No two players' experience will be the same in the upcoming Lord of the Rings game, Middle-Earth: Shadow of Mordor.
In a recent preview, I explained how that is and how the Nemesis system fits into that. If you missed it, you can use the Nemesis system to target various warchiefs and have their bodyguards turn against them, thereby shifting the power struggle in a way that's more advantageous to you. Commanding the bodyguard to do so successfully will leave that entire army at your disposal. It's how you will eventually take on Sauron with any hope to live to tell the tale.