diff --git a/src/p_xlat.cpp b/src/p_xlat.cpp
index e61dcd52f0..7824adf2c4 100644
--- a/src/p_xlat.cpp
+++ b/src/p_xlat.cpp
@@ -118,11 +118,6 @@ void P_TranslateLineDef (line_t *ld, maplinedef_t *mld)
 	if (linetrans != NULL && linetrans->special != 0)
 	{
 		ld->special = linetrans->special;
-		ld->args[0] = linetrans->args[0];
-		ld->args[1] = linetrans->args[1];
-		ld->args[2] = linetrans->args[2];
-		ld->args[3] = linetrans->args[3];
-		ld->args[4] = linetrans->args[4];
 
 		ld->flags = flags | ((linetrans->flags & 0x1f) << 9);
 		if (linetrans->flags & 0x20) ld->flags |= ML_FIRSTSIDEONLY;
@@ -134,30 +129,17 @@ void P_TranslateLineDef (line_t *ld, maplinedef_t *mld)
 		{
 			ld->activation = SPAC_UseThrough;
 		}
-		switch (linetrans->flags & LINETRANS_TAGMASK)
+		// Set special arguments.
+		for (int t = 0; t < LINETRANS_MAXARGS; ++t)
 		{
-		case LINETRANS_HAS2TAGS:	// First two arguments are tags
-			ld->args[1] = tag;
-		case LINETRANS_HASTAGAT1:	// First argument is a tag
-			ld->args[0] = tag;
-			break;
-
-		case LINETRANS_HASTAGAT2:	// Second argument is a tag
-			ld->args[1] = tag;
-			break;
-
-		case LINETRANS_HASTAGAT3:	// Third argument is a tag
-			ld->args[2] = tag;
-			break;
-
-		case LINETRANS_HASTAGAT4:	// Fourth argument is a tag
-			ld->args[3] = tag;
-			break;
-
-		case LINETRANS_HASTAGAT5:	// Fifth argument is a tag
-			ld->args[4] = tag;
-			break;
+			ld->args[t] = linetrans->args[t];
+			// Arguments that are tags have the tag's value added to them.
+			if (linetrans->flags & (1 << (LINETRANS_TAGSHIFT+t)))
+			{
+				ld->args[t] += tag;
+			}
 		}
+
 		if ((ld->flags & ML_SECRET) && ld->activation & (SPAC_Use|SPAC_UseThrough))
 		{
 			ld->flags &= ~ML_MONSTERSCANACTIVATE;
diff --git a/src/xlat/parse_xlat.cpp b/src/xlat/parse_xlat.cpp
index 5edcde581c..e5d2772659 100644
--- a/src/xlat/parse_xlat.cpp
+++ b/src/xlat/parse_xlat.cpp
@@ -67,9 +67,16 @@ FLineFlagTrans LineFlagTranslations[16];
 struct SpecialArgs
 {
 	int addflags;
+	int argcount;
 	int args[5];
 };
 
+struct SpecialArg
+{
+	int arg;
+	bool bIsTag;
+};
+
 struct ListFilter
 {
 	WORD filter;
diff --git a/src/xlat/xlat.h b/src/xlat/xlat.h
index 018a2639ed..0d020e75e8 100644
--- a/src/xlat/xlat.h
+++ b/src/xlat/xlat.h
@@ -6,14 +6,8 @@
 
 enum
 {
-	LINETRANS_HASTAGAT1	= (1<<6),		// (tag, x, x, x, x)
-	LINETRANS_HASTAGAT2	= (2<<6),		// (x, tag, x, x, x)
-	LINETRANS_HASTAGAT3	= (3<<6),		// (x, x, tag, x, x)
-	LINETRANS_HASTAGAT4	= (4<<6),		// (x, x, x, tag, x)
-	LINETRANS_HASTAGAT5	= (5<<6),		// (x, x, x, x, tag)
-
-	LINETRANS_HAS2TAGS	= (7<<6),		// (tag, tag, x, x, x)
-	LINETRANS_TAGMASK	= (7<<6)
+	LINETRANS_TAGSHIFT	= 24,
+	LINETRANS_MAXARGS	= 5
 };
 
 struct FLineTrans
diff --git a/src/xlat/xlat_parser.y b/src/xlat/xlat_parser.y
index d6f71b6a30..046a950c9c 100644
--- a/src/xlat/xlat_parser.y
+++ b/src/xlat/xlat_parser.y
@@ -99,228 +99,71 @@ linetype_declaration ::= exp EQUALS exp COMMA SYM(S) LPAREN special_args RPAREN.
 	Printf ("%s, line %d: %s is undefined\n", context->SourceFile, context->SourceLine, S.sym);
 }
 
+%type special_arg {SpecialArg}
+
+special_arg(Z) ::= exp(A).
+{
+	Z.arg = A;
+	Z.bIsTag = false;
+}
+special_arg(Z) ::= TAG.
+{
+	Z.arg = 0;
+	Z.bIsTag = true;
+}
+special_arg(Z) ::= TAG PLUS exp(A).
+{
+	Z.arg = A;
+	Z.bIsTag = true;
+}
+special_arg(Z) ::= TAG MINUS exp(A).
+{
+	Z.arg = -A;
+	Z.bIsTag = true;
+}
+
+%type multi_special_arg {SpecialArgs}
+
+multi_special_arg(Z) ::= special_arg(A).
+{
+	Z.addflags = A.bIsTag << LINETRANS_TAGSHIFT;
+	Z.argcount = 1;
+	Z.args[0] = A.arg;
+	Z.args[1] = 0;
+	Z.args[2] = 0;
+	Z.args[3] = 0;
+	Z.args[4] = 0;
+}
+multi_special_arg(Z) ::= multi_special_arg(A) COMMA special_arg(B).
+{
+	Z = A;
+	if (Z.argcount < LINETRANS_MAXARGS)
+	{
+		Z.addflags |= B.bIsTag << (LINETRANS_TAGSHIFT + Z.argcount);
+		Z.args[Z.argcount] = B.arg;
+		Z.argcount++;
+	}
+	else if (Z.argcount++ == LINETRANS_MAXARGS)
+	{
+		context->PrintError("Line special has too many arguments\n");
+	}
+}
+
 %type special_args {SpecialArgs}
 
 special_args(Z) ::= . /* empty */
 {
 	Z.addflags = 0;
+	Z.argcount = 0;
 	Z.args[0] = 0;
 	Z.args[1] = 0;
 	Z.args[2] = 0;
 	Z.args[3] = 0;
 	Z.args[4] = 0;
 }
-special_args(Z) ::= TAG.
+special_args(Z) ::= multi_special_arg(A).
 {
-	Z.addflags = LINETRANS_HASTAGAT1;
-	Z.args[0] = 0;
-	Z.args[1] = 0;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA exp(B).
-{
-	Z.addflags = LINETRANS_HASTAGAT1;
-	Z.args[0] = 0;
-	Z.args[1] = B;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA exp(B) COMMA exp(C).
-{
-	Z.addflags = LINETRANS_HASTAGAT1;
-	Z.args[0] = 0;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA exp(B) COMMA exp(C) COMMA exp(D).
-{
-	Z.addflags = LINETRANS_HASTAGAT1;
-	Z.args[0] = 0;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA exp(B) COMMA exp(C) COMMA exp(D) COMMA exp(E).
-{
-	Z.addflags = LINETRANS_HASTAGAT1;
-	Z.args[0] = 0;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = E;
-}
-special_args(Z) ::= TAG COMMA TAG.
-{
-	Z.addflags = LINETRANS_HAS2TAGS;
-	Z.args[0] = Z.args[1] = 0;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA TAG COMMA exp(C).
-{
-	Z.addflags = LINETRANS_HAS2TAGS;
-	Z.args[0] = Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA TAG COMMA exp(C) COMMA exp(D).
-{
-	Z.addflags = LINETRANS_HAS2TAGS;
-	Z.args[0] = Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= TAG COMMA TAG COMMA exp(C) COMMA exp(D) COMMA exp(E).
-{
-	Z.addflags = LINETRANS_HAS2TAGS;
-	Z.args[0] = Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = E;
-}
-special_args(Z) ::= exp(A).
-{
-	Z.addflags = 0;
-	Z.args[0] = A;
-	Z.args[1] = 0;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B).
-{
-	Z.addflags = 0;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C).
-{
-	Z.addflags = 0;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C) COMMA exp(D).
-{
-	Z.addflags = 0;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C) COMMA exp(D) COMMA exp(E).
-{
-	Z.addflags = 0;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = E;
-}
-special_args(Z) ::= exp(A) COMMA TAG.
-{
-	Z.addflags = LINETRANS_HASTAGAT2;
-	Z.args[0] = A;
-	Z.args[1] = 0;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA TAG COMMA exp(C).
-{
-	Z.addflags = LINETRANS_HASTAGAT2;
-	Z.args[0] = A;
-	Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA TAG COMMA exp(C) COMMA exp(D).
-{
-	Z.addflags = LINETRANS_HASTAGAT2;
-	Z.args[0] = A;
-	Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA TAG COMMA exp(C) COMMA exp(D) COMMA exp(E).
-{
-	Z.addflags = LINETRANS_HASTAGAT2;
-	Z.args[0] = A;
-	Z.args[1] = 0;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = E;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA TAG.
-{
-	Z.addflags = LINETRANS_HASTAGAT3;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = 0;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA TAG COMMA exp(D).
-{
-	Z.addflags = LINETRANS_HASTAGAT3;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = 0;
-	Z.args[3] = D;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA TAG COMMA exp(D) COMMA exp(E).
-{
-	Z.addflags = LINETRANS_HASTAGAT3;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = 0;
-	Z.args[3] = D;
-	Z.args[4] = E;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C) COMMA TAG.
-{
-	Z.addflags = LINETRANS_HASTAGAT4;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = 0;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C) COMMA TAG COMMA exp(E).
-{
-	Z.addflags = LINETRANS_HASTAGAT4;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = 0;
-	Z.args[4] = E;
-}
-special_args(Z) ::= exp(A) COMMA exp(B) COMMA exp(C) COMMA exp(D) COMMA TAG.
-{
-	Z.addflags = LINETRANS_HASTAGAT5;
-	Z.args[0] = A;
-	Z.args[1] = B;
-	Z.args[2] = C;
-	Z.args[3] = D;
-	Z.args[4] = 0;
+	Z = A;
 }
 
 //==========================================================================
@@ -463,7 +306,7 @@ list_val(A) ::= exp(B) COLON exp(C).
 maxlinespecial_def ::= MAXLINESPECIAL EQUALS exp(mx) SEMICOLON.
 {
 	// Just kill all specials higher than the max.
-	// If the translator wants to redefine some later, just let it.s
+	// If the translator wants to redefine some later, just let it.
 	SimpleLineTranslations.Resize(mx+1);
 }