KO

A KO, short for knock-out, is the term for when a character loses a stock or a point in the  series and Fraymakers. A knock-out occurs when a character touches a stage's blast line, usually as a result of being attacked by another character or running off by themselves.

After a KO, the character revives back on the stage. In stock mode, if the character is KO'd after their last stock, they will no longer revive, and if there is only one other character left, the game ends.

In Super Smash Flash 2, there are three unique KO effects: normal KOs (also referred to as blast KOs), star KOs, and screen KOs. There is a fair bit of controversy surrounding the idea that, since the choice of star KO and screen KO is random, two players may end up being KO'd at different times, even though they hit the upper blast line at the same time. If both players are on their last stock, this could determine the outcome of the match.

Self-destruct
A self-destruct, often abbreviated SD or referred to as suicide, is the term for when a character gets KO'd without being hit by opponents. A self-destruct may occur to a player in Super Smash Flash if they touch the stage's blast line without being hit in the air or into the blast line, while in Super Smash Flash 2 and Fraymakers, it only occurs if the KO'd player was not hit by an opponent during the stock. It may also occur if the player gets KO'd by a stage hazard.

Each self-destruct subtracts one point from the player's score. While Super Smash Flash counts each self-destruct as a fall (only the falls are included in the score), Super Smash Flash 2 counts self-destructs and falls separately.

Super Smash Flash includes two bonuses related to self-destructs: "SDs", which penalizes 500 points for every self-destruct the player commits, and "Self-Destructor", which penalizes 2000 point when player repeatedly SDs in a match.

Sacrificial KO
In a sacrificial KO, a character both KOs their opponent and self-destructs with a single move. In most cases, this involves grabbing the opponent and dragging them downwards to the bottom blast line. These are impossible to perform in Super Smash Flash, due to characters being unable to grab or throw.

Star KO
A star KO is a type of KO in Super Smash Flash 2 in which a character is knocked out by passing the upper blast line, tumbling and falling in the background while screaming, emanating music notes, or yelling, eventually disappearing as a star. Characters who have above-average accelerated falling speed are less susceptible to this than characters with below-average falling speeds.

Screen KO
A screen KO is a type of KO in Super Smash Flash 2 in which a character falls and crashes into the screen, while making a sound, when they are sent flying above the top blast line. Characters hit the screen with their fronts and the screen cracks as a result, adding to the effect that the character is breaking the camera. Additionally, only one character can be screen KO'd at a time, as all other vertical KOs will be star KOs until the screen KO is finished.

One-hit KO
Some attacks, most notably a Home-Run Bat swing, can KO an opponent at 0% from center stage. Attacks of this strength are said to be able to one-hit KO — OHKO for short — an opponent.

In Super Smash Flash, there are no OHKO attacks, as hitboxes have a constant, per-frame damage output rather than a single set value. However, instant-KO attacks are commonly erroneously referred to as OHKOs regardless.

Trivia

 * In Super Smash Flash, unlike in Super Smash Flash 2 and the official Super Smash Bros. games, the blast that appears whenever a character gets KO'd is always gray in color, regardless of the team they fight on or whether or not they are a computer player.
 * ,, and each let out musical notes as their star KO yells. Bandana Dee uses the losing jingle from the  games, Mr. Game & Watch emanates four beeps, and Sandbag produces a slowed-down version of the Party Ball sound from Super Smash Bros. Melee.
 * Certain characters can be seen dropping weapons during their star KO or screen KO animations. For instance, Sandbag drops a Home-Run Bat upon being star KO'd, and drops his Material Blade upon being screen KO'd.