|Out of universe information|
|Actor||Dean Redman (Light Jet Sentry)
Rob Daly (Lead Sentry)
A Sentry is a modified system monitor security program tasked with maintaining order on the Grid. Sentries wear standard black garb with red circuitry, and have black visored helmets with an open lower face below the visor. They possess identity discs, but most prefer to fight with their staffs.
There are two Sentry variants that appear in TRON: Evolution, along with the regular Sentries. One is the Heavy Sentry, a slow moving sentry that wears thick armor and carries a large shield. Heavies can preform devastating attacks by slamming their shields into the ground. The other is the Scout Sentry, wearing lighter armor and with a sail-like attachment on their backs. Scouts are quick, and attack by using a hit-and-run strategy.
Sentries commonly use recognizers for transportation and surveillance.
Sentries, originally known as System Monitors, were loyal to the system and could be found guarding key points around the Grid's cities. Several were guarding the entrance to the Co-Admin Installation Ceremony when the virus Abraxas arrived. Clu ordered three sentries to arrest him but they were derezzed by the virus. To stop the virus from advancing further, Clu ordered a lone remaining sentry to sever the stage bridge, but he too was derezzed. Clu was saved by the timely arrival of Anon.
Clu's sentries continued to battle programs infected by Abraxas, never knowing that the virus had been engineered by Clu himself. When Clu spread a false report that Anon had been infected, the Grid's sentries were tasked with taking him down too, but did not succeed.
After the coup, sentries retained a significant place in Clu's security forces, carrying out maneuvers and guarding high-priority access areas as far away as Argon City.
By TRON: Legacy, sentries were regularly kidnapping programs off the streets, with each team's leader assigning the captives to either rectification or the Games. Those set aside for rectification were repurposed into new sentries, while the rest would face the Arena and certain deresolution; it fell to the sentries to escort each group to its destination. Repurposed sentries formed the backbone of the army with which Clu was preparing to invade the real world.
A quartet of sentries joined Clu to form a five-program team of light cycle riders pitted against Sam Flynn's team on the Light Cycle Grid. These sentries wore a different style of helmet than the common foot patrol sentries, very similar to the helmets of the opposing team, although the sentries had darkened visors. These sentries gained the initial advantage, but were ultimately all derezzed when Sam rallied what remained of his team.
Sam later borrowed his father's light cycle to get to Zuse's sector in Tron City, passing a sentry stationed in a guard tower near the bridge leading into the city and two others who were busy arresting a program. Sam exchanged the light cycle for the cloak of a destitute program he found in an alley; the two remaining sentries on the street, unaware that the light cycle now had a different rider, pursued and eventually captured it. Two more sentries were seen talking with programs at the elevator to the End of Line Club when Gem and Sam approached its tower, and others were found relaxing in the club, too distracted by drinks and feminine company to notice the user's entrance.
A lone sentry provided a brief insight into the base nature of this type of program when Kevin Flynn stole up behind him, intending to hijacking one of the light jets he was guarding. Flynn accessed the identity disc on the sentry's back, effectively patching his code. When the sentry turned around, he was initially obstinate and insisted that Flynn was not authorized to access the light jet. Flynn responded by thumping the program on the helmet, forcing the patch to take effect. The sentry then allowed him to pass, and advised him to watch his step as he boarded the vehicle.
When Flynn reintegrated with Clu, the resulting explosion enveloped Clu's approaching ship and destroyed it, derezzing Clu's army of repurposed sentries.