StrafeRun-50 Automation cheat for Doom2

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Effect: Causes doom2's StrafeRun-50 (SR-50) mode of straferunning to occur automatically.  Wallrun speeds also appear accellerated beyond that of a normally-executed wallrun. This is not to be confused with "normal" Straferunning, SR-50 is a different type of straferunning that is normally very difficult to activate and control.

Why it is a cheat:  Provides a means for the cheating player to use SR-50 at a level of effectiveness that is not humanly-executable and is fully automated, functioning without any input from the cheating player. The end result is a fully-automated straferun speed that is significantly higher (Turbo 141) than a non-cheating player can achieve .

Method of Implementation: Mouse driver hack

How it works:

    SR-50 itself is not a cheat, it is a normal characteristic of Doom2 movement. It is the automation of SR-50 which is a drastic cheat.

     To understand how SR-50 works, it is necessary to first explain how Strafe-50 and Normal Strafe work (which are seperate but related mechanisms to SR-50). The next few paragraphs explain this difference, which is NOT the SR-50 effect itself:

    Doom2 has two ways in which strafing (stepping directly sideways) can be achieved. One can strafe by (1) defining seperate left and right strafe keys, or (2) using a Strafe-On button that can either be defined on the mouse or the keyboard., and is used in combination with a signal which normally turns the player.

Using these two variations of activating strafing, there are two different kinds of strafing.

"Normal strafing" causes a sideways relative Doom speed of "40" and is achieved by either:
Defining seperate strafe keys, which offers the highest agility for player movement and is the configuration choice of most if not all skilled players, or,

By holding down Strafe-On while activating a key that turns the player.

"Strafe-50" (also known as "faststrafing") is faster than normal strafing, causing a sideways relative Doom speed of "50". It is 25% faster than normal strafing, and is activated in one of two ways:
By activating three key functions at the same time: Strafe-On, one seperately-defined strafe-left or strafe-right key, and a turn left or turn right key. The Strafe-On key can either be defined on the keyboard or on the mouse. Or,

It can be activated by holding down a Strafe-On button (either on the mouse or the keyboard) and moving the mouse to either side at a rate of speed that will generate a full speed strafe.

It's important to note that while the Strafe-On button is activated, both mouse movement from side to side and the normal turn-left and turn-right keys on the keyboard cease to be interpreted as a signal to turn the player, but instead are taken by Doom2 as a strafe command. This inability to immedietely turn artificially limits the reaction time and manuverability of a player (especially a mouse+keys configuration player) who is in Strafe-50 mode.

     The StrafeRun-50 (SR-50) effect is caused as follows:

When strafe-50 is combined with straferunning (a simultaneous forward or backward movement at full speed, which is a doom speed of 50 as well), Doom2 creates the relative forward-angled speed of 50 from these two 50-speeds (one in each direction), and applies the well-known "straferun" diagonal-movement miscalculation to this number. The full speed of the player who is activating SR-50 is relative speed of Turbo 141, and the player is turned at a 45 degree angle.

Note that in order to make this happen without moving the mouse steadily across the mousepad (a problematic thing to maintain simply for a straferun), one has to activate 4 functions at once: Strafe-On, a directional strafe defined with one key, a turn in one direction, and a forward or back.

This contrasts with "normal straferunning", in which Doom takes the simultaneous forward or backward movement from a straferun (a value of 50) and the "normal strafe" speed of 40 and combines them for a relative forward-angled speed of 45. When the known "straferun" miscalculation Doom has is applied to this number, the normal straferunning player comes through at a relative speed of Turbo 128, and the player is turned at a 38 degree angle. All it takes to activate normal straferunning is a forward or backward key operated simultaneously with a directional strafe key.

     Skilled Deathmatchers have historically not used SR-50 as their primary straferunning mechanism because of the intense difficulty in-game caused by (1) the awkwardness of SR-50 activation, and (2) the inability to turn the player, using the mouse or directional keys, while in SR-50 mode. Rememeber, while Strafe-50 (and thus, SR-50) is activated, Doom ceases to accept mouse and keyboard commands for turning, and interprets all turn attempts as strafe commands. To turn, the player must first release the Strafe-On control, and only then will turning of the player be initiated. This requirement makes SR-50 unsuitable most of the time in Deathmatch, which typically requires split second reactions due to unanticipated appearances and movement of the opponent. Releasing the strafe-on button and then turning causes too slow a reaction time to the opponent's movement to be able to risk use of SR-50 frequently. Furthermore, when a player is in SR-50 mode and is running down a corridor, should a small adjustment in the player direction become needed to avoid drifting into the wall or prepare for another manuver, that player cannot precisely correct his course without releasing the Strafe-On button first, once again a slow, unresponsive mechanism for Deathmatch movement. Essentially, the player's ability to mouse aim and adjust is paralyzed while the player is in SR-50 mode, and this limits its prospective uses in Deathmatch.

     And finally: the StrafeRun-50 automation cheat works approximately this way: It involves a hacked mouse driver that attempts to maintain a Strafe-On at all times, except when it detects sideways movement of the mouse. It then ceases to send a Strafe-On signal, allowing the player to turn. When sideways movement of the mouse ceases, it reactivates Strafe-On so that SR-50 is resumed. The player's configuration may need to be adjusted in a way that permits it to work with the mouse driver to create the effect.

The full degree to which SR-50 has been used in the past is still being researched as time permits (read: slowly). This page will be updated as the information is compiled.

If you downloaded the lmpdet utility prior to April 8, 2001, we suggest you download it again to pick up a new version of the documentation textfile within the zip.

You can view the lmpdet.exe documentation textfile here.


Adam Hegyi
StrafeRun-50 detection and analysis tool
U. Girlich
LMP Control panel (LMPC)
John Ripley
Coolmp .lmp statistic generator