diff --git a/src/c_cvars.cpp b/src/c_cvars.cpp
index 72335f1f6..308d53613 100644
--- a/src/c_cvars.cpp
+++ b/src/c_cvars.cpp
@@ -132,10 +132,10 @@ FBaseCVar::~FBaseCVar ()
 	}
 }
 
-void FBaseCVar::ForceSet (UCVarValue value, ECVarType type)
+void FBaseCVar::ForceSet (UCVarValue value, ECVarType type, bool nouserinfosend)
 {
 	DoSet (value, type);
-	if ((Flags & CVAR_USERINFO) && !(Flags & CVAR_IGNORE))
+	if ((Flags & CVAR_USERINFO) && !nouserinfosend && !(Flags & CVAR_IGNORE))
 		D_UserInfoChanged (this);
 	if (m_UseCallback)
 		Callback ();
diff --git a/src/c_cvars.h b/src/c_cvars.h
index e6b7388c2..f1bf254b9 100644
--- a/src/c_cvars.h
+++ b/src/c_cvars.h
@@ -101,7 +101,7 @@ public:
 	inline FBaseCVar *GetNext() const { return m_Next; }
 
 	void CmdSet (const char *newval);
-	void ForceSet (UCVarValue value, ECVarType type);
+	void ForceSet (UCVarValue value, ECVarType type, bool nouserinfosend=false);
 	void SetGenericRep (UCVarValue value, ECVarType type);
 	void ResetToDefault ();
 	void SetArchiveBit () { Flags |= CVAR_ARCHIVE; }
diff --git a/src/d_netinfo.cpp b/src/d_netinfo.cpp
index 6b89efc22..7f94ef686 100644
--- a/src/d_netinfo.cpp
+++ b/src/d_netinfo.cpp
@@ -430,7 +430,7 @@ void userinfo_t::Reset()
 			case NAME_PlayerClass:	type = CVAR_Int; break;
 			default:				type = cvar->GetRealType(); break;
 			}
-			newcvar = C_CreateCVar(NULL, type, 0);
+			newcvar = C_CreateCVar(NULL, type, cvar->GetFlags() & CVAR_MOD);
 			newcvar->SetGenericRepDefault(cvar->GetGenericRepDefault(CVAR_String), CVAR_String);
 			Insert(cvarname, newcvar);
 		}
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 42e2cfec8..f251ab2e7 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -3474,6 +3474,9 @@ enum EACSFunctions
 	ACSF_VectorLength,
 	ACSF_SetHUDClipRect,
 	ACSF_SetHUDWrapWidth,
+	ACSF_SetCVar,
+	ACSF_GetUserCVar,
+	ACSF_SetUserCVar,
 
 	// ZDaemon
 	ACSF_GetTeamScore = 19620,	// (int team)
@@ -3573,6 +3576,145 @@ static int GetUserVariable(AActor *self, FName varname, int index)
 	return 0;
 }
 
+// Converts fixed- to floating-point as required.
+static void DoSetCVar(FBaseCVar *cvar, int value, bool force=false)
+{
+	UCVarValue val;
+	ECVarType type;
+
+	// For serverinfo variables, only the arbitrator should set it.
+	// The actual change to this cvar will not show up until it's
+	// been replicated to all peers.
+	if ((cvar->GetFlags() & CVAR_SERVERINFO) && consoleplayer != Net_Arbitrator)
+	{
+		return;
+	}
+	if (cvar->GetRealType() == CVAR_Float)
+	{
+		val.Float = FIXED2FLOAT(value);
+		type = CVAR_Float;
+	}
+	else
+	{
+		val.Int = value;
+		type = CVAR_Int;
+	}
+	if (force)
+	{
+		cvar->ForceSet(val, type, true);
+	}
+	else
+	{
+		cvar->SetGenericRep(val, type);
+	}
+}
+
+// Converts floating- to fixed-point as required.
+static int DoGetCVar(FBaseCVar *cvar)
+{
+	UCVarValue val;
+
+	if (cvar->GetRealType() == CVAR_Float)
+	{
+		val = cvar->GetGenericRep(CVAR_Float);
+		return FLOAT2FIXED(val.Float);
+	}
+	else
+	{
+		val = cvar->GetGenericRep(CVAR_Int);
+		return val.Int;
+	}
+}
+
+static int GetUserCVar(int playernum, const char *cvarname)
+{
+	if ((unsigned)playernum >= MAXPLAYERS || !playeringame[playernum])
+	{
+		return 0;
+	}
+	FBaseCVar **cvar_p = players[playernum].userinfo.CheckKey(FName(cvarname, true));
+	FBaseCVar *cvar;
+	if (cvar_p == NULL || (cvar = *cvar_p) == NULL || (cvar->GetFlags() & CVAR_IGNORE))
+	{
+		return 0;
+	}
+	return DoGetCVar(cvar);
+}
+
+static int GetCVar(AActor *activator, const char *cvarname)
+{
+	FBaseCVar *cvar = FindCVar(cvarname, NULL);
+	// Either the cvar doesn't exist, or it's for a mod that isn't loaded, so return 0.
+	if (cvar == NULL || (cvar->GetFlags() & CVAR_IGNORE))
+	{
+		return 0;
+	}
+	else
+	{
+		// For userinfo cvars, redirect to GetUserCVar
+		if (cvar->GetFlags() & CVAR_USERINFO)
+		{
+			if (activator == NULL || activator->player == NULL)
+			{
+				return 0;
+			}
+			return GetUserCVar(int(activator->player - players), cvarname);
+		}
+		return DoGetCVar(cvar);
+	}
+}
+
+static int SetUserCVar(int playernum, const char *cvarname, int value)
+{
+	if ((unsigned)playernum >= MAXPLAYERS || !playeringame[playernum])
+	{
+		return 0;
+	}
+	FBaseCVar **cvar_p = players[playernum].userinfo.CheckKey(FName(cvarname, true));
+	FBaseCVar *cvar;
+	// Only mod-created cvars may be set.
+	if (cvar_p == NULL || (cvar = *cvar_p) == NULL || (cvar->GetFlags() & CVAR_IGNORE) || !(cvar->GetFlags() & CVAR_MOD))
+	{
+		return 0;
+	}
+	DoSetCVar(cvar, value);
+
+	// If we are this player, then also reflect this change in the local version of this cvar.
+	if (playernum == consoleplayer)
+	{
+		FBaseCVar *cvar = FindCVar(cvarname, NULL);
+		// If we can find it in the userinfo, then we should also be able to find it in the normal cvar list,
+		// but check just to be safe.
+		if (cvar != NULL)
+		{
+			DoSetCVar(cvar, value, true);
+		}
+	}
+
+	return 1;
+}
+
+static int SetCVar(AActor *activator, const char *cvarname, int value)
+{
+	FBaseCVar *cvar = FindCVar(cvarname, NULL);
+	// Only mod-created cvars may be set.
+	if (cvar == NULL || (cvar->GetFlags() & (CVAR_IGNORE|CVAR_NOSET)) || !(cvar->GetFlags() & CVAR_MOD))
+	{
+		return 0;
+	}
+	// For userinfo cvars, redirect to SetUserCVar
+	if (cvar->GetFlags() & CVAR_USERINFO)
+	{
+		if (activator == NULL || activator->player == NULL)
+		{
+			return 0;
+		}
+		return SetUserCVar(int(activator->player - players), cvarname, value);
+	}
+	DoSetCVar(cvar, value);
+	return 1;
+}
+
 int DLevelScript::CallFunction(int argCount, int funcIndex, SDWORD *args)
 {
 	AActor *actor;
@@ -4017,6 +4159,27 @@ int DLevelScript::CallFunction(int argCount, int funcIndex, SDWORD *args)
 			WrapWidth = argCount > 0 ? args[0] : 0;
 			break;
 
+		case ACSF_GetUserCVar:
+			if (argCount == 2)
+			{
+				return GetUserCVar(args[0], FBehavior::StaticLookupString(args[1]));
+			}
+			break;
+
+		case ACSF_SetUserCVar:
+			if (argCount == 3)
+			{
+				return SetUserCVar(args[0], FBehavior::StaticLookupString(args[1]), args[2]);
+			}
+			break;
+
+		case ACSF_SetCVar:
+			if (argCount == 2)
+			{
+				return SetCVar(activator, FBehavior::StaticLookupString(args[0]), args[1]);
+			}
+			break;
+
 		default:
 			break;
 	}
@@ -6883,19 +7046,7 @@ scriptwait:
 			break;
 
 		case PCD_GETCVAR:
-			{
-				FBaseCVar *cvar = FindCVar (FBehavior::StaticLookupString (STACK(1)), NULL);
-				// Either the cvar doesn't exist, or it's for a mod that isn't loaded, so return 0.
-				if (cvar == NULL || (cvar->GetFlags() & CVAR_IGNORE))
-				{
-					STACK(1) = 0;
-				}
-				else
-				{
-					UCVarValue val = cvar->GetGenericRep (CVAR_Int);
-					STACK(1) = val.Int;
-				}
-			}
+			STACK(1) = GetCVar(activator, FBehavior::StaticLookupString(STACK(1)));
 			break;
 
 		case PCD_SETHUDSIZE: