In the late 20th to early 21st century, the United States government develops a Command and Control computer system known as Skynet. Skynet is an artificial intelligence that eventually becomes sapient and decides to wipe out humanity. To do this, Skynet starts a nuclear war, resulting in the destruction of civilization. It then deploys an army of robots to mop up the survivors. A resistance movement led by John Connor succeeds in defeating Skynet. In an attempt to prevent its defeat retroactively, Skynet sends various Terminators back through time to assassinate John Connor and his mother Sarah (before his birth), but the resistance also sends various agents to stop them.
A terminator is a robot designed to infiltrate human strongholds by impersonating a human soldier or civilian. Any model of terminator has superhuman strength and durability. They have been seen to smash through safety glass easily or bash through heavy doors with effort. They are highly resistant to small arms fire, although repeated hits from heavy rounds (like point-blank blasts from a shotgun) will briefly incapacitate them. All known models were capable of accurately mimicking any human voice they had heard.
Skynet developed several "series" of terminator:
- T-600 Series: These terminators were steel alloy skeletons covered in a rubber skin to allow them to get close to human targets. The human resistance were able to identify them without much difficulty, resulting in poor field performance.
- T-800 Series: These terminators used cloned human tissue to cover the robotic skeleton with living flesh, resulting in a nearly perfect physical disguise: muscle, blood, skin, hair, bad breath... everything. Consequently, an 800-series terminator is technically a cyborg. Introduced late in the war against humanity, they were highly successful at infiltrating human settlements until people realized that dogs could distinguish them from humans (presumably by smell). The 800 series model 101 is the "Arnold".
- T-1000 Prototype: The T-1000 was a unique prototype composed of a mimetic poly-alloy that the terminator AI could freely reshape to mimic virtually anything of similar size, limited only by the need to physically contact the object it sought to mimic. The T-1000 could also form hard metal blades, spikes, and bludgeons from its mass for use in close combat. Even when severely damaged it could reform itself in a few moments, making it much harder to destroy than earlier models; only extreme temperatures seriously affected it.
- T-X Prototype: A combination of both a solid endo-skeleton and a poly-alloy covering, the T-X combined some of the shape-changing ability of the T-1000 with a solid platform for mounting built-in weaponry. The T-X included a flame thrower and a directed-energy weapon in its arms. It also had special technology for taking control of other machinery, allowing it to remotely operate vehicles and commandeer other robots or computers for its purposes. It could change its appearance to mimic different human beings, but it could not adopt a non-human form the way the T-1000 could.
- The Terminator (1984): Skynet sends a T-800 back through time assassinate Sarah Connor, mother of the resistance leader who is defeating it in the future. Capturing the same facility, John Connor sends one of his soldiers into the past to intercept the Terminator and protect Sarah.
- Terminator II: Judgement Day (1991): Hedging its bets, Skynet had actually sent two Terminators into the past. The second was the T-1000 prototype, sent to kill John Connor while he was still a child. John Connor also sent a bodyguard to intercept the assassin, this time a reprogrammed T-800.
- Terminator III: Rise of the Machines (2003): The events of T2 delayed the startup of Skynet and the ensuing war but failed to prevent either. Nonetheless, Skynet was still destined to eventually lose the war if it couldn't eliminate John Connor before the war started. Thus, a T-X prototype was sent back through time, and a T-850 (a T-800 with a power supply upgrade) was sent back to stop it.
- Terminator Salvation (2009): Set in the future during the war between Skynet and the human resistance, the outcome of the war hinges upon the actions of a mysterious man from the past.
The Sarah Connor Chronicles depicts events in the lives of Sarah Connor, John, and a Terminator sent back to guard them, which they name Cameron. This series ignores the events of T3, picking up the story after Terminator 2.
Terminators in Debates
"What would Character X do if hunted by a Terminator?" is a common debate topic.
The Terminator movies appear to flip-flop on whether time travelers can change history.The genocidal supercomputer Skynet clearly thinks changing history is possible; otherwise, it would not have attempted a retroactive assassination to achieve victory.
In The Terminator, resistance fighter Reese was also told that "the future is not set", indicating that Skynet's plan could potentially succeed, yet by the end, the incident seems to have set up events to run exactly has Reese remembers them from his time.
Terminator 2 ends with what appears to be the defeat of Skynet when the heroes destroy the Cyberdyne Systems computer facility developing its AI technology.
Terminator 3, however, reveals that the construction of Skynet was merely delayed (presumably Cyberdyne had off-site backups). The T-850 Terminator claims that the "Judgement Day" war is impossible to prevent.