Helpless

There are certain actions that will cause a character to become helpless (sometimes called "fallspecial"). In Super Smash Bros. Melee, air dodging caused a character to become helpless. Most characters also become helpless after using an up-special attack. While helpless, characters cannot perform any action except fast-falling, and characters are vulnerable to attack. Helpless mode is canceled by hitting the ground, grabbing a ledge, or being hit with an attack that causes the character to flinch. Additionally, several other special attacks enter characters into helpless mode after finishing the animations of the attacks while aerial.

These moves include:
 * Din's Fire
 * Dimensional Cape
 * Drill Rush
 * Egg Roll
 * Falco Phantasm
 * Fox Illusion
 * Gerudo Dragon/Flame Choke
 * Mach Tornado
 * PK Flash
 * PK Freeze
 * Quick Draw
 * Raptor Boost
 * Squall Hammer
 * Wolf Flash
 * Rollout*
 * Giant Punch**

* Only in Melee

** Only in Melee and Brawl

Landfallspecial and superdashtechnique
In debug mode, the state of the character when landing from this state is referred to as landfallspecial. Because airdodging enters this state, and wavedashing involves airdodging into the ground, when wavedashing was tried in debug mode, "landfallspecial" appeared for the character state. This led some players to believe that the "landfallspecial" designation was specifically designed for wavedashing, and that developers put wavedashing in the game intentionally, further fueling the various debates over wavedashing's legitimacy. At one point, the myth morphed to where, instead of just landfallspecial, there was purportedly another debug mode designation, cited as "superdashtechnique", "superdashattack" or other variants, created solely for the wavedashing animation. All incarnations of this story have been proven false, and should not be taken as evidence that wavedashing was intentionally put or left in SSBM.

In Brawl
Certain third jumps do not leave characters in a helpless state, and air dodges no longer cause helpless status. This completely changes the strategy of many characters.

Characters not put into a fully helpless state after using their Up Special:


 * Jigglypuff hitting an opponent with Rollout in mid-air doesn't cause it to become helpless, but Jigglypuff cannot do anything until it lands.
 * Mr. Game and Watch
 * Meta Knight glides after he uses his Shuttle Loop, his up special. If not attacked out of, the glide can eventually put him into helpless.
 * Peach can enter helpless state by pressing down during her third jump, but can cancel it by presing up again.
 * Pit's Up Special only leaves him helpless if it is not attacked out of.
 * R.O.B. cannot enter helpless state at all.
 * Snake
 * Sonic does not enter helpless after Spring Jump, his up special, although he can't use special moves after using it until he lands.
 * Yoshi reaches helpless state by canceling his Egg Roll in midair.
 * Zero Suit Samus

With the exception of Pit, Meta Knight, and Peach, all the characters above cannot enter helpless state in normal play. With the exception of R.O.B, they can enter helpless by hacking the game; they have a helpless state, but no action can cause them to enter it. R.O.B. has no helpless state, and hacking the game to force him to enter helpless will crash the game.

Trivia

 * When Kirby has the ability of any Standard Special Move that makes the player helpless in midair, the same effect will happen to him.
 * Any character - even those who cannot get their helpless state originally - can get their secret helpless state revealed by hacking, with the exception of R.O.B. Apparently, R.O.B has no designed helpless state, and the game will crash if he starts to fall helpless.
 * Hitting a character with a thrown screw attack in Melee will cause that character to fall helplessly. This is useful if you can hit with the screw attack while an opponent is away from the edge, since it denies them all their remaining jumps and recovery moves.