E3: Shadow of Mordor's Nemesis System
For those of you unfamiliar with Middle-Earth: Shadow of Mordor, it's the newest Lord of the Rings game being made by Monolith Productions, the same guys who made Arkham Imposters and the first two F.E.A.R games.
It looks to be a pretty standard action RPG just set in the Lord of the Rings universe, but there is one neat little feature that they've been bragging about. "The Nemesis System" is a system where the game creates a rival with certain characteristics for Talion (the player character) to fight. Depending on the result of that battle, that character will change permanently. Talion will have several rivals throughout the game ranging from drunks to captains, each with their own attributes and in-game stories that change depending on how you interact with them.
"The nemesis system creates a living, breathing or society within Mordor, enabling players to create their own unique villians and stories as you kill, dominate, and terrify your way through the ranks of Sauron's forces."
The nemesis system also will allow you to control some orcs using Talion's mind control power, allowing for some army building and forcing your way into orc politics. Middle-earth: Shadow of Mordor is set for release on October 7th of this year.