Lag

Lag is a term in the  series that indicates a period of time when a character is performing an attack animation, but the move is not active. During this time, the player is unable to perform in any other action, with the exception of moving through the air when concerning aerial moves. The two main categories of lag that every move in the game has are startup lag and ending lag. For aerials and certain special moves when used in the air, there's an additional form of ending lag that can occur called landing lag. The more lag a move has, the easier it is to evade the attack and punish the user. Typically, powerful moves have more startup and/or endlag, though this is not always the case.

In Super Smash Flash
In Super Smash Flash, characters have little start up and ending lag in their attacks which allows them to keep throwing out attacks continuously without being punished.

Due to the game's mechanics, landing lag did not exist in any form: characters who touch the ground after simply jumping would instantly go to their idling animation, and would, upon touching the ground while performing an aerial attack, keep playing said attack's animation.

In Super Smash Flash 2
Super Smash Flash 2, similarly to the official Smash games, contains lag. Comparing to the official games, however, SSF2's attacks still suffer less lag overall, with the amount of existing incredibly laggy attacks being considerably smaller.

Prior to the Beta version, helplessness did not affect landing lag at all. However, from that version onwards, characters who land while being helpless will enter a "heavyland" animation, which usually lasts for three times as much as the normal landing animation.

The majority of character attacks have little to no landing lag, and, unlike Super Smash Bros. Melee, will get their landing lag instantly auto-cancelled, if the character lands at specific portions of the attack. The auto-cancel windows are also longer when comparing to the official games.

Lastly, it is usually advised for players to perform certain aerial attacks when they fall into the tumbling animation, in order for them to not be put into a tech chasing situation or an edgeguarding one. Players can also time their aerial attacks carefully while tumbling, so they end up auto-canceling when landing.

Startup lag
Startup lag, also known as just startup and windup, is the time period between a move being initiated and the move having an effect, such as the length of time before a hitbox is first produced. Examples of moves with notable start-up include 's Hammer and 's forward smash. There are some moves that have little start up such as 's and 's Rest.

There is some start up for moves that can be used for recovery such as 's Fire Fox and 's Vanish which will leave them open to being edge guarded.

Ending lag
Ending lag, also known as cool down, is the time period between the end of the active duration of an attack and the first act-able frame following the end of the move's animation. For instance, the length of time after an attack's hitboxes ceases that the character can move again. Almost all attacks have more ending lag than startup lag, though generally, attacks with lower start-up lag tend to have proportionally more ending lag and vice-versa. Attacks such as 's dash attack and Jigglypuff's down smash are notorious for having an extreme amount of ending lag. However, there are a few attacks with little ending lag, such as Fox's or Pikachu's down tilt.

There are some ways to avoid the ending lag of certain attacks. Fox is able to cancel the ending lag of his reflector by jumping out of it while he can cancel the lag of his blaster by auto-canceling it. Another way to cancel the ending lag of a move is by ledge canceling, which can do by performing a sliding up tilt off a ledge.

Landing lag
Landing lag is the lag incurred when an airborne character lands on the ground for any reason. The amount of lag depends on what action the character is performing upon landing.

Normal landing
Characters will experience normal landing if they land on the ground without performing any action, such as an attack, outside of air dodging. This will give characters about 3–6 frames of lag before they are able to move again. The amount of lag a character experiences varies depending on the character.

Aerial landing
If a character lands while in the middle of an aerial attack, they go through a unique animation that lasts for significantly longer than a normal landing. A clear example is 's down aerial; hitting the ground during the attack results in Link's sword getting stuck, and he has to spend a notable amount of time pulling it out before he can do anything else. Each aerial attack has its own amount of landing lag; most special moves tend to continue execution instead of being interrupted when the user lands while using them, though a few undergo their own unique landing animation if the character lands after initiating them in the air, such as Falcon Kick. Most aerial attacks have a few frames at the beginning and the end of the animation, during which they will automatically cancel the move into their idle stance, nullifying all landing lag in the process.

Wi-Fi lag
Wi-Fi lag is the drop in FPS (frames per second) of a game due to a slow or inconsistent connection while playing online. In SSF2, the online mode uses peer-to-peer connections in order to get the best performance. However, if a player has a weak Internet connection, the distance between the players is too far, or a player's computer is not strong enough to run SSF2 smoothly, the game can lag quite a bit. Typically, in order to get the best performance possible, players should stay away from stages with many moving elements, and play against only those players that have strong computers and connection speeds.

Below is a list of types of Wi-FI lag:
 * Slowdown: Slowdown is a form of lag in which the game plays slower, but at a consistent rate. This form of lag is the least interfering, as it does not typically result in dropped inputs or inconsistent timing delays that plague the other forms of lag. Still, it can cause headaches for players who are normally used to playing offline, due to having to adjust the timings for their inputs.
 * Lag spike: Lag spikes occur when an otherwise lagless match has a few rough patches in which the game suddenly slows to a crawl. Usually, a lag spike lasts for only a brief moment, resulting in minimal interference. However, it typically causes inputs to be dropped during the spike, and can prove to be problematic in situations where a single mistake could result in a loss of a stock, such as during the offstage game.
 * Stuttering: Stuttering is a form of lag where the game runs at normal speed, but is constantly pausing at an erratic rate for random intervals of time. This lag is relentless in its attempts to screw over the players in the match, making some otherwise very simple tasks nearly impossible to execute properly. In the worst cases, stuttering can make the game virtually unplayable.