A tap, or tapping, is a term used in the Super Smash Bros. series that refers to quickly tilting, or tilting in a direction very hard, on the Control stick/D-pad in a certain direction. It is used to either dash, jump or drop through a platform, and can be combined with the attack button to perform smash attacks.
Different ways to use tapping
There is a number of ways to use taps, as mentioned above. Note that for the Wii remote, the equivalent to tapping is double tap, as tapping normally would act as a tilt, although jumps are still performed by pressing up just once.
A player can dash by tapping the Control stick/D-pad left or right. It's important to note that the character will run with their initial dash if tapped, and upon further uses allows faster travel speed as most initial dashes are faster than their regular run speed. This technique is called fox-trotting.
From Super Smash Bros. Brawl onward, tapping up to jump can be disabled in the Controls menu for the two games. Within tournaments, most players prefer disabling Tap Jump, as it can lead to accidental jumps when attempting to perform up tilts or up aerials, while others prefer to have it on to perform up smashes and up specials out of shield more easily, without having to press a jump button. Jumps from ledges or out of water are still possible by tapping up even if Tap Jump is turned off.
The Tap Jump option is known as "Stick Jump" in Super Smash Bros. Ultimate.
A player can fall through a soft platform by tapping the Control stick/D-pad downwards.