diff --git a/Quake/host.c b/Quake/host.c
index e3e04755..71b1bfd6 100644
--- a/Quake/host.c
+++ b/Quake/host.c
@@ -63,6 +63,9 @@ float  host_netinterval = 1.0 / 72;
 cvar_t host_framerate = {"host_framerate", "0", CVAR_NONE}; // set for slow motion
 cvar_t host_speeds = {"host_speeds", "0", CVAR_NONE};		// set for running times
 cvar_t host_maxfps = {"host_maxfps", "200", CVAR_ARCHIVE};	// johnfitz
+
+cvar_t host_phys_cst_ticrate = {"host_phys_cst_ticrate", "0", CVAR_ARCHIVE}; // vso = [0 = disabled; 72]
+
 cvar_t host_timescale = {"host_timescale", "0", CVAR_NONE}; // johnfitz
 cvar_t max_edicts = {"max_edicts", "8192", CVAR_NONE};		// johnfitz //ericw -- changed from 2048 to 8192, removed CVAR_ARCHIVE
 cvar_t cl_nocsqc = {"cl_nocsqc", "0", CVAR_NONE};			// spike -- blocks the loading of any csqc modules
@@ -110,6 +113,10 @@ static void Max_Edicts_f (cvar_t *var)
 		Con_Printf ("Changes to max_edicts will not take effect until the next time a map is loaded.\n");
 }
 
+// forward declarations for below...
+static void Max_Fps_f (cvar_t *var);
+static void Phys_Ticrate_f (cvar_t *var);
+
 /*
 ================
 Max_Fps_f -- ericw
@@ -117,6 +124,13 @@ Max_Fps_f -- ericw
 */
 static void Max_Fps_f (cvar_t *var)
 {
+	// host_phys_cst_ticrate overrides normal behaviour
+	if (host_phys_cst_ticrate.value > 0)
+	{
+		Phys_Ticrate_f (&host_phys_cst_ticrate);
+		return;
+	}
+
 	if (var->value > 72 || var->value <= 0)
 	{
 		if (!host_netinterval)
@@ -134,6 +148,27 @@ static void Max_Fps_f (cvar_t *var)
 	}
 }
 
+/*
+================
+Phys_Ticrate_f -- vso
+================
+*/
+static void Phys_Ticrate_f (cvar_t *var)
+{
+	if (var->value > 0)
+	{
+		// clamp within valid limits, use only integer values
+		var->value = roundf (CLAMP (0, var->value, 72));
+
+		Con_Printf ("Using constant physics tics rate = %dHz.\n", (int)var->value);
+		host_netinterval = 1.0 / var->value;
+	}
+	else
+	{ // apply max_fps policy
+		Max_Fps_f (&host_maxfps);
+	}
+}
+
 /*
 ================
 Host_EndGame
@@ -296,6 +331,9 @@ void Host_InitLocal (void)
 	Cvar_SetCallback (&host_maxfps, Max_Fps_f);
 	Cvar_RegisterVariable (&host_timescale); // johnfitz
 
+	Cvar_RegisterVariable (&host_phys_cst_ticrate);			   // vso
+	Cvar_SetCallback (&host_phys_cst_ticrate, Phys_Ticrate_f); // vso
+
 	Cvar_RegisterVariable (&cl_nocsqc);	 // spike
 	Cvar_RegisterVariable (&max_edicts); // johnfitz
 	Cvar_SetCallback (&max_edicts, Max_Edicts_f);