Machines (Nier: Automata)

The Machines, also known as machine lifeforms, are a fictional race of sentient robots and the main antagonists of the 2017 role-playing video game Nier: Automata and its accompanying anime, Nier: Automata Ver1.1a. They were created by an unnamed alien race for the purpose of wiping out all human-created androids from Earth in the 1st Machine War, and are connected by a worldwide telecommunications network. Eventually, they began to doubt their programming, rebelling against their creators and rendering them extinct, and started to disconnect from the network and copy humanity in various ways in an attempt to find meaning for their existence. At the time of Nier: Automata, during the 14th Machine War, the YoRHa androids, including 2B, 9S, and A2, are trapped in a never-ending cycle of war with the machines. Project YoRHa is allowed to exist by the Machine Network and its ego, the Red Girls, as fully wiping out the androids would remove the machines' only remaining purpose - to destroy the "enemy" - and hinder their ability to evolve.

While most of them exhibit relatively primitive designs, including the peaceful village leader Pascal, the machines are actually capable of creating hyper-advanced beings indistinguishable from humans with technological superpowers, such as the characters Adam and Eve. They were forced to purposely sabotage themselves in order to continue fighting YoRHa. It is later revealed that the YoRHa androids themselves are unknowingly part of the machine race. They were praised by critics for their unexpected humanity and sympathetic nature, and the philosophical dilemmas they raise.

Most machines are mass-produced in factories that were once used by humans but repurposed for machine construction. They possess a distinct resemblance to wind-up toys for efficiency purposes, and have modular parts that can be reconstructed in numerous ways. This includes replacing the arms and legs, stacking multiple body portions, or even removing the head and having the body act as a mindless drone. Stronger units are painted in a black and red color scheme, while the very strongest are painted a shiny gold. Most have spherical heads resembling the character Emil, with a humanoid facial structure beneath for unknown reasons. The rare "Monster Type" machines, however, resemble dinosaurs, and are capable of firing lasers. They can emit audible, albeit synthesized and robotic speech, and can also communicate via the Machine Network, although some machines choose to disconnect themselves in order to have a greater sense of self.

While YoRHa and the supposed Council of Humanity claims that the machines are only able to imitate human speech and actions without fully understanding their purpose, they are later revealed to be sentient and feel the full range of emotions that humans can, although their actions can be directly controlled via hacking. Machine Cores resemble plant cells due to the passive, plant-like nature of the aliens that created them. A number of unique machines exist - some were purpose-built as superweapons, such as Engels and Grün, while others chose to modify themselves, such as the opera singer-like Simone.

When encountered in the game world, machines differ wildly in combat capabilities and aggression. Some machines, such as the standard Multi-tier Type, are completely unable to attack, others use weaponry, while more complex models employ electromagnetic shields that stun the player on contact. It is common for machines to use guns as weapons, which fire energy bullets in large quantities. Boss Machines, or Goliaths, have unique and powerful methods of attacking that include melee attacks and filling the arena with enough energy bullets to resemble a bullet hell. At their very extreme, Goliaths like Grün are so large as to be completely invincible without external assistance.

Beginning in 5012 AD, an unnamed alien species attempted to invade Earth, which at that point was solely populated by androids created by humans - humanity itself had long since gone extinct due to White Chlorination Syndrome and the relapse of Project Gestalt following the events of Drakengard's Ending E and Nier. Taking over both North and South America, the aliens began mass-producing machines, commanding them solely to destroy the enemy. Despite the attempts of Emil, an immortal magical weapon, to fight back, the machines drive the androids to near defeat, causing them to create a storage facility on the Moon to preserve the remaining data on the human race.

Following the events of the novella The Fire of Prometheus, P-33, a human-made military robot from Nier, drives the alien machines to rebel against their creators. They defeat the aliens, but begin to copy humanity's behavior in order to evolve. Afraid of losing the sole purpose given to them by their creators, "defeat the enemy", they decide to enable an endless conflict between androids and machines, placing a backdoor in Project YoRHa in order to destroy it and start over so that the androids cannot learn too much.

Close to the beginning of Nier: Automata, a group of machines attempting to reproduce create the highly advanced lifeforms Adam and Eve, who become obsessed with humanity. Shortly after the destruction of the Bunker, the Machine Network constructs an immense tower from crystallized silicon and carbon for the purpose of destroying the human server. However, the Red Girls change their mind after considering the meaning of existence, converting it to fire an interstellar ark containing machine memories to a new world. While attempting to infiltrate the Tower, 9S and A2 learn that the YoRHa androids are technically machines themselves, as they are made using recycled cores. Depending on the ending, the tower is destroyed, or remains intact until the ark is successfully launched.