關於the location in Fallout 4,參見Institute Synth Retention

My God, I... I remember. I remember it all. From before. Zimmer. The Commonwealth. The Institute. My God, all those runners I brought down...Harkness, after his memory is restored

The Synth Retention Bureau or S.R.B. is a branch of the Institute tasked with capturing escaped androids (or "synths").


After the Institute began creating advanced synthetic humans ("synths") around 2227, many developed strong personalities and a desire to escape their life of servitude. Despite their apparent ability to feel and think freely, synths are treated as slaves in the Institute, only utilized for maintenance and security purposes. With the help of Institute synth sympathizers like Liam Binet, and factions like the Railroad, many synths have escaped the Institute, most of them subsequently having their minds wiped and faces reconstructed, allowing them to live lives as normal humans.

As a result of the synth escapes, the Institute founded the Synth Retention Bureau, or S.R.B., a branch of the Institute dedicated solely to the recovery and rehabilitation of escaped synths. The Institute scientists developed advanced synths with incredible combat capabilities and dulled personalities known as coursers, designed to track down and reclaim escaped synths at all costs. Due to the effectiveness and brutality of the coursers' methods, the S.R.B. is feared by all escaped synths, and even by some of the synths and scientists within the Institute itself. Inside the Institute the Sole Survivor learns of the tension between the S.R.B and the other divisions (especially Advanced Systems) and that a scientist named William Moseley was employed as a bridge between the two divisions.

Known members


Former members

  • Harkness (originally designated A3-21)
  • Chase (former courser)



  • S3-47 (Armitage)
  • X4-18
  • X6-88
  • X9-27
  • Z2-47
  • B8-88
  • C8-65
  • F5-93
  • G6-43
  • H7-44
  • J1-74
  • J8-28
  • K0-84
  • K2-90
  • K6-70
  • L7-92
  • M9-11
  • P1-77
  • Q2-87
  • R6-01
  • R7-81
  • T3-54
  • W4-40
  • X1-02
  • X1-91
  • X2-36
  • X2-71
  • X3-24
  • X3-28
  • X3-37
  • X3-51
  • X5-76
  • X6-57
  • X7-55
  • X9-73



The Synth Retention Bureau is mentioned in Fallout 3 and appears in Fallout 4.