Why can there only be two sith?

Because they all killed each other.

The Rule of Two.

“Two there should be; no more, no less. One to embody power, the other to crave it.”

Three shall be the number of the counting, and the number of the counting shall be three. Four shalt thou not count, nor shalt thou count to two, excepting that thou then proceed to three. Five is right out!

Because 3 sith’s a crowd.

You’ll notice that at many times, even just within the films, The Rule of Two is broken. Sidious was always a bit of a d*ck though.

Because any more would be sithing all over each other.

Because There can be only one was already being used by Highlanders.

@robmandu So I guess kids are out of the question then?

Okay did you SEE the amount of effort it took for Sidious to hide, remain undercover AND train Darth Maul? This , of course, being after he killed his own master (Plagus). All while forming a giant empire and preparing for the ‘chosen one’. And then Maul got his ass kicked after accomplishing pretty much nothing except killing Qui Gon (big whoop).

Then he has to convert Anakin to the dark side, turn three factions against each other, create an intergalactic coup, simultaneously kill almost all the Jedi, retain control of his new empire and build a giant planet-killing space station as Darth Vader emerges. Finally, he has to quell an all-out rebellion while (secretly even to audiences) helping Vader train Starkiller and then build ANOTHER giant planet-killing space station.

Yeah, no wonder he looked all fugly. I’m amazed there’s even ONE Sith, how the hell could anyone have time to train?

There were times when their were many Sith, whole armies and orders. The whole (summary of the) story is in the Wookipedia link that @robmandu has provided.

The answer depends on if you want the movie-based reason, or the extended universe [books, etc.] reason.

The answer lies with Jar Jar Binks.

@J0E Die.

@rangerr If you strike me down I shall become more powerful than you can possibly imagine.

@J0E Great, kid. Don’t get cocky.

@gambitking I can imagine Sidious saying something like this:

“Plagus, you know how much I love watching you work, but I’ve got to create an intergalactic coup, simultaneously kill almost all the Jedi, retain control of my new empire and build a giant planet-killing space station. I’m swamped.

And Plagus might answer:
“Get some rest. If you haven’t got your health, then you haven’t got anything.

:-)

@Dr_Dredd Seeee….TOTALLY, there’s just no way to justify the outsourcing of additional Sith

@gambitking “Okay did you SEE the amount of effort it took for Sidious to hide, remain undercover AND train Darth Maul? This , of course, being after he killed his own master (Plagus)”

Are you implying that Sidious started training Maul AFTER Plagueis was dead?

@rangerr I don’t think there’s any implying going on. It looks like a statement to me

what great answers!

Thanks for the great answers

Still waiting for @gambitking‘s reply.