Hammer
Hammers are items commonly used as weapons throughout the Marioverse. They first appeared in Donkey Kong, in which they were used to smash barrels and enemies. Hammers are usually thrown by the Hammer Bros. and other enemies. However, Mario and Luigi, the heroes of the Mushroom Kingdom, have been known to effectively wield Hammers in combat. In the Paper Mario and Mario & Luigi sub-series, Hammer attacks are used as a counterpart to Jump attacks. Some enemies can not be damaged by Jump attacks, requiring the Mario Bros. to use their Hammers instead.
Donkey Kong
In Donkey Kong Mario could destroy both the barrels thrown by Donkey Kong and the Fireballs created from the flaiming oil barrels. Mario is not invincible when using it, however. If attacked from the back, he will still lose a life. Mario also cannot climb or jump while wielding the Hammer.
Super Mario Bros. series
Super Mario Bros. showed the Hammer being used by Hammer Bros. These Hammers were extremely hard to dodge, especially when the Hammer Bros. appeared in pairs. They seem to have an unlimited supply of Hammers, just like Lakitus and their Spiny Eggs. Mario and Luigi could wield an unlimited supply of Hammers by donning the Hammer Bros.' Suit in Super Mario Bros. 3. When wearing the suit, they gain all the characteristics and abilities of the Hammer Bros.
Super Mario RPG: Legend of the Seven Stars
In Super Mario RPG: Legend of the Seven Stars, Mario's first (and weakest) weapon was called the Hammer. Mario received the Hammer after he beat the Hammer Bros. blocking the exit of Mushroom Way (In fact, the weapon has their insignia on it.). The mighty plumber used this weapon to pound enemies, at least until he found the Noknok Shell. When equipped, the weapon adds ten attack points to Mario’s attack rating.
Paper Mario series
In Paper Mario and Paper Mario: The Thousand-Year Door, Mario receives not only the Hammer, but the Super Hammer and Ultra Hammer as he progresses through the adventure. Paper Mario and Paper Mario: The Thousand-Year Door gave the Hammer much more focus and was the only way to defeat certain enemies. In battle, Jump attacks couldn't work on every single enemy, so the Hammer was introduced as an alternative. It worked on all enemies and was always stacked damage, proving useful against fire, spiked, and high defense enemies. There was one flaw to it though; it didn't work against air-bound and ceiling attached enemies. With a special badge, namely Hammer Throwit could be used on all enemies.
Outside of battle, the Hammer can be used to break certain big blocks. The type of block Mario could break depended on what type of Hammer he had. The move, Spin Hammer was also introduced in Paper Mario: The Thousand-Year Door as a way to destroy even bigger blocks. However, the Red Block was removed from Paper Mario: The Thousand-Year Door.
Mario & Luigi series
The Hammer was used by the Mario Bros. in Mario & Luigi: Superstar Saga and Mario & Luigi: Partners in Time. However, the move wasn't used as much compared to the Paper Mario series. Unlike the Paper Mario series battle system, each Hammer upgrade didn't affect in-battle damage and attack power.
In Mario & Luigi: Superstar Saga, Hammers were crafted by the Hammerhead Bros. out of Hoohoo blocks. They are used to smash rocks (instead of blocks) in Mario and Luigi's path, defeat enemies in battle, and hit buttons and switches. They can later be upgraded to Super Hammers and, ultimately, Ultra Hammers. They can also be used to flatten Mario so he can fit into small spaces and to bury Luigi so he can travel under gates.
In Mario & Luigi: Partners in Time, two Hammers are given to Baby Mario and Baby Luigi by the L33t Hamm3r Broz. These weapons can be used to tunnel underground (a useful technique when searching for Beans) and hit switches. In battle, Baby Mario and Baby Luigi can use their hammers to attack enemies (and potentially stun them, rendering a monster inactive for a few turns).
Mario vs. Donkey Kong 2: March of the Minis
Hammers make an apperance in Mario vs. Donkey Kong 2: March of the Minis'. If a Mini-Mario touched one, they would start slamming the Hammer up and down, defeating any enemy nearby. The Hammer music from the original Donkey Kong would play also.
Super Smash Bros. series
Hammers are a powerful item in Super Smash Bros. and Super Smash Bros. Melee.
