In Curse of the Black PearlThe Curse of the Black Pearl, Jack hints that he's planning on exchanging Will Turner for the Black Pearl to Barbossa for the Black Pearl.
Will catches on to this and knocks him out.
Was this actually Jack's plan all along? It's rather evil considering Jack appears to have some morals throughout the movie. I'm also not sure Barbossa would even give him the ship at all.
Maybe it was all a ruse, and if Will hadn't knocked him out we might have seen some other, less evil, plan unfold?