The Sentinels are designed to hunt down mutants by specifically targeting the mutant X-gene. Built out of a space-age polymer, the Sentinel Mark I model measured 18 feet tall and weighed approximately 4,800 lbs, being equipped with Dual Trask 873K energy blasters for armament support, and was able to achieve Mach 0.9 through the addition of Two G302-TI-99 enhanced performance ion thrusters. Each Sentinel was also fitted with a Mutant Detection Device, capable of distinguishing between mutant and human individuals and specifically targeting those with the mutant X-gene.
In addition to these specifics, Bolivar Trask stated the Sentinels carry the aeronautic capabilities of a Harrier jet, armed with guns that can fire off more than 2000 rounds per minute of thermoceramic ammunition. Between 1973 and 1996, Trask Industries produced 8732 Sentinels for the governments of the United States, China, Russia, Israel, Saudi Arabia, France, India and the United Kingdom.
As Trask Industries advanced the template for the Sentinels over the years from Mark I to Mark IX, the Sentinels became highly weaponized and largely changed in physical design, becoming jet-black in color with huge, heat emitters. They also became, as a result of Trask Industries extrapolating Mystique's mutant ability, able to counter mutant abilities with complementary attacks that would render them powerless.
In 1973, Bolivar Trask pitches the Sentinels to Congress but they decline him so he pitches them to foreign powers. Mystique shoots Trask in revenge for the murders he has committed of mutants while creating the Sentinels, not knowing the future this will create. Trask's death only made him a martyr for the Anti-Mutant Movement, and Nixon approved of the Sentinel Program.
A Sentinel briefly appears during a training session in the Danger Room. After Colossus launches Wolverine into the air, he cuts off the head of the Sentinel with his claws. The head falls through the air and lands in front of the X-Men. It is later revealed to have been an interactive hologram.
In a dystopian 2023, the Sentinels hunt down mutants in a war that has also wiped out most of humanity and left only the "worst" of humanity left to rule the world. These Sentinels have been created using Mystique's DNA which gives them the ability to adapt to mutant powers and even use some. The surviving X-Men gather in a monastery in China for a last stand against the Sentinels while Shadowcat uses her powers to project Wolverine's consciousness back to 1973 to try to change the future where the Sentinels were created. In a final battle, all the X-Men fall to the Sentinels, unable to flee, but hold them back long enough that Wolverine's changes to the timeline erase the Sentinel future from existence.
In 1973, Bolivar Trask pitches the Sentinels to Congress but they decline him so he pitches them to foreign powers. Mystique attempts to kill Trask in revenge for the murders he has committed of mutants while creating the Sentinels, not knowing the future this will create, but is interrupted by Charles Xavier, Beast, Magneto and a time-traveling Wolverine who are attempting to prevent the destruction caused by the Sentinel project's completion. After seeing Xavier's gladness after finding Mystique, Magneto tries to kill Mystique, claiming he is making a more "secure future".
Unfortunately, the fight with Mystique and Magneto exposes mutants to the world and President Nixon agrees to their use while Mystique's blood is collected from where she was wounded, allowing the Sentinels of the future to have her powers. Magneto, both to stop the Sentinels and to use them to take over the world, surrounds them in steel, allowing him to control the Sentinels at their unveiling on the White House lawn. Magneto uses the Sentinels to attack the crowd and hold off Wolverine, Xavier and McCoy, but before he can kill what he believes to be Nixon (really a disguised Mystique), McCoy suppresses his mutation with a serum causing a Sentinel to turn on Magneto.
He quickly disables it, but the distraction allows Mystique to shoot him with a plastic gun, wounding him and then knock him out, deactivating the Sentinels. After Xavier convinces Mystique through telepathy to let Trask, Nixon and his cabinet live, the world sees that a mutant saved the President and the Sentinel program is shut down and Trask is arrested for selling military secrets to foreign powers, erasing the dystopian future.
- Bolivar Trask - Creator
- Mutants - Enemies
- Professor X - attempted victim
- Magneto - attempted victim
- Mystique (revised timeline)
- Beast (revised timeline)
- Shadowcat - attempted victim
- Rogue - attempted victim
- Iceman - victim
- Angel - victim
- Bishop - victim
- Warpath - victim
- Blink - victim
- Sunspot - victim
- Storm - victim
- Wolverine - attempted victim
- Humans - allies