The Hammer (ハンマー, hanmā) is a close-range item that sends whoever grabs it into a clobbering frenzy for 7.5 seconds. It is one of the most "feared" weapons in the game, as it often KO's a player instantly. It originates from the Mario series, or the original Donkey Kong series. There is a chance in Melee and Brawl that the hammer head will fall off. This forces the character to walk around swinging the hammer stick like normal, but without doing any damage, making them vulnerable to an attack. The hammer head can be picked up and thrown for a very strong projectile attack.
In Melee CPUs tend to evade characters while under effect of a hammer. However, if the the hammer head fall off, CPUs will attack while the player walks around swinging the hammer stick like normal.
Characters cannot do anything except move and single jump while holding the Hammer.
The Hammer does 22% damage every hit.
In Super Smash Bros., it has even more knockback and deals 30%, as well as no worries about the head falling off. Also, the Hammer will glow an orange color just before the time for its use runs out.
When King Dedede grabs the Hammer, he will also swing his own hammer back and forth. In spite of this, he will not do damage if the Hammer head comes off.
Mr Game & Watch and Pit are the only characters can swing the hammer in two frames, but Game & Watch can swing the hammer with one arm.
Explosion-based projectile or thrown item attacks can disrupt someone with a Hammer, such as Link's Bombs or Zelda's Din's Fire, enabling characters with such attacks or items to thwart a foe with a Hammer from afar, and possibly knock it out of their hands. Hammers can also be countered with characters such as Marth and Ike from Brawl or Roy from Melee including Marth. Since Counter always does more damage than the attack it blocked, this can be extremely devastating.
Users can also be knocked off their feet that way, allowing time to quickly hit again. If you manage to be invincible, usually the one granted for re-spawning, you can easily hit the user hard. If near the edge, you can grab them while being completely invulnerable, and throw them off the edge. Anyone wielding a Hammer cannot recover in anyway possible.
Most of the ranged grabs are long enough that with good timing, one can grab someone wielding a Hammer without getting hit by it.
It is possible to (manually) drop a Hammer, but this can only be done while one is getting hit. In Melee, a bonus is awarded for dropping a Hammer this way.
In Brawl, it is possible to make someone 'waste' a Hammer, as the countdown is still active, even when flinching or knocked away and spinning in the air. All one would need to do this is a throwing object, or a projectile that makes its victims knocked back/flinching when hit. Melee pauses the Hammer's countdown when the user is unable to swing, so it is impossible to 'waste' a Hammer in this way in Melee.
Meta Knight's side Special move, Drill Rush, if timed right, can also disrupt the swing of the Hammer while he takes no damage himself.
Kirby's Stone special move is an excellent way to counter this item.
The Hammer gives off vertical knockback.
Since a character is reduced to a single jump, many CPUs accidentally SD, even if they are level 9.
Since Hammers cannot attack below the user, opponents can KO the holder by attacking from underneath if a player jumps. If the opponent isn't KO'ed or knocked off immediately, it is easy to follow up with more attacks while the opponent is on the ground.
In the Subspace Emissary, if a player picks up a hammer, but the head falls off, neither Goombas nor Koopa Troopas cannot be defeated by jumping on their head.
An item that, once grabbed, makes you swing nonstop. It's a powerful attack item that does terrific damage and sends opponents sailing. Once in a great while, the hammer's head will fall off, leaving you nothing but the handle. Of course, you can't tell whether the head is securely fastened just by looking. Hammer heads that fall off can be picked up and thrown as weapons.