Improvised weapon

In Assassin's Creed II and Assassin's Creed: Brotherhood, besides the purchasable "regular" weapons, the two-handed weapons such as the spears and halberds, and the heavy weapons,Ezio Auditore can also use improvised weapons.

Assassin's Creed II

 * Hoes
 * Rakes
 * Brooms
 * Pitchforks
 * Fishing poles
 * Violins (used by certain Minstrels, only available during Carnevale)
 * The halves of a broken spear (upper part acts like a sword, lower part like a mace)

Assassin's Creed: Brotherhood

 * Rakes
 * Brooms
 * Mallets
 * Shovels
 * Pickaxes
 * Pitchforks
 * Meat cleavers
 * Fishing poles
 * The halves of a broken spear

Use
All of the improvised weapons can be picked up like any other one-handed weapon, after they are dropped by civilians or guards. Civilians will drop what they are carrying once Ezio gently pushes or runs into them, when a fight starts, or if money is thrown near them. The "weapons" are then discarded once a fight is finished, or once Ezio enters a Free Running sequence.

These "weapons" act mainly as hammers or maces, using the same animations and sound effects. They cannot be kept, and their attacks are sometimes nonsensical. For example, Ezio can slice an enemy's throat with a broom after a grab, exactly the way he does with a sword or with a sharp end of a mace.

Achievements
In Assassin's Creed: Brotherhood, the "Spring Cleaning" achievement can be earned by killing a guard with a broom.

Assassin's Creed II

 * A certain glitch referred to as an "invisible sword" can partially be classified as an improvised weapon. It can be obtained by simply using a spear counter on a two-handed guard, and trying to punch. The invisible sword uses the unarmed slot, swings like a sword when attacking, and allows only instant kills and counters.
 * Some improvised weapons can be kept with a glitch, but will be lost when going to another city or randomly during excessive combat. To do this, you must have an empty sword sheath, which can be achieved by letting a Brute smash your sword or mace away. Afterwards, simply pick up one of the objects listed above, and you may be able to keep them.
 * An alternate way to empty your sword sheath is to go to the Monteriggioni Training Ring and practice "Picking Up Weapons." Ezio's sword will drop out of his scabbard automatically.
 * Guards can also use these improvised weapons, as long as you disarm them and there is no other weapon available. It's easier to make guards use them during DNA Sequence 1, as guards do not yet have weapons.
 * When you rescue Bartolomeo d'Alviano in the memory "Caged Fighter," he uses a broom to fight until he picks up a proper weapon from a fallen guard.
 * The violin sounds like a sword, but acts like a mace.

Assassin's Creed: Brotherhood

 * Although shovels can be used as weaponry in-game, it is most likely that their coding was never finished. In-game, Ezio wields a shovel by the grip one-handed, with the blade pointing behind him instead of forward. Also, when the shovel is swung, the blade and staff clip through Ezio's body. (Tested on PS3, Xbox 360, PC).
 * The “Spring Cleaning” achievement is also awarded when you kill a guard with your dual-wielded pistol, while holding a broom in the other hand.
 * Nearly all improvised weapons can be found in use by civilians in the Delizia di Belriguardo, during the memory "The One Who Got Away."