The robots and A.I programs worldwide have finally turned themselves against humanity, doing whatever they can or have to fight and eradicate humanity. All machines are going rogue, with absolutely no signs of stopping. They are brutal, psychopathic, and most of all, resistant due to their metal bodies. Melee isn't gonna cut it. In addition to using whatever they have to kill humans, they also are causing destruction around the cities. It is incredibly hard to survive.