is

[Harley]

is this a stand alone expantion or do i need to original game first

[Harley]

but its best to play the original first?

[Umeboshi]

Well... kinda. As far as the story goes, this game is a direct sequel to the first one. It's a simple story though, if you must know: in Jedi Knight, Kyle becomes a Jedi, defeats the Sith, and swears to protect the Valley of the Jedi and keep its location secret. That's it.