A Jedi Sentinel is the title of one of five distinct schools of thought which a member of the Jedi Order can decide to study under following their ascension to the rank of Jedi Knight, the other four being Guardian, Artisan, Consular, or Seeker. While they possessed considerable combat skills and had somewhat extensive knowledge of the Force, Sentinels blended both schools of teaching and amplified them with a series of non-Force skills, such as in the fields of security, stealth techniques, demolitions, medicine. These skills tended to take the forefront in their middle-road approach to problems; while a Guardian might bash down a locked door and a Consular simply knock, a Sentinel would instead use equipment available or ingenuity to pick the lock. While the role of the Sentinels within the Jedi Order had remained largely consistent throughout its history, the branch of study was first documented by the Sentinel Jedi recruiter Morrit Ch'gally in the text, The Jedi Path: A Manual for Students of the Force.
Within the Jedi Order, the spirit of the Jedi Sentinel had always existed, with many Guardians, Consulars, building a strong connection to the galactic public whom the Order professed to protect. These Jedi were more service-oriented, seeking out cities rather then temples; crowds over solitude. Jedi Knights pursued the Sentinel field of study as a specialization of their specific discipline, in the same way that a Consular might become a healer, or a Guardian might aspire to be a Peacekeeper.
While it was unclear when the Sentinels became their own unique discipline, rather then a specialization within another school of thought, some historians described Master Morrit Ch'gally as the founder of the practical discipline. Ch'gally served as a member of the Army of Light and a Jedi recruiter with the Acquisition Division, and he believed that the differences between his line of though and the Guardians, Consulars, and Seekers, was distinct enough to warrant its own branch of study. Driven by Ch'gally's vision, Sentinels flourished in the post-war era that followed the Ruusan Reformations and spread out into the galaxy, where they became some of the Order's most recognizable members. Many served as freelance law enforcers, and were respected as Jedi that could be approached with any problem.
While studying all of the traditional techniques and abilities that made the Jedi who they were, the Sentinels of the Order found their isolation in the Jedi Temple to be a hindrance if they were expected to be able to work with the civilians of the galaxy. While adherents to the Force and all that it could do, Sentinels were not blinded by faith and realized that the mystical energy field did have its limitations. Typically opting for missions requiring them to stay in a single place for long periods of time, the Sentinels would take on assignments not suited to the other Jedi branches.
The rarely-lit lightsabers of the Sentinels usually produced a yellow blade. Few in numbers, Sentinels had no superior titles such as Sage or Warrior Masters of the other two branches. Instead, they focused on the variety of different techniques needed to be successful as a Sentinel. Known for practicing more specialized Force-techniques, a form of Force Immunity was favored amongst those in this class. Crossing Force-based training with increased mental conditioning, this ability allowed them to better withstand outside mental influences, including Force-based attacks. The most notable Jedi Sentinel serving the Galactic Republic during the Jedi Civil War was Bastila Shan, who, while still a Padawan, mastered the ancient and difficult art of Battle meditation, using it to great effect during the defeat, capture, and redemption of the fallen Jedi Revan.
Sentinels focused on a variety of fields, some with honorifics in the Order, others with skills taken up by professionals in the rest of civilization. Applying their abilities to the art of the slicer, technician, spy, and security experts, the Sentinels also take on very specific titles in the Order
- Law Enforcer: Vital to the training of Jedi Initiates at the Temple, lightsaber instructors were chosen by the current Jedi battlemaster after having served many long years on the front lines of battle. While the title battlemaster was taken up by many Jedi during the New Sith Wars, it was eventually once more used to represent a single Jedi at each academy, recommending potential instructors to the Jedi High Council for appointment.
- Investigator: Organized under the Jedi Starfighter Corps, the Jedi Aces were highly adept pilots and dogfighters. Piloting a variety of different starfighter models over the Order's history, those specializing as Aces used their battle awareness to increase their firing accuracy and precision far beyond what a non-Force-sensitive pilot could achieve. Early on, the Aces served side by side with the Republic Navy, but after its dissolution they worked closely with local defense fleets.
- Shadow: A highly respected and secretive group of Jedi, the Shadows go farther than the Investigators in their hunt for the truth. Working closely with the Council of First Knowledge, the Shadows seek and destroy all traces of the Dark side of the Force, and its adepts. While not always present at the Temple, the Shadows are based in the Temple Precinct and report back as frequently as their mission allows.
- Security: Anonymous sentinels who serve as security force and reported to the Jedi Master who leads the Temple's security detail. They wear formal robes and identity-concealing masks, and are the ultimate expression of emotional detachment required in service to this higher calling. Temple Guards carry imposing lightsaber pikes—thick, double-bladed weapons that produce a rare and distinctive yellow blade. Others are Jedi who choose to work alone in the oversight of peace on a single planet or system. Focusing on bettering society and protecting the rights of a system for years at a time, they are a vital liaison between the planetary government and the Jedi High Council.