This article is about the version of Death Run used specifically by SCG; to learn about more about the mode itself, refer to the Team Fortress 2 Wiki article on it.
Death Run, or Obstacle Course, is a custom TF2 Game Mode where players must complete a run through an obstacle course type map, typically filled with traps that are activated by the "Death" player. The goal is to complete the course alive, where as the goal for the Death player is to kill all other players. Typically when players complete the map successfully, there are open an assortment of options to pick from as to how the Death player should meet their end.
!drtoggle to toggle whether or not you can become death. If there aren't enough players, this feature is disabled until more arrive.
The term "Death Run" came from Icepick66 via their map of the same name made for Counter Strike: Source. However, the inspiration came from the Team Fortress Classic map, Heavy Machinery by PhillthyBoyee.