It is charged by holding the "special" button and executed by releasing it. Charging raises the speed, damage and knockback of the attack. Jigglypuff can change direction back and forth during the Rollout, but only when grounded. The grounded version deals high horizontal knockback that KOs at relatively low percentages, whereas the aerial version sends the opponent straight upward, but puts Jigglypuff in a helpless state if the attack ends while Jigglypuff is still in the air. Hitting an opponent causes Jigglypuff to rebound for a short distance. It is capable of dealing 18% damage when fully charged (when the higher-pitch sound has started). When Kirby copies the move, he attacks in a manner similar to Wheel Kirby from various Kirby games.
If used in the air or off of a ledge, Jigglypuff takes a long time to end the move, so it's best used on the ground. If Jigglypuff collides with a wall, it will continuously rebound off the wall, until the move ends.
The move can now "curve" in midair to prevent going off the side of the stage. This can even go to a degree where Jigglypuff is falling straight down, spinning, and when it lands, it will move in the opposite direction.
If Jigglypuff now collides with a wall, but the control stick is still tilted towards the wall, Jigglypuff will strike the wall again, then rapidly spin against it, emitting blue shock waves and a drilling noise, and causing pure vertical knockback to anyone who is hit.
While using Rollout in the air no longer leaves Jigglypuff helpless if it hits an opponent, it will continue spinning from the rebound, making it effectively "helpless" while floating down, and it cannot grab a ledge until it lands. If there is a gap below, this could result in a self-destruct.
In SSB4, Rollout has been severely nerfed despite being reversible, easier to control and being more powerful on slopes. It deals 14% damage, has much less knockback, and KOs at much higher percentages, around 135%. However, if Jigglypuff does an uncharged Rollout, falls on the ground, and an oppponent is there, they will take damage.
Jigglypuff can perform a Rollout glide where it flies through the air further than normal if it attempts to reverse the direction of Rollout the frame after rolling off a ledge. If Jigglypuff tries to reverse its direction while rolling down a slope, it will instead gain a very slight vertical boost and begin Rollout gliding through the air.
Jigglypuff can not move to the left or right after landing Rollout anymore, but oddly, any conditions, items or effects that cause Jigglypuff's fall speed to increase also restores the ability to move to the left and right after landing the move, and the higher its fall speed becomes, the faster it can move, increasing at a rate greater to the rate of fall speed increase. This includes being metal, mega, wearing the Bunny Hood or being in a Heavy Smash. Since Kirby's fall speed is higher than Jigglypuff's, he can do so by default when copying the move.
Special Move customization was added in Super Smash Bros. 4. These are the variations:
Rollout is a physical Rock-type attack introduced in Generation II in the Pokémon games. Learned mostly by spherical Pokémon, it can hit 2 to 5 turns in a row. Its starting base power is at a low 30 but its power will double after every hit. If Defense Curl is used beforehand, Rollout's starting base power will be doubled to 60, resulting in the most powerful attack in the game on the fifth hit, with a base power of 960. However, if Rollout misses, then its base power will be reset.
In Generations II and III, Jigglypuff learns Rollout at level 19. It was moved down two levels in Generation IV and it was moved up three levels for Generation V and VI.