- Not to be confused with falling speed, which measures how fast a character falls naturally.
Differences with fast falling: the Samus on the left uses the technique, while the Samus on the right does not.
Fast falling is the act of falling quicker than usual in mid-air. It is performed by tapping down on the control stick while falling. The character will continue to fast fall until landing on the platform or taking a hit. Gravity is ignored once a fast fall is begun; the character's downward velocity is simply set to their fast falling speed without accelerating. Fast falling is a technique commonly used to speed up a character's game, especially after a short hop. It is a part of SHFFL'ing and is considered an advanced technique.
Stall-then-fall aerials have an effect similar to fastfalling, though the move is an attack, and most of the time cannot be stopped or slowed.
If players press down while hanging from a ledge, their character will begin to fast fall, whereas if pressed in the opposite direction of the ledge, the character will merely let go of the ledge. This also works with down + B attacks, except for ones that slow down falling or gain height. (An example is Fox's Reflector or Luigi's Luigi Cyclone.)
In Super Smash Bros., the character will flash and a white star will appear at his or her torso when fast-falling. In Super Smash Bros. Melee, a "whoosh" sound will be heard when fast falling, but there is no visual indicator, making it harder to tell when many other noisy things are going on. There is no indicator in Super Smash Bros. Brawl.
 Fast falling speeds in SSB
- Oddly enough, Metal Mario's fast falling speed (70) is lower than his regular falling speed (100). This means that he would actually slow down by fastfalling, though he would probably then quickly re-accelerate to his regular falling speed.
- Giant Donkey Kong's fall speed and fast falling speeds are 72 and 100, respectively.
 Fast falling speeds in Melee
- Giga Bowser and Wireframes have fast falling speeds that equal their regular falling speeds. Because of this, fast falling with them does not have any effect except for slightly increasing how fast they reach their regular falling speed.
 Fast falling speeds in Brawl