List of bugs and glitches in Super Smash Flash

A software bug, or simply a bug, is an error, flaw, failure or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. On the other hand, a glitch is a short-lived fault in a system, such as a transient fault that corrects itself, making it difficult to troubleshoot. Though similar, bug and glitch differ in that the former often cast as the weightier and more blameworthy pejorative, while the latter suggests something more mysterious and unknowable inflicted by surprise inputs or stuff outside the realm of code.

Bugs and glitches in Super Smash Flash
Since Super Smash Flash was coded by an inexperienced Cleod9 as his first major project in a period of four months, it is not a very stable Flash game. Below is a list of some notable bugs and glitches in the original Super Smash Flash. Note that the majority of these bugs do not have official names and have been given conjectural ones.

Damage input flaw
This is a bug caused by the game's methods for determining damage calculations. Once an attackbox makes contact with an opponent, the attack's damage will be applied to the opponent on every frame that said attackbox overlaps the opponent's hurtbox. This results in attacks dealing ludicrous amounts of damage across the board, and moves with moderately large attackboxes and active frame count (such as ' down attack) being able to deal over 100% by themselves.

and are not exempt from this bug, and their enormous attackboxes cause their moves to deal more hits and be stronger on average comparing to the playable cast. This bug, combined with the Instant-KO bug (see next section), causes unlocking to be incredibly difficult without usage of the skip exploit or the easy avoidable Hands bug (both of them listed below), as failing to dodge even a single attack can lead to the loss of a stock.

Instant-KO attack
Alongside the damage input flaw, this is one of the most infamous bugs in Super Smash Flash, being so prevalent and unavoidable that it has become synonymous with SSF's physics. Every attackbox that deals vertical knockback, on contact with an opponent, will multiply their momentum (horizontal and vertical speed prior to the hit) according to their damage, and stack the move's knockback on top of it, causing opponents at medium to high percentages to get KO'd almost instantly.

This bug does not affect attacks with horizontal knockback, however, and only attacks with vertical knockback are capable of instantly-KOing opponents. Every character's up and down attacks deal vertical knockback.

Instant-KO attacks cause matches in SSF to frequently be over within seconds. As a result of its prevalence, it almost single-handedly defines the metagame; the most important trait for determining character viability is based on how easy it is to get an instant-KO attack off on their opponent. Despite the name, this bug is not comparable to the one-hit KO (whom it should not be confused with) for the reasons specified above.

Skip bug
This is one of the more popular bugs in Super Smash Flash due to the beneficial results it can be exploited for, as well as for other curiosities. It causes the game to immediately skip to the next or previous scripted event, with events including menus or stages in certain game modes. It can be executed by opening the right-click menu or Control menu and selecting either "Forward" (or "Step Forward") for the next event or "Back" (or "Step Back") for the previous event, or by pressing their equivalent key shortcuts.

The most notable use of this bug is as an exploit in Classic, Adventure and All-Star, in which skipping to the next event will cause the player to advance to the next level without actually needing to play the previous one. Contrarily, skipping to the previous event forces the player to replay the previous level. This exploit is unable to function properly in Target Test, however, as not only does it not skip the player to another level, but it restarts the level with another fighter's target layout in a fixed order, forcing unusual and occasionally impossible situations. This is especially notable with, who is sent into 's layout, which has a target that is inaccessible without his boulders. When skipping backward with or forward with, the first and last character IDs in the roster, respectively, the game will go back to the Target Test character selection screen, aborting Classic.

This also leads to other glitches and bugs, noted below.

Night glitch
This glitch can only be found in Target Test, due to the lack of a background on Kirby Hub Room. To exploit this glitch, the player has to finish a character's target test; immediately after the announcer says "Complete!" or "New Record!", the player must use the skip bug. This will restart the level with a purple background, dubbed fittingly the "night glitch." This glitch is often accidentally triggered when players, impatient with the results screen, use the bug to advance forward and find themselves stuck in Target Test yet again with a differently colored background.

Cloud and Crono's fast unlock
The skip bug can also be exploited to challenge and unlock and  without using the intended methods of completing 100-Man Melee and 3-Minute Melee.

The player has to start a round of Cruel Melee with any character. Once the match has begun, the player must use the skip bug to advance forward and Multi-Man Melee will then be completely skipped, which will access the character selection screen for Burly-Brawl Melee (even if it has not been unlocked yet). The player must start and skip a Burly Brawl Melee match in the same way, leaving them with the "Challenger Approaching!" screen for Cloud, where victory will unlock him. This bug can be repeated over and over, even with Cloud himself, and the notice that reads he has been unlocked will also be shown again upon defeating him. Said notice will also be recorded again on the Special section in Data.

Using the skip exploit once more during Cloud's unlock match or during the notice that reads Cloud has been unlocked will take the player to the "Challenger Approaching!" screen for Crono. As with Cloud's method, it can be repeated over and over with any character, even Crono, and the notice will also be recorded again on the Special section in Data.

Early stages
Using the skip bug in VS. Mode or Training can allow the player to play on the unlockable stages and  without having to unlock them first. This is done by first entering a match on a certain stage and then skipping to a match on a different stage until reaching said stages. For Battlefield, the player must skip forward from Peach's Castle or backward from, and for Final Destination, the player must skip forward from Emerald Hill Zone or backward from.

Blank menu
Attempting the skip bug during Crono's match or the notice screen will take the player to an empty menu screen with an unusable Back button. To solve this, the player must either close the window or, preferably, use the skip bug again, which will take the player to the character selection screen for Training and everything will go back to normal, albeit with the Final Destination and Menu music overlapping each other.

Null character
If the skip bug is used on a character selection screen to advance forward without choosing a character first, an empty character will be chosen with no sprites and no collisions. This character will fall indefinitely, self-destructing from the bottom blast line when available.

If this is done on Target Test, the null character will fall infinitely, showing a permanently white screen, since Kirby Hub Room has no blast line programmed.

Note that this will only happen in situations where the game expects there to always be a character, such as when the null character is player 1. Attempting in Training or VS. Mode with any player other than 1 while player 1 does have a character chosen will simply create a one-person match. In the case of the latter, a stock match will end instantly, assuming the only player to be the last one standing and, therefore, the winner.

Empty All-Star
If the skip bug is used in All-Star, the current opponent will be taken out of the rotation as if they were defeated, but the game will not advance the player's progress in the mode. This leaves a gap in the lineup, which is filled by an extra at the end. The more times a player uses this bug, the more times they will have to fight Mr. Game & Watch. If all characters are eliminated in this way, a single Mr. Game & Watch will be fought repeatedly, even as the mode advances to where two or three opponents are supposed to appear; the remaining opponent slots are occupied with null characters.

Master Hand pause exploit
There is a bug while fighting Master Hand and/or Crazy Hand that facilitates facing these bosses; when they attack the player and then they pause the match, both Hands' animation attack will continue but the player will not take any damage. This can be exploited by repeatedly pausing the instant the Hands strike.

Early Final Destination
For unknown reasons, the unlockable stage Final Destination becomes available for VS. Mode and Training whenever the player unlocks a character. It disappears once the player closes the game, though, but can be repeated by unlocking another character. This glitch can be the result of Final Destination's unlock method, which requires the player to unlock all the secret characters.

Item physics bug
If a player throws an item and pauses the game, the item will make an abrupt stop in place only to resume its way once the game is unpaused. If the item is thrown is midair, it will slowly descend in a straight line until it touches the floor or disappears on-screen. A thrown Bob-omb will immediately explode upon contact with the floor after pausing and will fail to deal any damage and knockback should there was a player in its proximity, unless the game is unpaused right during the quick explosion animation.

Screwy items
This glitch is only possible in Training mode, as it requires the player generate a countless amount of items of the same kind while holding or attempting to grab one of the items until they flash, this is noticeable when a glitchy rectangle is visible around the frame of the generated pile of items. Regardless of the item, upon trying to use the item normally, the player will be unable to attack at all afterwards, except for the down attack, as the game still thinks that the character is holding the item; in order to being able to attack again the character must be KO'ed. The effects after attempting to use an item after picking it are the following:


 * Bob-omb: The character gets hit by multiple explosions that deal up to 600% of damage and will usually get instantly KO'd unless the player can react fast enough to stop the launch. Pressing attack again will do nothing.
 * Fan: Every time the player presses attack, the character hits himself/herself and takes damage.
 * Flipper: The character can throw the Flipper over and over again by pressing attack continuously. The Flipper follows the player's eyesight and he/she can move the Flipper by moving the character. If the player throws the Flipper upwards, the character hits himself/herself and takes damage.
 * Fire Flower: Every time the player presses attack, the character burns himself and takes damage.
 * Heart Container: The character can hold and use it, but it will have no effect. If a CPU player runs into it, it will use the item and recover damage. After that, the character cannot attack except for the down attack. There are times no oddities will happen and the player will simply pick the Heart Container and recover damage as usual.
 * Home-run Bat: Every time the player presses attack, the character hits himself/herself and takes damage. The bat will always automatically charge a Smash attack and will make its characteristic "Ping" sound effect upon contact with the character but it will not KO them as it is expected to do.
 * Maximum Tomato: The character can hold and use it, but it will have no effect. If a CPU player runs into it, it will use the item and recover damage. There are times no oddities will happen and the player will simply eat the Maximum Tomato and recover damage as usual.
 * Motion-Sensor Bomb: It follows the player eyesight and the player can move the bomb by moving the character. It will fly in an exact straight horizontal line. Pressing attack again will do nothing.
 * Saber: Every time the player presses attack, the character hits himself/herself and takes damage.
 * Shell: The character can throw shells over and over again by pressing attack continuously. If the character is using a shell, it follows the player eyesight and the player can move the shell by moving the character. Also, every time the character uses a shell, the character hits himself/herself and takes damage.

Mega explosive damage bug
This bug works in Training mode with either an explosive item, Bob-omb or Motion-Sensor Bomb. For Bob-ombs, the first player must place a large number of Bob-ombs around the second player, then throw a bomb so that it explodes and sets off the other bombs without touching the second player with the initial blast. In the case of Motion-Sensor Bombs, set a bunch of them in one place, then walk into them. If the player or the opponent survived, the player will not be able to use any moves at all. In both cases the bombs will explode in a chain dealing over 1000% damage but with minimal knockback.

Suspended automatic items
Only possible in Training mode, the player has to generate as many Bob-ombs as possible then attack them with a battering-type item, like the Saber or the Home-Run Bat. If done correctly, the Bob-ombs will explode and the item the player attacked with will be suspended in midair, rendered unusable. Pausing and unpausing will cause the item to "come back to life" and automatically charge a side attack, hitting the opponent if they get too close. This process can be repeated several times by pausing and unpausing until the item disappears.

Collision detection bugs
In Adventure mode's first level, Super Mario World, there are some odd collision detection behaviors on the plateaus and warp pipe found on the stage. If attacked and launched far enough by an enemy, the character will pass through the solid parts, ignoring the collision detection, and get inside the plateaus and warp pipes. The character can get out by merely walking out the direction they were launched in, but there are chances he/she might get stuck in the area, forcing the player to quit.

Similarly, it is possible to clip through the pipe on Peach's Castle, or the floor of Final Destination if the hands hit the player with their Stone Fist technique.