i personally believe, which can be backed up by rolling stone mag and the making of star wars, and the numerous scripts published before empire, that star wars itself was only supposed to be an episodic adventure series much like indiana jones and that lucas changed it by making vader lukes father. gary kurtz kinda confirms this by saying they couldve made movies about any number of things featured in star wars. thats where we get the 12 part saga thing, because it was supposed to be more like a serial than what it ended up being.