayonetta, who can instead activate Bat Within starting on frame 2). Additionally, all characters' spotdodges can now be canceled 5 frames earlier than usual into any ground attack (including special moves, but excluding grabs and dash attacks, the latter since they require the user to dash first), making them more effective for retaliating against opponents after dodging their attacks. However, a staleness mechanic has been introduced for spotdodges, which reduces their intangibility frames and lengthens their duration if they are performed repeatedly, gradually leaving the user more vulnerable. This mechanic is shared with rolls and air dodges.
The formula to determine a spotdodge's duration before it can be interrupted is D * (1 + P), plus one frame if stale, where D is the total duration of the spotdodge when fresh, and P is a penalty value that increases by 0.06 for every spotdodge, capping at 0.3. As a result, five consecutive uses of spotdodges will fully stale them. The penalty is reset per each spotdodge used every time the player spends roughly one second without using any kind of dodge. When fully stale, all spotdodges grant intangibility three frames later, making them worse for dodging attacks quickly.
In the list below, values in parenthesis show the total frames of spotdodges when canceled into an attack. Attacks used out of spotdodges cannot be canceled into aerials.
*Bat Within activates on frames 2-5