The Hammer (ハンマー, Hammer) is a close-range item that appears in all Super Smash Bros. games. Upon being grabbed by any player, it sends them into a unique state that inflicts significant damage and knockback.
The hammer comes from the arcade game Donkey Kong. In Donkey Kong, when Mario obtains the hammer, he is unable to stop swinging until the hammer disappears. He also is unable to climb ladders while swinging the hammer. The hammer can be used to destroy barrels that are being rolled down towards Mario, and can be used against other enemies.
Contrary to its depiction in the Super Smash Bros. series, the Hammer's head cannot fall off in the game, nor can it otherwise malfunction.
Upon picking up the Hammer, characters enter a unique state for eight seconds; they will constantly swing the hammer back and forth, and will be unable to midair jump, use any other attacks, or defend. The Hammer also cannot be manually dropped unless the user has been sent into a state of tumbling. The Hammer deals about 22% per hit, and it also deals extremely high vertical knockback, potentially KOing opponents at low percentages; the effects of the Hammer are even more formidable in Super Smash Bros., where the Hammer instead does 30% damage with even more knockback. The Hammer can also "chain" into itself, doing 60% and likely KOing the opponent. The Hammer disappears after seven seconds.
The Hammer, however, limits the user's options, and particularly careful hitbox placement by other characters can potentially interrupt the wielder. Counters are especially powerful against Hammers since most of them deal more damage for any attack they counter. As the wielder of the hammer cannot use special moves or midair jump, sending an opponent off a ledge while they swing the Hammer can effectively KO them unless they can somehow drop the Hammer. In Brawl and Smash 4, the Hammer also operates on a "timer"; if a character wielding the Hammer is constantly hit so that they cannot swing the item, the timer will still count down, potentially getting rid of the Hammer before they can properly use it.
The Hammer is also an item in Smash Tour: when its trophy is selected, the user starts the battle wielding a Hammer.
Starting in Melee, there is a 12.5% chance (one out of eight) of the head of the Hammer falling off as it is picked up, after which the item becomes functionally useless, though the wielder will continue to swing the handle for as long as they would with a normal hammer. The Hammer Head itself can be picked up and thrown as a powerful item, dealing 35% when smash thrown.
If the Hammer Head falls off, then the player is rewarded with the Headless Hammer bonus, worth 2500 points. This bonus only appears in Melee.
Damage for Hammer Head