Courser

Coursers are elite synth hunters and operatives designated to carry out specific surface missions from the Institute. They operate around the Commonwealth in 2287.

Background
The primary instrument of the SRB is the Courser, a third-generation synth assigned to operate on the surface. Coursers hunt down and reclaim synths that have escaped the Institute. They are highly self-sufficient, trained in combat, infiltration, and tracking. In a word, Coursers are relentless.

The Coursers are designed to be elite killing machines, unlike other synth models. Under the orders of the SRB, the department assigns Coursers their missions and provide access to the surface via relay from their courser chip, a form of teleportation. The SRB primarily uses Coursers to retrieve and reset escaped synths. Once an escaped synth is found, a Courser uses the synth's recall code to wipe its memories and render it inert. Once done, the synth is brought back to the Institute to have its neural pathways restored and regulated back to its original functions, wiping its memories of its time on the surface, although numerous cases involve irreparable damage and the disposal of many escaped synths.

Coursers are drawn from the third generation synth population, constantly monitored for tenacity, fearlessness, and independence. When synths are identified with these traits, the basic necessary skills are transferred into their minds. Stealth, espionage, combat training as well as survival and repair skills. They then undergo a rigorous training regimen. Where they further hone these new abilities to even higher levels. Everything from armed and unarmed combat, investigative techniques, psychology, and even mechanical skills must be perfected. Those who pass a final evaluation become Coursers, re-registered as X (eg. X6-88) or Z (eg. Z2-47) synths, and receive final upgrades: Subdermal armor implants increasing their resilience in combat, roughly equivalent to a full suit of combat armor, and their cranial synth implant is upgraded with a Courser chip to relay them into and out of the Institute. However, those who fail the evaluation have their memories wiped and return to their former duties.

They are noted by the Railroad and the Institute to be exceptional even for synths, as they possess exceptional strength, combat prowess, awareness, and endurance. They are widely feared by the Railroad, as their first instinct when they see a Courser is to cease all operations and remain low.

Notable coursers

 * Chase - She worked for the Institute until she met DiMA and was convinced of his mission. She is the only known female Courser and the only known Courser to have voluntarily left the Institute.
 * X4-18 - During the quest The Battle of Bunker Hill he is found waiting for the arrival of the Sole Survivor.
 * X6-88 - He is a possible companion who is assigned to the Sole Survivor in Synth Retention. He is available as a companion after Mankind - Redefined. He also appears in Kellogg's memories.
 * X9-27 - He will be met during the quest Operation Ticonderoga hunting for the Railroad agents as ordered by the Institute.
 * Z2-47 - He is encountered in Greenetech Genetics during the Hunter/Hunted quest while killing the resident Gunners on his mission to recover a runaway synth. He is the first courser to physically appear in the game.
 * B-263 - A dead courser found during the Creation Club content "Noir Penthouse."
 * Reinhart VII, a courser cut from Far Harbor.

Appearances
Coursers appear only in Fallout 4.

Behind the scenes
The term "courser" was not used until the Institute was fleshed out in Fallout 4, although Harkness (A3-21) from Fallout 3 performed a role similar to a courser.