The Fan (はりせん, harisen) has been used in three of the four games. It has very weak rapid attacks and can be an effective KOing projectile when thrown.
Its ability to suck in opponents combined with its rapid rate of fire makes it incredibly easy for one character to trap another in a flurry of rapid fan attacks. Trapping an opponent in this rapid flurry of attacks is referred to as 'fan-locking' the opponent, since it is very difficult to escape and often 'locks' them in a state of helplessness.
In Brawl, the Fan is given paper-like properties and floats to the ground if thrown into the air.
When A is tapped, it does between 1-2% damage.
When fully charged, it does between 7-13% damage and breaks any shield.
When dropped, it does 3% damage.
When thrown at the opponent, it does between 9-12% damage with some strong knockback upwards.
Due to its high attack speed in Brawl, it is possible to trap a character into successive hits until they reach 999% damage.
The Fan can be swung so rapidly that it leaves opponents unable to counterattack. It is, however, an exceedingly weak weapon. Despite this shortcoming, the Fan is quite effective as a shield breaker, and it works well at disrupting an enemy's equilibrium. Throw the fan to send your foe bouncing straight up into the sky.
An item made by taking thick paper, folding it accordion-style, taping one end, and fanning out the other. It's mainly used as a comedic prop by comedians from Osaka and the Kansai region of Japan. Why it's in Smash Bros. is a mystery. Grab this unique item and whack foes to turn them in the opposite direction. Throw a fan at a foe, and that character will fly straight up.
The Fan appears as an item in Mario Kart Arcade GP.
The Fan is effectively abused by smaller characters, due to the their size. The Fan serves as an extension of the characters body, lengthening the range, and eventually, inviting 1 or 2 foes into the area of effect of the Fan. The speed is also abused because it can effectively cancel out the foe's opportunity to escape.
The Fan is an incredibly effective item in Multi-Man Melee and Brawl when thrown, as it will always KO the enemy when hit and will bounce back into the air, often starting a chain of opponents being KO'd by the flying Fan.
The fan is the only item that has appeared in the first three Smash Bros. games, but not in 3DS/Wii U.