PK Thunder

PK Thunder is a move found in the Super Smash Bros. series, where it is used by Ness and Lucas. The move is based around the PSI Thunder from the Mother series, though acts differently (as it's a fighting game rather than an RPG). While it's considered a recovery move, it's also unarguably the most challenging to execute if you wish to be launched back onto the stage. To perform it, you must press up on the B button while using either Ness (Super Smash Bros., Melee, and Brawl) or Lucas (Brawl). Following this, the character will shoot out a ball of thunder from his skull, and you'll then be able to guide it around the stage for a short time. This can be used to launch yourself back to the stage, but you can also use it to attack your opponents as well.

To make it a recovery move, you must guide the thunder back to the player while in the air. When it connects, Ness or Lucas will then be shot in the direction the thunder was traveling in.

Ness' PK Thunder is harder to control, though it moves faster, while Lucas' is easier to use as a recovey move.