The SR-50, also known as the StrafeRun-50 or simply the Strafe 50, is a speedrunning technique used in Duke Nukem 3D. In combination with the Steroids, it allows for the fastest method of movement in the game.
To perform the SR-50, Auto-Run must first be turned "On." Then, four movement keys must be held simultaneously:
- Forwards OR Backwards
- Strafe Left OR Strafe Right
- Turn Left OR Turn Right
If Strafe Left is being held, then it must be paired with Turn Left, and if Strafe Right is being held, then it must be paired with Turn Right.
Using the default key bindings, the Caps Lock button can toggle Auto-Run "On" and "Off." With Auto-Run turned "On," the following four keys can be used to perform the SR-50 when held simultaneously:
- W (Forwards)
- D (Strafe Right)
- Right Alt (Strafe)
- Right Arrow (Turn Right)
Comparison with Other Movement Techniques
The SR-50 involves more than basic strafe-running. With Auto-Run turned "On," strafe-running can be performed by holding the Forwards key and either the Strafe Left or Strafe Right key. Strafe-running is noticeably much faster than normal running, but it is not as fast as the SR-50.
The speedrunner O_Circles has found that the following speed unit values correspond with each of the standard methods of movement:
- Normal Running: 174
- Strafe-Running: 244
- SR-50: 259
Because it is barely faster than normal strafe-running, it may be difficult to perceive the increase in movement when switching from strafe-running to the SR-50. However, the difference is amplified when using Steroids. O_Circles identified the following speed unit values with Steroids:
- Steroids + Strafe-Running: 488
- Steroids + SR-50: 520
The SR-50 was first discovered by the Doom speedrunning community. The "StrafeRun-50" gets its name from the fact that, in Doom, the technique allows for 50 units of movement at a time. Although the SR-50 does not result in 50 units of movement in Duke Nukem, the technique was already well-known, so Duke Nukem speedrunners kept the name. Fernando "Fernito" Márquez was the first Duke Nukem speedrunner to apply the technique on the Duke Nukem speedrunning leaderboards, circa 2007.
- Speedrunning in Duke Nukem 3D
- O_Circles: Things I wish I knew from the start (Speedrun.com Guide)
- Alex "pogokeen" Dawson: Glitches in Duke Nukem 3D (Red-Stars.net)
- Fernando Calvo's speedruns, demonstrating the SR-50 (YouTube Playlist)