Frame speed multiplier

A frame speed multiplier (also known as a frame speed modifier) is a multiplier applied to the total length of an attack or period of an attack, allowing the duration of a move's animation and properties to be modifiable without needing a completely new animation, or even allowing the attack to change rate continuously.

Depending on the game, the meaning of the technical number used for a multiplier is reversed:
 * In Super Smash Bros. Brawl, a frame speed multiplier of 0.5 means the attack progresses at half speed (straight multiplication)
 * From Super Smash Bros. 4 onward, a frame speed multiplier of 0.5 means each frame now takes 0.5 frames, and so the attack moves at double speed (reciprocal multiplication).
 * Despite this, there are still certain moves from Smash 4 onwards which use a straight multiplication frame speed modifier to alter their animation speed (such as with Homing Attack while Sonic is rising).
 * Earlier games in the series do not have the ability to modify only part of an action's speed in code, though they may apply internal multipliers to an animation's overall speed. In these games, frame speed multipliers work the same as in Brawl, using straight multiplication.

Usage of frame speed multipliers

 * Several normal animations have their execution speed modified to match their coded result:
 * Speed of walking and running
 * Length of landing lag (particularly prior to Ultimate).
 * Weight dependent throws have their speed change calculated as a frame speed multiplier (weight/100) (Melee/Brawl), (26 x (weight / 100 - 1)) (Smash 4).
 * Hitstun animations contain a frame speed modifier that's used the match the overall knockback speed sustained (Smash 4/Ultimate).
 * Moves with execution speed based on some input or changing property (such as Mach Tornado and Rollout) use a frame speed multiplier to match their appearance to their movement.
 * Custom moves that are faster or slower than the regular variant almost always use frame speed multipliers, so they can reuse the same animations.
 * Starting from Smash 4, moves that are changed in updates to gameplay tend to use frame speed multipliers to alter their timing, as it is much more efficient than the memory space and time needed to replace the entire animation. This is also used with animations carried over from previous games for the same purpose/reasons.
 * Many newcomers from Smash 4 onwards use frame speed modifiers to alter the speed of their attacks, even without the influence of updates.
 * Ore Clubs uses a frame speed multiplier on all swings.
 * Fans use a frame speed multiplier on all swings in Smash 64 and Melee.
 * Bosses use a similar system to alter the speed of their attacks based on the set difficulty.