diff --git a/src/actor.h b/src/actor.h
index 5474a8213..7dccdc397 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -396,13 +396,11 @@ enum ActorFlag7
 	MF7_FORCEZERORADIUSDMG = 0x10000000,	// passes zero radius damage on to P_DamageMobj, this is necessary in some cases where DoSpecialDamage gets overrideen.
 	MF7_NOINFIGHTSPECIES = 0x20000000,	// don't start infights with one's own species.
 	MF7_FORCEINFIGHTING	= 0x40000000,	// overrides a map setting of 'no infighting'.
-	MF7_SPRITEFLIP		= 0x80000000,	// sprite flipped on x-axis
 };
 enum ActorFlag8
 {
 	MF8_FRIGHTENING		= 0x00000001,	// for those moments when halloween just won't do
 	MF8_INSCROLLSEC		= 0x00000002,	// actor is partially inside a scrolling sector
-	MF8_ZDOOMTRANS		= 0x00000004,	// is not normally transparent in Vanilla Doom
 };
 
 // --- mobj.renderflags ---
@@ -444,6 +442,10 @@ enum ActorRenderFlag
 	RF_INTERPOLATEANGLES		= 0x01000000, // [MC] Allow interpolation of the actor's angle, pitch and roll.
 	RF_MAYBEINVISIBLE	= 0x02000000,
 	RF_DONTINTERPOLATE	= 0x04000000,	// no render interpolation ever!
+
+	RF_SPRITEFLIP		= 0x08000000,	// sprite flipped on x-axis
+	RF_ZDOOMTRANS		= 0x10000000,	// is not normally transparent in Vanilla Doom
+	RF_ZDOOMADD		= 0x20000000,	// is not normally additive in Vanilla Hexen/Heretic/Strife
 };
 
 // This translucency value produces the closest match to Heretic's TINTTAB.
diff --git a/src/gl/scene/gl_sprite.cpp b/src/gl/scene/gl_sprite.cpp
index fa5b40dec..f6fecf0b1 100644
--- a/src/gl/scene/gl_sprite.cpp
+++ b/src/gl/scene/gl_sprite.cpp
@@ -75,7 +75,7 @@ CUSTOM_CVAR(Int, gl_fuzztype, 0, CVAR_ARCHIVE)
 }
 
 EXTERN_CVAR (Float, transsouls)
-EXTERN_CVAR (Bool, r_canontrans)
+EXTERN_CVAR (Bool, r_vanillatrans)
 
 extern TArray<spritedef_t> sprites;
 extern TArray<spriteframe_t> SpriteFrames;
@@ -801,7 +801,7 @@ void GLSprite::Process(AActor* thing, sector_t * sector, int thruportal)
 				sprangle = 0.;
 				rot = 0;
 			}
-			patch = sprites[spritenum].GetSpriteFrame(thing->frame, rot, sprangle, &mirror, !!(thing->flags7 & MF7_SPRITEFLIP));
+			patch = sprites[spritenum].GetSpriteFrame(thing->frame, rot, sprangle, &mirror, !!(thing->renderflags & RF_SPRITEFLIP));
 		}
 
 		if (!patch.isValid()) return;
@@ -817,7 +817,7 @@ void GLSprite::Process(AActor* thing, sector_t * sector, int thruportal)
 		gltexture->GetSpriteRect(&r);
 
 		// [SP] SpriteFlip
-		if (thing->flags7 & MF7_SPRITEFLIP)
+		if (thing->renderflags & RF_SPRITEFLIP)
 			thing->renderflags ^= RF_XFLIP;
 
 		if (mirror ^ !!(thing->renderflags & RF_XFLIP))
@@ -832,7 +832,7 @@ void GLSprite::Process(AActor* thing, sector_t * sector, int thruportal)
 			ur = gltexture->GetSpriteUL();
 		}
 
-		if (thing->flags7 & MF7_SPRITEFLIP) // [SP] Flip back
+		if (thing->renderflags & RF_SPRITEFLIP) // [SP] Flip back
 			thing->renderflags ^= RF_XFLIP;
 
 		r.Scale(sprscale.X, sprscale.Y);
@@ -993,14 +993,25 @@ void GLSprite::Process(AActor* thing, sector_t * sector, int thruportal)
 	{
 		trans = 1.f;
 	}
-	if ((thing->flags8 & MF8_ZDOOMTRANS) && r_canontrans)
-	{	// [SP] "canonical transparency" - with the flip of a CVar, disable transparency for Doom objects
-		trans = 1.f;
-		RenderStyle.BlendOp = STYLEOP_Add;
-		RenderStyle.SrcAlpha = STYLEALPHA_One;
-		RenderStyle.DestAlpha = STYLEALPHA_Zero;
-	}
+	if (r_vanillatrans)
+	{
+		// [SP] "canonical transparency" - with the flip of a CVar, disable transparency for Doom objects,
+		//   and disable 'additive' translucency for certain objects from other games.
+		if (thing->renderflags & RF_ZDOOMTRANS)
+		{
+			trans = 1.f;
+			RenderStyle.BlendOp = STYLEOP_Add;
+			RenderStyle.SrcAlpha = STYLEALPHA_One;
+			RenderStyle.DestAlpha = STYLEALPHA_Zero;
+		}
+		if (thing->renderflags & RF_ZDOOMADD)
+		{
+			RenderStyle.BlendOp = STYLEOP_Add;
+			RenderStyle.SrcAlpha = STYLEALPHA_Src;
+			RenderStyle.DestAlpha = STYLEALPHA_InvSrc;
+		}
 
+	}
 	if (trans >= 1.f - FLT_EPSILON && RenderStyle.BlendOp != STYLEOP_Shadow && (
 		(RenderStyle.SrcAlpha == STYLEALPHA_One && RenderStyle.DestAlpha == STYLEALPHA_Zero) ||
 		(RenderStyle.SrcAlpha == STYLEALPHA_Src && RenderStyle.DestAlpha == STYLEALPHA_InvSrc)
diff --git a/src/polyrenderer/scene/poly_sprite.cpp b/src/polyrenderer/scene/poly_sprite.cpp
index fb2c4ea28..398f37e7b 100644
--- a/src/polyrenderer/scene/poly_sprite.cpp
+++ b/src/polyrenderer/scene/poly_sprite.cpp
@@ -31,7 +31,7 @@
 
 EXTERN_CVAR(Float, transsouls)
 EXTERN_CVAR(Int, r_drawfuzz)
-EXTERN_CVAR (Bool, r_canontrans)
+EXTERN_CVAR (Bool, r_vanillatrans)
 
 bool RenderPolySprite::GetLine(AActor *thing, DVector2 &left, DVector2 &right)
 {
@@ -146,8 +146,10 @@ void RenderPolySprite::Render(const TriMatrix &worldToClip, const PolyClipPlane
 	args.SetStencilTestValue(stencilValue);
 	args.SetWriteStencil(true, stencilValue);
 	args.SetClipPlane(clipPlane);
-	if ((thing->flags8 & MF8_ZDOOMTRANS) && r_canontrans)
+	if ((thing->renderflags & RF_ZDOOMTRANS) && r_vanillatrans)
 		args.SetStyle(LegacyRenderStyles[STYLE_Normal], 1.0f, thing->fillcolor, thing->Translation, tex, fullbrightSprite);
+	else if ((thing->renderflags & RF_ZDOOMADD) && r_vanillatrans)
+		args.SetStyle(LegacyRenderStyles[STYLE_Translucent], thing->Alpha, thing->fillcolor, thing->Translation, tex, fullbrightSprite);
 	else
 		args.SetStyle(thing->RenderStyle, thing->Alpha, thing->fillcolor, thing->Translation, tex, fullbrightSprite);
 	args.SetSubsectorDepthTest(true);
diff --git a/src/r_data/renderstyle.cpp b/src/r_data/renderstyle.cpp
index 11943f46d..fc1905f91 100644
--- a/src/r_data/renderstyle.cpp
+++ b/src/r_data/renderstyle.cpp
@@ -38,7 +38,7 @@
 #include "serializer.h"
 
 CVAR (Bool, r_drawtrans, true, 0)
-CVAR (Bool, r_canontrans, false, CVAR_ARCHIVE)
+CVAR (Bool, r_vanillatrans, false, CVAR_ARCHIVE)
 CVAR (Int, r_drawfuzz, 1, CVAR_ARCHIVE)
 
 // Convert legacy render styles to flexible render styles.
diff --git a/src/scripting/thingdef_data.cpp b/src/scripting/thingdef_data.cpp
index d978136b8..e53a7d48a 100644
--- a/src/scripting/thingdef_data.cpp
+++ b/src/scripting/thingdef_data.cpp
@@ -322,10 +322,8 @@ static FFlagDef ActorFlagDefs[]=
 	DEFINE_FLAG(MF7, FORCEZERORADIUSDMG, AActor, flags7),
 	DEFINE_FLAG(MF7, NOINFIGHTSPECIES, AActor, flags7),
 	DEFINE_FLAG(MF7, FORCEINFIGHTING, AActor, flags7),
-	DEFINE_FLAG(MF7, SPRITEFLIP, AActor, flags7),
 
 	DEFINE_FLAG(MF8, FRIGHTENING, AActor, flags8),
-	DEFINE_FLAG(MF8, ZDOOMTRANS, AActor, flags8),
 
 	// Effect flags
 	DEFINE_FLAG(FX, VISIBILITYPULSE, AActor, effects),
@@ -347,6 +345,9 @@ static FFlagDef ActorFlagDefs[]=
 	DEFINE_FLAG(RF, YFLIP, AActor, renderflags),
 	DEFINE_FLAG(RF, INTERPOLATEANGLES, AActor, renderflags),
 	DEFINE_FLAG(RF, DONTINTERPOLATE, AActor, renderflags),
+	DEFINE_FLAG(RF, SPRITEFLIP, AActor, renderflags),
+	DEFINE_FLAG(RF, ZDOOMTRANS, AActor, renderflags),
+	DEFINE_FLAG(RF, ZDOOMADD, AActor, renderflags),
 
 	// Bounce flags
 	DEFINE_FLAG2(BOUNCE_Walls, BOUNCEONWALLS, AActor, BounceFlags),
diff --git a/src/swrenderer/scene/r_opaque_pass.cpp b/src/swrenderer/scene/r_opaque_pass.cpp
index 1838122d0..bb8081a27 100644
--- a/src/swrenderer/scene/r_opaque_pass.cpp
+++ b/src/swrenderer/scene/r_opaque_pass.cpp
@@ -1007,7 +1007,7 @@ namespace swrenderer
 				DAngle sprangle = thing->GetSpriteAngle((sprite.pos - viewpoint.Pos).Angle(), viewpoint.TicFrac);
 				bool flipX;
 
-				FTextureID tex = sprdef->GetSpriteFrame(thing->frame, -1, sprangle, &flipX, !!(thing->flags7 & MF7_SPRITEFLIP));
+				FTextureID tex = sprdef->GetSpriteFrame(thing->frame, -1, sprangle, &flipX, !!(thing->renderflags & RF_SPRITEFLIP));
 				if (tex.isValid())
 				{
 					if (flipX)
diff --git a/src/swrenderer/things/r_sprite.cpp b/src/swrenderer/things/r_sprite.cpp
index c7c2898ba..7dcab13ec 100644
--- a/src/swrenderer/things/r_sprite.cpp
+++ b/src/swrenderer/things/r_sprite.cpp
@@ -68,7 +68,7 @@
 
 EXTERN_CVAR(Bool, r_fullbrightignoresectorcolor)
 EXTERN_CVAR(Bool, gl_light_sprites)
-EXTERN_CVAR (Bool, r_canontrans)
+EXTERN_CVAR (Bool, r_vanillatrans)
 
 namespace swrenderer
 {
@@ -147,7 +147,7 @@ namespace swrenderer
 		renderflags ^= renderportal->MirrorFlags & RF_XFLIP;
 
 		// [SP] SpriteFlip
-		if (thing->flags7 & MF7_SPRITEFLIP)
+		if (thing->renderflags & RF_SPRITEFLIP)
 			renderflags ^= RF_XFLIP;
 
 		// calculate edges of the shape
@@ -213,8 +213,13 @@ namespace swrenderer
 		if (thing->flags5 & MF5_BRIGHT)
 			vis->renderflags |= RF_FULLBRIGHT; // kg3D
 		vis->RenderStyle = thing->RenderStyle;
-		if ((thing->flags8 & MF8_ZDOOMTRANS) && r_canontrans)
-			vis->RenderStyle = LegacyRenderStyles[STYLE_Normal];
+		if (r_vanillatrans)
+		{
+			if (thing->renderflags & RF_ZDOOMTRANS)
+				vis->RenderStyle = LegacyRenderStyles[STYLE_Normal];
+			if (thing->renderflags & RF_ZDOOMADD)
+				vis->RenderStyle = LegacyRenderStyles[STYLE_Translucent];
+		}
 		vis->FillColor = thing->fillcolor;
 		vis->Translation = thing->Translation;		// [RH] thing translation table
 		vis->FakeFlatStat = fakeside;
diff --git a/wadsrc/static/zscript/heretic/beast.txt b/wadsrc/static/zscript/heretic/beast.txt
index 209b2da56..9e004f5c1 100644
--- a/wadsrc/static/zscript/heretic/beast.txt
+++ b/wadsrc/static/zscript/heretic/beast.txt
@@ -75,6 +75,7 @@ class BeastBall : Actor
 		-NOBLOCKMAP
 		+WINDTHRUST
 		+SPAWNSOUNDSOURCE
+		+ZDOOMADD
 		RenderStyle "Add";
 		SeeSound "beast/attack";
 	}
@@ -104,6 +105,7 @@ class Puffy : Actor
 		+MISSILE
 		+NOTELEPORT
 		+DONTSPLASH
+		+ZDOOMADD
 		RenderStyle "Add";
 	}
 	States