A smash attack is an attack performed by "tapping" (quickly tilting) the control stick and pressing the attack button at the same time or by tapping the C-stick in Melee or Brawl. This class of attacks includes forward smash, up smash and down smash. Smash attacks generally have the highest knockback of the moves in a character's arsenal, but are also often much slower than other attacks the character has. In Melee and Brawl, they can be charged by holding the A button down, thus giving it more damage and knockback. A smash attack can be charged for exactly 60 frames, or 1 second. A fully-charged smash attack does 1.3671x damage in Melee and 1.4x damage in Brawl; for example a smash attack that normally does 16% damage will do 21.8736% damage when fully charged in Melee, while it will do 22.4% fully charged in Brawl. A character receives 20% additional knockback when hit while charging a smash attack.
In Melee's Versus mode, smashes can also be performed by pressing the C-stick in any direction. Holding the Z button or A button while pressing the C-stick results in charging the smash. Some forward smashes can be angled in the same way forward tilts can - depending on the angle and the attack, a different amount of damage may be dealt. Usually, smash attacks deal extra damage when angled up and less when angled down (usually a 1% or 2% difference), which the tradeoff being the difficulty in hitting shorter targets when angled up. Angled smash attacks can have other properties as well, such as Luigi's forward smash gaining extra IASA frames when angled up.
In Super Smash Bros. Brawl, one can play the game with 4 different controller setups. While the Wii Remote, the Wii Remote and the Nunchuk, GameCube Controller, and the Classic Controller all have control sticks to perform Smash attacks the standard way, when using the Wii Controller on its side, one can also press the direction they are attacking and press both the 1 and 2 buttons at the same time. When attacks are charged in Brawl, characters now move while flashing as opposed to just freezing then unleashing the attack. In addition, a small sound can be heard when charging a smash attack. For most characters it's a 'crack' sound, however certain smaller or "anthropomorphic-like" characters like Yoshi, Diddy Kong, Kirby, and Pikachu make a different squeaky noise instead.
Smash attacks are often powerful finishing moves or simply reaching attacks, but they usually come out slower than neutral A or tilted A attacks, and have longer lag, though their cooldown is generally good. A character who overuses smash attacks is easy to counter. The smash attack's power will also be affected with stale-move negation when it is overused.
Items such as the Fan, the Beam Sword, or the Home-Run Bat have their own forward smash, and can also be charged. Using a smash attack to throw an item often deals more damage than simply tilt-throwing it.