Force Palm
For Lucario's Force Palm, it thrusts its hands forward, releasing a wave of aura. If used at close range, it becomes a quick grab and punch attack. The damage delt out (and distance), like Lucario's other attacks, depend on the damage Lucario has taken. It is a relativly slow move and tends to leave Lucario open to atacks by others. It is a good way to stop a knocked off character from geting onto the stage again (if you have a mid-high damage %)
In the games, Force Palm is a standard physical attack, learnable by Lucario. It is not an energy-based special attack in-game, but rather a sideways slapping sort of motion with the palm facing forward. It is used by the Lucario owned by Riley, the in-game character that gives you a Riolu egg, and the only way to obtain a Lucario in Diamond and Pearl.
