Zap Jump
Zap Jumping is an advanced technique that doubles the height of Lucas's second jump. It was discovered by Christopher Daniel Winans, though it is unclear exactly what the term "Zap" refers to.
To execute this boost, you must use PK Fire within one frame of his double jump, essentially pressing them at virtually the same time (one sixtieth of a second delay). Lucas's air jump propels him by an upward force (like most characters), but for some reason the ascent is hindered by a downward force right after this, which is apparently negated by the side special.
The bolt of fire is released about halfway through the jump, and combined with B-Sticking and Magnet Pull, Zap Jumping allows for an impressive recovery. Due to the obscure nature of jumping immediately after a special, along with the awkward input layout on most controllers: it is advisable to change the controls to a more congruent assignment; the L or R button, for example.
PK Jump & Firebound
Ness is also strangely affected by using PK Fire with his second jump. When the two move are uses simultaneously, he will shoot forward and slightly higher. This makes for a great approach and extends the special considerably, and can also be used for recovery, acting as a barrier against opponents edgeguarding from below.
A variation of this maneuver, known as the Firebound, combines the mechanics of the PK Jump and B-Sticking. By pressing the B-stick backward while holding forward and double jumping, you will shoot backward; a defensive maneuver.
Videos
Lucas' Zap Jump, and other
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Ness' PK Jump
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