Force Lightning was a power to shoot multiple bolts of lightning user's fingertips and strike into any nearby enemies. More powerful users can make it so powerful that a single shot 'jumps' from enemy to enemy- which could render an entire squad of Stormtrooper dead in mere seconds. This force ability is usually used by dark side users.
A more powerful version was used by some dark side practitioners also known as 'Sith Scorcher' because of its use by the Sith. The lightning in this attack was cast from two hands and spread out extremely quickly to kill nearby groups of enemies- who would be unable to last long against the intensity of the blast.
Some well known users of force lightning are:
This move is activated in the game by certain buttons on console controls.
PS2/PS3/PSP: O once for ordinary lightning and twice for Sith Scorcher.
Wii: C once for ordinary lightning and twice for Sith Scorcher
Xbox 360: Y once for ordinary lighting.