Vader doesnt know about the 2-sith rule

From the ESB script:

***

EMPEROR: The Force is strong with him. The son of Skywalker must not become a Jedi.

VADER: If he could be turned, he would become a powerful ally.

EMPEROR: Yes. Yes. He would be a great asset. Can it be done?

VADER: He will join us or die, my master.

***

OK, so what happened to the 2-sith rule? Apprently, when Lucas was making ESB, he wasn't sure about the details of Sith policy. This dialog indicates that both the Emperor and Vader were willing to accept Luke into their party; at least that's what they are admitting to eachother. But later on, it's obvious that Vader is planning a coup, and that's why he's interested in Luke. In ROTJ, the situation is reversed, and as indicated by a recent poster, it begs the question, 'what the hell was Vader thinking?' He went along with the Emperor's plans, like an anemic turtle, knowing full well that the Emperor wanted him out of the picture. All he had to do was let Luke get the first hit on old Palpy, sitting in the chair and smiling pretty. The counter argument, of course, is that Vader accepted the fact that Luke would not turn, so he really was trying to kill his son... what an evil bastard. But I digress. The above leads me to believe that the 2-sith rule is not a strict dogma, but simply the nature of the beast as Lucas' see's(saw) it. Evil is mythically notorious for turning on itself. Hence the 2-sith rule is simply a de- facto standard between minions of evil: one recruits a third to kill the other, leaving at most 2. If one remains, then he simply recruits a disciple, and we're back at the happy number. But what, oh what, would happen if all three die? Inquiring minds want to know.

<snipped>

There are still dark jedi.

I think both the Emperor and Anakin had dreams of teaming up with Luke and doing each other in though.

Deborah Proctor

Vader was in conflict. as he stated he must obey his master, but he also loved his son.

I think he new about the 2 sith rule and was buying time until they could conquer the Emperor and take control.

Of course he does. He wants to rule the whole galaxy. He doesn't want to fight a ton of other Sith Lords and have the galaxy divided between

In such a big galaxy, it would appear to be a lot more logical to have many Dark Sith Lords and there underlings/apprentice, each with there own agenda. After all . Not all of them would want to rule the galaxy. So the 2 sith rule doesn't make sence on a galactic scale.

The 2-sith thing has made this aspect of the original much more interesting. I wonder if Lucas has commented on it.

Actially they would ALL want to rule the galaxy, or the largest single chunk of it. It is the nature of the Sith. And they wold all build Death Stars, Planet Devistoators, Star Crushers, Galaxy Guns, Doomsday Machines, ect to that end.