Weight

Weight is a measure that determines how much resistance to knockback a character has. It mostly affects horizontal knockback, since falling speed is more important when calculating vertical knockback. Different weights are only truly present in Super Smash Flash 2 and are non-existent in Super Smash Flash, where all characters have the same "weight".

Overview
Weight is a concept that can be described as how difficult it is to send a character flying. Different weights present both advantages and disadvantages to each character. Heavier characters are harder to KO, but most are susceptible to horizontal combos and chain grabs; on the other hand, most lighter characters have the advantage of being less susceptible to combos at higher percents while being easier to KO. The weight multiplier for knockback is represented by the value 200/(100+W), where W is the weight of the character.

Differences from the Super Smash Bros. games
Weight in Super Smash Flash 2 does not share all of the effects that are present in the  games. The length of throwing animations is not dependent on the weight of the opponent being thrown and chain grabs do not necessarily work the same way as they do in the main games. For instance, in Super Smash Flash 2, is vulnerable to certain chain grabs, like 's up throw. However, in Melee, he was not affected by it due to his weight.

Types of weight classes

 * Light: Easiest to KO and get sent off stage at lower percents. Most characters in this category have a small frame. Examples are:, and.
 * Medium-light: Middleground between light and medium characters. Examples include:, and.
 * Medium: They are neither easy nor hard to KO as their weight does not present neither clear advantages nor disadvantages. Characters who fit into this category are, and.
 * Medium-heavy: Middleground between medium and heavy characters. They can be easily comboed until medium percents, they are harder to KO then medium weights, but can die earlier then heavies. Notable examples include:, and.
 * Heavy: Hardest to KO and send off-stage. Most have a large frame. Examples of these characters are and.

Trivia

 * Zero Suit Samus was made a medium-heavy character in the early patches of demo v0.9b, but this was corrected later and she is now a medium-light character.
 * However, Zero Suit Samus is still heavier than she is in the Super Smash Bros. games. Her weight in Super Smash Flash 2 is 85, while in Super Smash Bros. Brawl it is 81, and in the later Smash installments, 80.