The Beam Sword (ビームソード,Bīmu Sōdo?) is a long-range clobbering item. Available and appearing from within the Super Smash Bros. series, it can be wielded and charged for melee attacks or can even be thrown. The length of the Beam Sword in Melee and Brawl changes depending on the character wielding it and the intensity of the attack performed with the beam sword's smash attack generally having the longest range of all beam sword strikes. In Melee and Brawl, it is possible for Peach to pull out a Beam Sword with her Vegetable attack, but this is incredibly rare.
In the original Japanese versions of Super Smash Bros and Super Smash Bros. Melee, the Beam Sword sounded very similar to a Lightsaber from the Star Wars franchise; in Super Smash Bros. Brawl, the sound effects have been kept for all versions.
When held by either Marth, Ike, Pit, or Roy, the smash attack is a double smash; the character slashes with his regular sword and then takes a second stronger swipe with the Beam Sword.
When held by Captain Falcon, the forward smash is a two part attack with a weak hit low followed by a strong upwards hit that knocks opponents skyward.
When held by Sheik, the forward smash is a very quick double hit, both upwards, with the first slightly stronger than the second.
When held by Mewtwo, a dashing A attack is around 5 spinning hits (around 20 damage). When he smashes with it, he slices it downwards.
When held by the Ice Climbers the one holding the beam sword will do a beam sword attack while the other will hit with their hammer.
It also appears in Samus' Screw attack or anyone who has the Screw Attack badge.
"With its distinctive glowing blade, the Beam Sword is eye-catching and lethal. At first, the blade is about the size of a short sword, but the length changes depending on who wields it. The blade also lengthens in direct proportion to the power of an attack, so it reaches its maximum size when swung as a smash attack."
A sword with a blade of glowing energy. The length of the blade changes depending on the fighting spirit of the wielder. It has four attacks: a standard attack, a strong side attack, a side smash attack, and a dash attack. When doing a side smash attack, the beam sword's blade grows to three times its normal length--that's the best reach of all battering weapons.
Sakurai stated that "for the first time in the Smash series, Beam Swords will feature graduated colors".
It also appears the Beam Sword will strike with combos for neutral slashes