 A core feature of Shadow of Mordor is the Nemesis system . The game tracks a number of specially tagged Uruks as part of Sauron 's armies , who will lead the other Uruks in battle . Defeating these leaders will help to weaken Sauron 's army , and these leaders will drop a rune which the player can install on Talion 's weapons to provide additional buffs in battle . Alternatively , being killed by a leader will cause the current mission to be cancelled and the player returned to a safe point to continue exploring , and the leader will gain additional power , making him more difficult to defeat in the next encounter . If the procedurally generated Orcs survive an encounter with Talion , they will also be promoted . Further , such deaths are tracked through online servers , and the player 's friends on the various network services will be notified of this death and be offered the chance to accept the Vendetta mission , and carry out exact revenge on the Uruk . If the mission is successful the game will give rewards to both the original player and the victorious friend . 
