Sword Beam

The Sword Beam is a maneuver often utilized by Link wherein, when he is at full health, an attack with his sword will result in a beam of light streaking out and striking anything in its path. It is useful for when one does not wish to engage in close quarters combat or use ammunition like arrows. At times, it can be utilized with any blade; at others, only special blades like the Master Sword will create a Sword Beam when swung. This depends on the game.

There are two known variations, the first being a straight beam that is actually shaped like the blade of the sword it springs from. This is the most common variation, appearing in The Legend of Zelda, The Adventure of Link, Link's Awakening, Oracle of Seasons, Oracle of Ages, The Minish Cap, and Phantom Hourglass.

The other, rarer variation, appearing like a swirl of sparkles continually traveling along their circular path even as the center of that circle moves in a straight line, has thus far only appeared in A Link to the Past, Four Swords and in The Minish Cap after you get all four elements.

A related maneuver is known as the Peril Beam, which works exactly the same, except the beam is shot out while only one Heart Container remains filled, not while at full health. This variation is only found in The Minish Cap.

Trivia

 * Thus far, the Sword Beam has only appeared in the 2D Zelda games, with one possible exception. The sword beam was supposedly going to be in Ocarina of Time, but it was scrapped; the discs of light released from Fierce Deity Link's sword in Majora's Mask are suspiciously similar to the Sword Beam, and possibly the move's sole 3D appearance.
 * Interestingly, even though the Sword Beam appears in the familiar blade-shaped variation in The Minish Cap, the Four Sword's curse-breaking maneuver is visually identical to the swirl variation despite working completely differently.
 * In TV series, the Sword Beam is the only attack which Link performs with his sword, other than using it to parry. Presumably this is because at the time cartoons could not depict graphic weapon violence, so a magic beam was seen as a softer alternative.
 * The sword beam that was in the pre-release development period of Legend of Zelda Ocarina of Time can be found in the Ocarina of Time Debug ROM's gameplay_keep.
 * It is possible that the sword beam may have been acquired at the unicorn fountain because they were both removed from the final game and also the sword beam seems as if it would use magic which would make sense if it were learned at the unicorn fountain.