The Sith in KotOR were a large, militaristic force. They continued to be that way until Darth Bane instituted the Order of Two. That order, meant to preserve the Sith and thier ideals, stated that there would be only one master, and and apprentice, as well as a few dark side adepts which would aspire to be an apprentice when the current one succeeds his master. If you've played KotOR, the Sith are the dudes that run around in the silver armor everywhere. They're not all force users, and most are just normal military men. If you haven't played KotOR, first off, wtf is wrong with you? and second, play it. Buy an Xbox 360 if you have to (only $200 now) and play both games. The story they tell is awesome, though the gameplay is a bit... unpolished. It's like Mass Effect or Jade Empire, only slightly slower paced and not as fun... but for a Star Wars fan, it's a blast.