Tumbling (or DamageFall internally in Melee and Brawl files) is an airborne state that a character may enter after being hit or pushed in certain ways; for example, edge slipping can cause a character to tumble. A tumbling character can easily be identified by their defensive, rotating animation. Characters may tumble after being hit through the air by an attack with strong enough knockback, footstooled in midair, pushed off a ledge, after walking off an edge while carrying a crate or other heavy item, or by sliding off of an edge while shielding.
In the original Super Smash Bros., the minimum knockback that must be inflicted to cause tumbling is roughly 60 units and in later games, this would be increased to around 80 units.
The benefit from tumble compared to non tumble hitstun varies from game to game. In Smash 64 and Melee, tumble is not beneficial since it leaves the opponent in more hitstun than a non tumble state. In Brawl however, tumble leaves the opponent at a bigger advantage than a non tumble state. Tumble enables the opponent to perform hitstun cancelling (and subsequently momentum cancelling) which is not possible in a non tumble state. It also enables the opponent to DI which they cannot do from non tumble hitstun starting from Brawl and the gravity penalty also now takes effect once the opponent enters tumble. This enables characters with high gravity (such as Fox) to fly much higher once they enter tumble preventing chain grabs and strings to connect against them. In Smash 4, hitstun cancelling's effect was greatly reduced making tumble less beneficial than in Brawl although it still has the same advantages besides hitstun cancelling. With Ultimate homogenising the effect of falling speed and gravity against moves with an angle between 70°-110°, tumble has become less beneficial again although it still enables the opponent to DI.
Actions possible while tumbling
If tumbling characters hit the ground without teching, they will land into a lying position and must then use a floor recovery. Characters undergo a flopping animation upon hitting the ground before they can use their floor recovery, leaving them vulnerable for a short while.
The tumbling animation is used after a shield jump, though no action can be performed during this time. It is also used at the end of Olimar's Final Smash (after emerging from the Hocotate Ship), but Olimar will be unable to do anything other than move horizontally.
Reeling (or DamageFlyRoll) is a state similar to hitstun, except the characters enter a helix motion. In all games, this only occurs once the character is at 100% or more, and occurs 30% of the time. During this state, characters cannot do anything except DI, or tech if they come into contact with a wall or ceiling. Once the knockback diminishes and the character slows down, reeling ends and tumbling begins. Teching is useful for characters with high damage, or during Sudden Death matches, since being attacked under such circumstances often causes reeling. Reeling can also occur after using the Bullet Bill; however, it does not end naturally, and can be canceled by using an aerial attack or air dodge, or landing.
Because of the character's two-dimensional nature, Mr. Game & Watch has a unique reeling animation. Instead of spinning, he repeatedly cartwheels as he is launched. Steve also has a unique reeling animation which is just his tumbling animation with his body oriented in the direction of his knockback.
In Smash 4, the reeling animation does not allow characters to tech on the floor until the hitstun cancel window starts. However, it does allow Cloud to tech walls and ceilings if he is hit near the apex of Climhazzard, where teching is otherwise impossible.