Buffering is a game mechanic in which a player may input an action shortly before it can be executed in-game, resulting in the action being carried out on the first possible frame. Many different video games of various genres implement a buffering system of some sort, but its implementation is arguably most notable in fighting games, where a decreased emphasis on frame-perfect inputs means easier access to combos, thus improving accessibility for casual players. The mechanic has existed in some form in every Super Smash Bros. game, although Super Smash Bros. Brawl was the first game in the series to allow any input to be buffered, as opposed to a select few actions.
There are negative effects to buffered inputs; most notably, a player may input a move that does not activate until their fighter is in a different spot, such as a jab near the ledge becoming a neutral aerial if they leave the stage before it can activate. This kind of situation can be deadly for characters with laggy aerials, such as Ike, whose recoveries do not provide enough vertical distance to recover after the attack ends. Unintentional buffered actions are significantly more common in online play than offline play, due to built-in frame delay used to stabilize matches combined with Wi-Fi lag that can result from a poor connection.
In the original Super Smash Bros., there is no universal buffer system, so apart from a select few actions, inputs generally need to be frame-perfect for optimal play. This is a commonly-cited reason that some professional players state that Smash 64 requires more technical skill than later games in the series.
Bufferable actions include:
- Stick related actions (such as dashing, jumping and fast falling) with a 2-3 frame window (only works if the stick is held).
- Attacking after a turnaround.
- Inputting a consecutive neutral attack hit (also applies to Ness's down tilt).
- Attacking after being in hitlag when hit with armor (if the armor does not break).
- Any action when starting a game or un-pausing (with the exception of pause).
Much like its predecessor, Super Smash Bros. Melee does not buffer inputs in general, save for a select few. The previous game's bufferable actions were largely carried over to Melee, although there are some changes:
- Attacking after a turnaround can no longer be buffered as attacking during a turnaround will now cancel the turnaround animation.
- It is no longer possible to buffer actions out of hitlag when hit with armor.
- It is now possible to buffer actions Out of Shield after shieldstun by holding the C-stick together with a shield input. When using a regular stick, the player cannot buffer out of shield options but they can if they hold the C-stick.
Super Smash Bros. Brawl was the first game in the series to introduce a universal input buffer for basic actions, although not all actions are included, as detailed below. When the player is performing an animation, there is a window of 10 frames at the end of most moves and animations where the player can buffer any action, including attacks, jumps, and dodges. This allows the player to easily perform frame-perfect actions without having to perfectly time their button presses; in other words, they have 1/6th of a second to enter a precise input rather than 1/60th of a second. If the animation is shorter than 10 frames, the player can still buffer actions, but they will have less time to do so.
Exceptions to this mechanic include:
- Any action out of a jump, when inputted on the jump's first frame.
- Aerials or air dodges out of non-tumble hitstun (these actions can be buffered for the end of a hitstun animation, but not the end of hitstun itself, outside of a buffered double jump immediately beforehand).
- Any action out of tumble hitstun.
- Any ledge option using the control stick.
- Grab aerials in the air if used on their own (can be buffered if the player buffers a double jump beforehand).
- Airborne item catches and Z-dropping after an air dodge.
- Shield after dropping the input during the 10 frame period.
- Any action except for a down tilt, after a down tilt with no interruptible frames.
Additionally, forward tilt, down tilt, and non-smash-input side and down special cannot be buffered unless the control stick is released before the buffer window ends.
If the player attempts to buffer multiple distinct actions within a buffer window, usually the game will only carry out the first of these actions; exceptions to this rule can result in advanced techniques, such as:
- Performing any action on the first frame of a ground jump.
- Performing an aerial/air dodge/special move on the same frame as a double jump. The player has to buffer the double jump before the desired aerial action; if inputted on the same frame, the double jump will override the action.
- Instantly turning around and performing an action (such as attacking). Normally, the player has to turn for one frame before being able to perform turnaround actions.
- Performing an instant dash attack or dash grab by buffering a dash, letting go of the control stick and then pressing attack/grab.
- The player can also input an up smash after buffering a dash attack to perform a Buffered Dash attack canceled up smash. The player performs an up smash while carrying over the momentum from the dash attack.
In Super Smash Bros. 4, the universal buffer system returns, albeit with some adjustments. A built-in hierarchy now dictates in what order actions are used, when multiple actions are inputted within a buffer window. Special moves have the highest priority, followed by shielding, attacks, jumps, and stick inputs, in that order. For ledge options, ledge jumping has the highest priority, followed by ledge attacking and ledge rolling. Due to this hierarchy, buffering both a control stick input and a button input (or multiple) at the same time is impossible, making it more difficult to buffer moves like dash attack or dash grab out of shield. This also means that multiple actions which could be buffered in Brawl (like an immediate double jump aerial or a dash attack) can no longer be buffered. On the other hand, most of the actions which cannot be buffered in Brawl still cannot be buffered in Smash 4, with the notable exceptions of buffering actions out of hitstun and buffering powershield canceled attacks.
Brawl's inability to buffer forward tilts, down tilts, and non-smash-input side and down specials has been removed, with the exception of down tilts and down specials when performing a soft or hard landing (although this can still be bypassed by releasing the control stick before the buffer window ends). The issue where moves could not be buffered out of a down tilt with no interruptible frames has also been fixed.
Ultimate largely retains the buffering system from Smash 4, although the buffer window is now 9 frames, down from 10. It also introduces a second universal buffering system, in that holding an input through the end of an animation will now cause the held input to be buffered; this method of buffering only existed for specific actions, such as walking and shielding, in previous games. The input can be made as early as desired, but must be held until the beginning of the standard 9 frame buffer window. For instance, if the forward smash input is held while the fighter is in freefall, the move will begin charging as soon as the fighter lands on the ground. It is notably no longer possible to buffer a full hop aerial, for inputting an aerial during jumpsquat will always result in a short hop aerial, even if the jump button is being held.