Down smash (abbreviated d-smash) or down smash attack (下スマッシュ攻撃, Down/lower/under smash attack) is a smash attack performed by any character by tapping the Control Stick downward and pressing A at the same time or by pressing down on the C-stick. In Super Smash Bros. Melee, the C-stick can not be used in one-player mode.
Since Super Smash Bros. Melee, all smash attacks can be charged by holding down the A button for up to one second, multiplying damage and knockback by up to 1.4. In Ultimate, with some exceptions, these charges can be held for up to 3 seconds (or 180 frames), but the attack stops increasing in strength after the 1 second mark.
Down smashes are generally the fastest, weakest smash attack in a character's arsenal, and almost all of them hit on both sides of the character, making them useful for coverage or punishing rolls. Prior to Ultimate, they were not as flexible to use as the other smash attacks; they couldn't be used out of a dash or out of shield like up smashes can, nor could they be used in the first few frames of a dash or out of a pivot like forward smashes.
List of down smashes
Notable down smashes