diff --git a/extras/conf/Includes/SRB222_linedefs.cfg b/extras/conf/Includes/SRB222_linedefs.cfg
index fdf191850..9f6613620 100644
--- a/extras/conf/Includes/SRB222_linedefs.cfg
+++ b/extras/conf/Includes/SRB222_linedefs.cfg
@@ -2483,4 +2483,119 @@ udmf
 			prefix = "(0)";
 		}
 	}
+
+	slope
+	{
+		title = "Slope";
+
+		700
+		{
+			title = "Create Sector-Based Slope";
+			prefix = "(700)";
+			id = "plane_align";
+			slope = "regular";
+			arg0
+			{
+				title = "Floor";
+				type = 11;
+				enum = "frontback";
+			}
+			arg1
+			{
+				title = "Ceiling";
+				type = 11;
+				enum = "frontback";
+			}
+			arg2
+			{
+				title = "Flags";
+				type = 12;
+				enum
+				{
+					1 = "No physics";
+					2 = "Dynamic";
+				}
+			}
+		}
+
+		704
+		{
+			title = "Create Vertex-Based Slope";
+			prefix = "(704)";
+			slope = "vertex";
+			arg0
+			{
+				title = "Plane";
+				type = 11;
+				enum
+				{
+					0 = "Front floor";
+					1 = "Front ceiling";
+					2 = "Back floor";
+					3 = "Back ceiling";
+				}
+			}
+			arg1
+			{
+				title = "Vertex 1 tag";
+			}
+			arg2
+			{
+				title = "Vertex 2 tag";
+			}
+			arg3
+			{
+				title = "Vertex 3 tag";
+			}
+			arg4
+			{
+				title = "Flags";
+				type = 12;
+				enum
+				{
+					1 = "No physics";
+					2 = "Dynamic";
+				}
+			}
+		}
+
+		720
+		{
+			title = "Copy Slope";
+			prefix = "(720)";
+			slope = "copy";
+			arg0
+			{
+				title = "Front floor tag";
+				type = 13;
+			}
+			arg1
+			{
+				title = "Front ceiling tag";
+				type = 13;
+			}
+			arg2
+			{
+				title = "Back floor tag";
+				type = 13;
+			}
+			arg3
+			{
+				title = "Back ceiling tag";
+				type = 13;
+			}
+			arg4
+			{
+				title = "Share slope";
+				type = 12;
+				enum
+				{
+					1 = "Front floor to back sector";
+					2 = "Back floor to front sector";
+					4 = "Front ceiling to back sector";
+					8 = "Back ceiling to front sector";
+				}
+			}
+		}
+	}
 }
\ No newline at end of file
diff --git a/extras/conf/Includes/SRB222_misc.cfg b/extras/conf/Includes/SRB222_misc.cfg
index ce23388b2..7fe4890fd 100644
--- a/extras/conf/Includes/SRB222_misc.cfg
+++ b/extras/conf/Includes/SRB222_misc.cfg
@@ -63,19 +63,19 @@ linedefflags_udmf
 	midpeg = "Peg Midtexture";
 	midsolid = "Solid Midtexture";
 	wrapmidtex = "Repeat Midtexture";
-//	netonly = "Netgame-Only special";
-//	nonet = "No netgame special";
-//	effect6 = "Effect 6";
+//	netonly = "Netgame Only";
+//	nonet = "No Netgame";
+	effect6 = "Effect 6";
 	bouncy = "Bouncy Wall";
-//	transfer = "Transfer Line";
+	transfer = "Transfer Line";
 }
 
 
 linedefactivations_udmf
 {
-	notriggerorder = "Out of Order";
-	netonly = "Netgame-Only";
-	nonet = "No netgame";
+//	notriggerorder = "Out of Order";
+	netonly = "Netgame Only";
+	nonet = "No Netgame";
 }
 
 sidedefflags
diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index 2a82ec512..8c4739b02 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -175,6 +175,7 @@ static const struct {
 
 	{META_SECTORLINES,  "sector_t.lines"},
 	{META_SIDENUM,      "line_t.sidenum"},
+	{META_LINEARGS,     "line_t.args"},
 #ifdef HAVE_LUA_SEGS
 	{META_NODEBBOX,     "node_t.bbox"},
 	{META_NODECHILDREN, "node_t.children"},
diff --git a/src/lua_libs.h b/src/lua_libs.h
index 6a908d03d..155c34eaa 100644
--- a/src/lua_libs.h
+++ b/src/lua_libs.h
@@ -56,6 +56,7 @@ extern lua_State *gL;
 
 #define META_SECTORLINES "SECTOR_T*LINES"
 #define META_SIDENUM "LINE_T*SIDENUM"
+#define META_LINEARGS "LINE_T*ARGS"
 #ifdef HAVE_LUA_SEGS
 #define META_NODEBBOX "NODE_T*BBOX"
 #define META_NODECHILDREN "NODE_T*CHILDREN"
diff --git a/src/lua_maplib.c b/src/lua_maplib.c
index 309ba86a1..03da0a2e0 100644
--- a/src/lua_maplib.c
+++ b/src/lua_maplib.c
@@ -94,6 +94,7 @@ enum line_e {
 	line_flags,
 	line_special,
 	line_tag,
+	line_args,
 	line_sidenum,
 	line_frontside,
 	line_backside,
@@ -115,6 +116,7 @@ static const char *const line_opt[] = {
 	"flags",
 	"special",
 	"tag",
+	"args",
 	"sidenum",
 	"frontside",
 	"backside",
@@ -701,6 +703,24 @@ static int subsector_num(lua_State *L)
 // line_t //
 ////////////
 
+// args, i -> args[i]
+static int lineargs_get(lua_State *L)
+{
+	INT32 *args = *((INT32**)luaL_checkudata(L, 1, META_LINEARGS));
+	int i = luaL_checkinteger(L, 2);
+	if (i < 0 || i >= NUMLINEARGS)
+		return luaL_error(L, LUA_QL("line_t.args") " index cannot be %d", i);
+	lua_pushinteger(L, args[i]);
+	return 1;
+}
+
+// #args -> NUMLINEARGS
+static int lineargs_len(lua_State* L)
+{
+	lua_pushinteger(L, NUMLINEARGS);
+	return 1;
+}
+
 static int line_get(lua_State *L)
 {
 	line_t *line = *((line_t **)luaL_checkudata(L, 1, META_LINE));
@@ -741,6 +761,9 @@ static int line_get(lua_State *L)
 	case line_tag:
 		lua_pushinteger(L, line->tag);
 		return 1;
+	case line_args:
+		LUA_PushUserdata(L, line->args, META_LINEARGS);
+		return 1;
 	case line_sidenum:
 		LUA_PushUserdata(L, line->sidenum, META_SIDENUM);
 		return 1;
@@ -2137,6 +2160,14 @@ int LUA_MapLib(lua_State *L)
 		lua_setfield(L, -2, "__len");
 	lua_pop(L, 1);
 
+	luaL_newmetatable(L, META_LINEARGS);
+		lua_pushcfunction(L, lineargs_get);
+		lua_setfield(L, -2, "__index");
+
+		lua_pushcfunction(L, lineargs_len);
+		lua_setfield(L, -2, "__len");
+	lua_pop(L, 1);
+
 	luaL_newmetatable(L, META_SIDENUM);
 		lua_pushcfunction(L, sidenum_get);
 		lua_setfield(L, -2, "__index");
diff --git a/src/p_saveg.c b/src/p_saveg.c
index 2b6a474bf..1e6451164 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -768,6 +768,17 @@ static void P_NetUnArchiveColormaps(void)
 #define LD_S2TOPTEX 0x02
 #define LD_S2BOTTEX 0x04
 #define LD_S2MIDTEX 0x08
+#define LD_ARGS     0x10
+
+static boolean P_AreArgsEqual(const INT32 args[NUMLINEARGS], const INT32 spawnargs[NUMLINEARGS])
+{
+	UINT8 i;
+	for (i = 0; i < NUMLINEARGS; i++)
+		if (args[i] != spawnargs[i])
+			return false;
+
+	return true;
+}
 
 //
 // P_NetArchiveWorld
@@ -944,6 +955,9 @@ static void P_NetArchiveWorld(void)
 		if (spawnli->special == 321 || spawnli->special == 322) // only reason li->callcount would be non-zero is if either of these are involved
 			diff |= LD_CLLCOUNT;
 
+		if (!P_AreArgsEqual(li->args, spawnli->args))
+			diff2 |= LD_ARGS;
+
 		if (li->sidenum[0] != 0xffff)
 		{
 			si = &sides[li->sidenum[0]];
@@ -970,10 +984,11 @@ static void P_NetArchiveWorld(void)
 				diff2 |= LD_S2BOTTEX;
 			if (si->midtexture != spawnsi->midtexture)
 				diff2 |= LD_S2MIDTEX;
-			if (diff2)
-				diff |= LD_DIFF2;
 		}
 
+		if (diff2)
+			diff |= LD_DIFF2;
+
 		if (diff)
 		{
 			statline++;
@@ -1007,6 +1022,12 @@ static void P_NetArchiveWorld(void)
 				WRITEINT32(put, si->bottomtexture);
 			if (diff2 & LD_S2MIDTEX)
 				WRITEINT32(put, si->midtexture);
+			if (diff2 & LD_ARGS)
+			{
+				UINT8 j;
+				for (j = 0; j < NUMLINEARGS; j++)
+					WRITEINT32(put, li->args[j]);
+			}
 		}
 	}
 	WRITEUINT16(put, 0xffff);
@@ -1190,6 +1211,13 @@ static void P_NetUnArchiveWorld(void)
 			si->bottomtexture = READINT32(get);
 		if (diff2 & LD_S2MIDTEX)
 			si->midtexture = READINT32(get);
+		if (diff2 & LD_ARGS)
+		{
+			UINT8 j;
+			for (j = 0; j < NUMLINEARGS; j++)
+				li->args[j] = READINT32(get);
+		}
+
 	}
 
 	save_p = get;
diff --git a/src/p_setup.c b/src/p_setup.c
index cfe141381..dc7f07d9e 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -1052,6 +1052,7 @@ static void P_LoadLinedefs(UINT8 *data)
 		ld->flags = SHORT(mld->flags);
 		ld->special = SHORT(mld->special);
 		ld->tag = SHORT(mld->tag);
+		memset(ld->args, 0, NUMLINEARGS*sizeof(*ld->args));
 		P_SetLinedefV1(i, SHORT(mld->v1));
 		P_SetLinedefV2(i, SHORT(mld->v2));
 
@@ -1426,6 +1427,13 @@ static void ParseTextmapLinedefParameter(UINT32 i, char *param, char *val)
 		P_SetLinedefV1(i, atol(val));
 	else if (fastcmp(param, "v2"))
 		P_SetLinedefV2(i, atol(val));
+	else if (fastncmp(param, "arg", 3) && strlen(param) > 3)
+	{
+		size_t argnum = atol(param + 3);
+		if (argnum >= NUMLINEARGS)
+			return;
+		lines[i].args[argnum] = atol(val);
+	}
 	else if (fastcmp(param, "sidefront"))
 		lines[i].sidenum[0] = atol(val);
 	else if (fastcmp(param, "sideback"))
@@ -1613,6 +1621,7 @@ static void P_LoadTextmap(void)
 		ld->flags = 0;
 		ld->special = 0;
 		ld->tag = 0;
+		memset(ld->args, 0, NUMLINEARGS*sizeof(*ld->args));
 		ld->sidenum[0] = 0xffff;
 		ld->sidenum[1] = 0xffff;
 
@@ -2634,6 +2643,97 @@ static void P_LinkMapData(void)
 	}
 }
 
+//For maps in binary format, converts setup of specials to UDMF format.
+static void P_ConvertBinaryMap(void)
+{
+	size_t i;
+
+	for (i = 0; i < numlines; i++)
+	{
+		switch (lines[i].special)
+		{
+		case 700: //Slope front sector floor
+		case 701: //Slope front sector ceiling
+		case 702: //Slope front sector floor and ceiling
+		case 703: //Slope front sector floor and back sector ceiling
+		case 710: //Slope back sector floor
+		case 711: //Slope back sector ceiling
+		case 712: //Slope back sector floor and ceiling
+		case 713: //Slope back sector floor and front sector ceiling
+		{
+			boolean frontfloor = (lines[i].special == 700 || lines[i].special == 702 || lines[i].special == 703);
+			boolean backfloor = (lines[i].special == 710 || lines[i].special == 712 || lines[i].special == 713);
+			boolean frontceil = (lines[i].special == 701 || lines[i].special == 702 || lines[i].special == 713);
+			boolean backceil = (lines[i].special == 711 || lines[i].special == 712 || lines[i].special == 703);
+
+			lines[i].args[0] = backfloor ? 2 : (frontfloor ? 1 : 0);
+			lines[i].args[1] = backceil ? 2 : (frontceil ? 1 : 0);
+
+			if (lines[i].flags & ML_NETONLY)
+				lines[i].args[2] |= SL_NOPHYSICS;
+			if (lines[i].flags & ML_NONET)
+				lines[i].args[2] |= SL_DYNAMIC;
+
+			lines[i].special = 700;
+			break;
+		}
+		case 704: //Slope front sector floor by 3 tagged vertices
+		case 705: //Slope front sector ceiling by 3 tagged vertices
+		case 714: //Slope back sector floor by 3 tagged vertices
+		case 715: //Slope back sector ceiling  by 3 tagged vertices
+		{
+			if (lines[i].special == 704)
+				lines[i].args[0] = 0;
+			else if (lines[i].special == 705)
+				lines[i].args[0] = 1;
+			else if (lines[i].special == 714)
+				lines[i].args[0] = 2;
+			else if (lines[i].special == 715)
+				lines[i].args[0] = 3;
+
+			lines[i].args[1] = lines[i].tag;
+
+			if (lines[i].flags & ML_EFFECT6)
+			{
+				UINT8 side = lines[i].special >= 714;
+
+				if (side == 1 && lines[i].sidenum[1] == 0xffff)
+					CONS_Debug(DBG_GAMELOGIC, "P_ConvertBinaryMap: Line special %d (line #%s) missing 2nd side!\n", lines[i].special, sizeu1(i));
+				else
+				{
+					lines[i].args[2] = sides[lines[i].sidenum[side]].textureoffset >> FRACBITS;
+					lines[i].args[3] = sides[lines[i].sidenum[side]].rowoffset >> FRACBITS;
+				}
+			}
+			else
+			{
+				lines[i].args[2] = lines[i].args[1];
+				lines[i].args[3] = lines[i].args[1];
+			}
+
+			if (lines[i].flags & ML_NETONLY)
+				lines[i].args[4] |= SL_NOPHYSICS;
+			if (lines[i].flags & ML_NONET)
+				lines[i].args[4] |= SL_DYNAMIC;
+
+			lines[i].special = 704;
+			break;
+		}
+		case 720: //Copy front side floor slope
+		case 721: //Copy front side ceiling slope
+		case 722: //Copy front side floor and ceiling slope
+			if (lines[i].special != 721)
+				lines[i].args[0] = lines[i].tag;
+			if (lines[i].special != 720)
+				lines[i].args[1] = lines[i].tag;
+			lines[i].special = 720;
+			break;
+		default:
+			break;
+		}
+	}
+}
+
 /** Compute MD5 message digest for bytes read from memory source
   *
   * The resulting message digest number will be written into the 16 bytes
@@ -2697,6 +2797,7 @@ static void P_MakeMapMD5(virtres_t *virt, void *dest)
 static boolean P_LoadMapFromFile(void)
 {
 	virtres_t *virt = vres_GetMap(lastloadedmaplumpnum);
+	virtlump_t *textmap = vres_Find(virt, "TEXTMAP");
 
 	if (!P_LoadMapData(virt))
 		return false;
@@ -2705,6 +2806,9 @@ static boolean P_LoadMapFromFile(void)
 
 	P_LinkMapData();
 
+	if (!textmap)
+		P_ConvertBinaryMap();
+
 	// Copy relevant map data for NetArchive purposes.
 	spawnsectors = Z_Calloc(numsectors * sizeof(*sectors), PU_LEVEL, NULL);
 	spawnlines = Z_Calloc(numlines * sizeof(*lines), PU_LEVEL, NULL);
diff --git a/src/p_slopes.c b/src/p_slopes.c
index 2cf2c74ba..f16975726 100644
--- a/src/p_slopes.c
+++ b/src/p_slopes.c
@@ -247,32 +247,30 @@ static void line_SpawnViaLine(const int linenum, const boolean spawnthinker)
 	// because checking to see if a slope had changed will waste more memory than
 	// if the slope was just updated when called
 	line_t *line = lines + linenum;
-	INT16 special = line->special;
 	pslope_t *fslope = NULL, *cslope = NULL;
 	vector3_t origin, point;
 	vector2_t direction;
 	fixed_t nx, ny, dz, extent;
 
-	boolean frontfloor = (special == 700 || special == 702 || special == 703);
-	boolean backfloor  = (special == 710 || special == 712 || special == 713);
-	boolean frontceil  = (special == 701 || special == 702 || special == 713);
-	boolean backceil   = (special == 711 || special == 712 || special == 703);
-
+	boolean frontfloor = line->args[0] == 1;
+	boolean backfloor = line->args[0] == 2;
+	boolean frontceil = line->args[1] == 1;
+	boolean backceil = line->args[1] == 2;
 	UINT8 flags = 0; // Slope flags
-	if (line->flags & ML_NETONLY)
+	if (line->args[2] & 1)
 		flags |= SL_NOPHYSICS;
-	if (line->flags & ML_NONET)
+	if (line->args[2] & 2)
 		flags |= SL_DYNAMIC;
 
 	if(!frontfloor && !backfloor && !frontceil && !backceil)
 	{
-		CONS_Printf("P_SpawnSlope_Line called with non-slope line special.\n");
+		CONS_Printf("line_SpawnViaLine: Slope special with nothing to do.\n");
 		return;
 	}
 
 	if(!line->frontsector || !line->backsector)
 	{
-		CONS_Debug(DBG_SETUP, "P_SpawnSlope_Line used on a line without two sides. (line number %i)\n", linenum);
+		CONS_Debug(DBG_SETUP, "line_SpawnViaLine: Slope special used on a line without two sides. (line number %i)\n", linenum);
 		return;
 	}
 
@@ -299,7 +297,7 @@ static void line_SpawnViaLine(const int linenum, const boolean spawnthinker)
 
 		if(extent < 0)
 		{
-			CONS_Printf("P_SpawnSlope_Line failed to get frontsector extent on line number %i\n", linenum);
+			CONS_Printf("line_SpawnViaLine failed to get frontsector extent on line number %i\n", linenum);
 			return;
 		}
 
@@ -365,7 +363,7 @@ static void line_SpawnViaLine(const int linenum, const boolean spawnthinker)
 
 		if(extent < 0)
 		{
-			CONS_Printf("P_SpawnSlope_Line failed to get backsector extent on line number %i\n", linenum);
+			CONS_Printf("line_SpawnViaLine failed to get backsector extent on line number %i\n", linenum);
 			return;
 		}
 
@@ -464,49 +462,81 @@ static void line_SpawnViaVertexes(const int linenum, const boolean spawnthinker)
 	line_t *line = lines + linenum;
 	side_t *side;
 	pslope_t **slopetoset;
-	UINT16 tag1, tag2, tag3;
-
-	UINT8 flags = 0;
-	if (line->flags & ML_NETONLY)
+	UINT16 tag1 = line->args[1];
+	UINT16 tag2 = line->args[2];
+	UINT16 tag3 = line->args[3];
+	UINT8 flags = 0; // Slope flags
+	if (line->args[4] & 1)
 		flags |= SL_NOPHYSICS;
-	if (line->flags & ML_NONET)
+	if (line->args[4] & 2)
 		flags |= SL_DYNAMIC;
 
-	switch(line->special)
+	switch(line->args[0])
 	{
-	case 704:
+	case 0:
 		slopetoset = &line->frontsector->f_slope;
 		side = &sides[line->sidenum[0]];
 		break;
-	case 705:
+	case 1:
 		slopetoset = &line->frontsector->c_slope;
 		side = &sides[line->sidenum[0]];
 		break;
-	case 714:
+	case 2:
 		slopetoset = &line->backsector->f_slope;
 		side = &sides[line->sidenum[1]];
 		break;
-	case 715:
+	case 3:
 		slopetoset = &line->backsector->c_slope;
 		side = &sides[line->sidenum[1]];
 	default:
 		return;
 	}
 
-	if (line->flags & ML_EFFECT6)
-	{
-		tag1 = line->tag;
-		tag2 = side->textureoffset >> FRACBITS;
-		tag3 = side->rowoffset >> FRACBITS;
-	}
-	else
-		tag1 = tag2 = tag3 = line->tag;
-
 	*slopetoset = MakeViaMapthings(tag1, tag2, tag3, flags, spawnthinker);
 
 	side->sector->hasslope = true;
 }
 
+static boolean P_SetSlopeFromTag(sector_t *sec, INT32 tag, boolean ceiling)
+{
+	INT32 i;
+	pslope_t **secslope = ceiling ? &sec->c_slope : &sec->f_slope;
+
+	if (!tag || *secslope)
+		return false;
+
+	for (i = -1; (i = P_FindSectorFromTag(tag, i)) >= 0;)
+	{
+		pslope_t *srcslope = ceiling ? sectors[i].c_slope : sectors[i].f_slope;
+		if (srcslope)
+		{
+			*secslope = srcslope;
+			return true;
+		}
+	}
+	return false;
+}
+
+static boolean P_CopySlope(pslope_t **toslope, pslope_t *fromslope)
+{
+	if (*toslope || !fromslope)
+		return true;
+
+	*toslope = fromslope;
+	return true;
+}
+
+static void P_UpdateHasSlope(sector_t *sec)
+{
+	size_t i;
+
+	sec->hasslope = true;
+
+	// if this is an FOF control sector, make sure any target sectors also are marked as having slopes
+	if (sec->numattached)
+		for (i = 0; i < sec->numattached; i++)
+			sectors[sec->attached[i]].hasslope = true;
+}
 
 //
 // P_CopySectorSlope
@@ -516,25 +546,31 @@ static void line_SpawnViaVertexes(const int linenum, const boolean spawnthinker)
 void P_CopySectorSlope(line_t *line)
 {
 	sector_t *fsec = line->frontsector;
-	int i, special = line->special;
+	sector_t *bsec = line->backsector;
+	boolean setfront = false;
+	boolean setback = false;
 
-	// Check for copy linedefs
-	for (i = -1; (i = P_FindSectorFromLineTag(line, i)) >= 0;)
+	setfront |= P_SetSlopeFromTag(fsec, line->args[0], false);
+	setfront |= P_SetSlopeFromTag(fsec, line->args[1], true);
+	if (bsec)
 	{
-		sector_t *srcsec = sectors + i;
+		setback |= P_SetSlopeFromTag(bsec, line->args[2], false);
+		setback |= P_SetSlopeFromTag(bsec, line->args[3], true);
 
-		if ((special - 719) & 1 && !fsec->f_slope && srcsec->f_slope)
-			fsec->f_slope = srcsec->f_slope; //P_CopySlope(srcsec->f_slope);
-		if ((special - 719) & 2 && !fsec->c_slope && srcsec->c_slope)
-			fsec->c_slope = srcsec->c_slope; //P_CopySlope(srcsec->c_slope);
+		if (line->args[4] & 1)
+			setback |= P_CopySlope(&bsec->f_slope, fsec->f_slope);
+		if (line->args[4] & 2)
+			setfront |= P_CopySlope(&fsec->f_slope, bsec->f_slope);
+		if (line->args[4] & 4)
+			setback |= P_CopySlope(&bsec->c_slope, fsec->c_slope);
+		if (line->args[4] & 8)
+			setfront |= P_CopySlope(&fsec->c_slope, bsec->c_slope);
 	}
 
-	fsec->hasslope = true;
-
-	// if this is an FOF control sector, make sure any target sectors also are marked as having slopes
-	if (fsec->numattached)
-		for (i = 0; i < (int)fsec->numattached; i++)
-			sectors[fsec->attached[i]].hasslope = true;
+	if (setfront)
+		P_UpdateHasSlope(fsec);
+	if (setback)
+		P_UpdateHasSlope(bsec);
 
 	line->special = 0; // Linedef was use to set slopes, it finished its job, so now make it a normal linedef
 }
@@ -563,20 +599,10 @@ void P_ResetDynamicSlopes(const boolean fromsave) {
 		switch (lines[i].special)
 		{
 			case 700:
-			case 701:
-			case 702:
-			case 703:
-			case 710:
-			case 711:
-			case 712:
-			case 713:
 				line_SpawnViaLine(i, !fromsave);
 				break;
 
 			case 704:
-			case 705:
-			case 714:
-			case 715:
 				line_SpawnViaVertexes(i, !fromsave);
 				break;
 
@@ -591,8 +617,6 @@ void P_ResetDynamicSlopes(const boolean fromsave) {
 		switch (lines[i].special)
 		{
 			case 720:
-			case 721:
-			case 722:
 				P_CopySectorSlope(&lines[i]);
 			default:
 				break;
diff --git a/src/r_defs.h b/src/r_defs.h
index 52b9bea95..677c34a9d 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -401,6 +401,8 @@ typedef enum
 
 #define HORIZONSPECIAL 41
 
+#define NUMLINEARGS 6
+
 typedef struct line_s
 {
 	// Vertices, from v1 to v2.
@@ -413,6 +415,7 @@ typedef struct line_s
 	INT16 flags;
 	INT16 special;
 	INT16 tag;
+	INT32 args[NUMLINEARGS];
 
 	// Visual appearance: sidedefs.
 	UINT16 sidenum[2]; // sidenum[1] will be 0xffff if one-sided