diff --git a/src/actor.h b/src/actor.h
index 46d9ae0465..b371fdaee8 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -1265,6 +1265,10 @@ public:
 	{
 		z = newz;
 	}
+	void AddZ(fixed_t newz, bool moving = true)
+	{
+		z += newz;
+	}
 
 	// These are not for general use as they do not link the actor into the world!
 	void SetXY(fixed_t xx, fixed_t yy)
diff --git a/src/g_hexen/a_flies.cpp b/src/g_hexen/a_flies.cpp
index 683cbebe1d..05c4ef94c0 100644
--- a/src/g_hexen/a_flies.cpp
+++ b/src/g_hexen/a_flies.cpp
@@ -83,7 +83,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_FlyBuzz)
 	self->angle = ang;
 	self->args[0]++;
 	ang >>= ANGLETOFINESHIFT;
-	if (!P_TryMove(self, self->x + 6 * finecosine[ang], self->y + 6 * finesine[ang], true))
+	if (!P_TryMove(self, self->X() + 6 * finecosine[ang], self->Y() + 6 * finesine[ang], true))
 	{
 		self->SetIdle(true);
 		return;
@@ -94,7 +94,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_FlyBuzz)
 		self->vely += (pr_fly() - 128) << BOBTOFINESHIFT;
 	}
 	int zrand = pr_fly();
-	if (targ->z + 5*FRACUNIT < self->z && zrand > 150)
+	if (targ->Z() + 5*FRACUNIT < self->Z() && zrand > 150)
 	{
 		zrand = -zrand;
 	}
diff --git a/src/g_hexen/a_fog.cpp b/src/g_hexen/a_fog.cpp
index 6bafd383c3..a427daa47d 100644
--- a/src/g_hexen/a_fog.cpp
+++ b/src/g_hexen/a_fog.cpp
@@ -41,7 +41,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_FogSpawn)
 
 	self->special1 = self->args[2];		// Reset frequency count
 
-	mo = Spawn (fogs[pr_fogspawn()%3], self->x, self->y, self->z, ALLOW_REPLACE);
+	mo = Spawn (fogs[pr_fogspawn()%3], self->Pos(), ALLOW_REPLACE);
 
 	if (mo)
 	{
@@ -80,7 +80,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_FogMove)
 	if ((self->args[3] % 4) == 0)
 	{
 		weaveindex = self->special2;
-		self->z += finesine[weaveindex << BOBTOFINESHIFT] * 4;
+		self->AddZ(finesine[weaveindex << BOBTOFINESHIFT] * 4);
 		self->special2 = (weaveindex + 1) & 63;
 	}
 
diff --git a/src/g_hexen/a_heresiarch.cpp b/src/g_hexen/a_heresiarch.cpp
index 498b4e9554..e2b8c9ed27 100644
--- a/src/g_hexen/a_heresiarch.cpp
+++ b/src/g_hexen/a_heresiarch.cpp
@@ -232,7 +232,6 @@ void ASorcBall1::DoFireSpell ()
 DEFINE_ACTION_FUNCTION(AActor, A_SorcSpinBalls)
 {
 	AActor *mo;
-	fixed_t z;
 
 	self->SpawnState += 2;		// [RH] Don't spawn balls again
 	A_SlowBalls(self);
@@ -240,17 +239,18 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcSpinBalls)
 	self->args[3] = SORC_NORMAL;
 	self->args[4] = SORCBALL_INITIAL_SPEED;		// Initial orbit speed
 	self->special1 = ANGLE_1;
-	z = self->z - self->floorclip + self->height;
+
+	fixedvec3 pos = self->PosPlusZ(-self->floorclip + self->height);
 	
-	mo = Spawn("SorcBall1", self->x, self->y, z, NO_REPLACE);
+	mo = Spawn("SorcBall1", pos, NO_REPLACE);
 	if (mo)
 	{
 		mo->target = self;
 		mo->special2 = SORCFX4_RAPIDFIRE_TIME;
 	}
-	mo = Spawn("SorcBall2", self->x, self->y, z, NO_REPLACE);
+	mo = Spawn("SorcBall2", pos, NO_REPLACE);
 	if (mo) mo->target = self;
-	mo = Spawn("SorcBall3", self->x, self->y, z, NO_REPLACE);
+	mo = Spawn("SorcBall3", pos, NO_REPLACE);
 	if (mo) mo->target = self;
 }
 
@@ -271,7 +271,6 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcBallOrbit)
 	}
 
 	ASorcBall *actor;
-	int x,y;
 	angle_t angle, baseangle;
 	int mode = self->target->args[3];
 	AHeresiarch *parent = barrier_cast<AHeresiarch *>(self->target);
@@ -370,9 +369,12 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcBallOrbit)
 		S_Sound (actor, CHAN_BODY, "SorcererBallWoosh", 1, ATTN_NORM);
 	}
 	actor->special1 = angle;		// Set previous angle
-	x = parent->x + FixedMul(dist, finecosine[angle]);
-	y = parent->y + FixedMul(dist, finesine[angle]);
-	actor->SetOrigin (x, y, parent->z - parent->floorclip + parent->height);
+
+	fixedvec3 pos = parent->Vec3Offset(
+		FixedMul(dist, finecosine[angle]),
+		FixedMul(dist, finesine[angle]),
+		-parent->floorclip + parent->height);
+	actor->SetOrigin (pos, true);
 	actor->floorz = parent->floorz;
 	actor->ceilingz = parent->ceilingz;
 }
@@ -540,8 +542,7 @@ void ASorcBall2::CastSorcererSpell ()
 	AActor *parent = target;
 	AActor *mo;
 
-	fixed_t z = parent->z - parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT;
-	mo = Spawn("SorcFX2", x, y, z, ALLOW_REPLACE);
+	mo = Spawn("SorcFX2", PosPlusZ(-parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT), ALLOW_REPLACE);
 	parent->flags2 |= MF2_REFLECTIVE|MF2_INVULNERABLE;
 	parent->args[0] = SORC_DEFENSE_TIME;
 	if (mo) mo->target = parent;
@@ -667,7 +668,7 @@ void A_SorcOffense2(AActor *actor)
 		mo->special2 = 35*5/2;		// 5 seconds
 		dist = mo->AproxDistance(dest) / mo->Speed;
 		if(dist < 1) dist = 1;
-		mo->velz = (dest->z - mo->z) / dist;
+		mo->velz = (dest->Z() - mo->Z()) / dist;
 	}
 }
 
@@ -695,23 +696,19 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcBossAttack)
 
 DEFINE_ACTION_FUNCTION(AActor, A_SpawnFizzle)
 {
-	fixed_t x,y,z;
 	fixed_t dist = 5*FRACUNIT;
-	angle_t angle = self->angle >> ANGLETOFINESHIFT;
 	fixed_t speed = self->Speed;
 	angle_t rangle;
 	AActor *mo;
 	int ix;
 
-	x = self->x + FixedMul(dist,finecosine[angle]);
-	y = self->y + FixedMul(dist,finesine[angle]);
-	z = self->z - self->floorclip + (self->height>>1);
+	fixedvec3 pos = self->Vec3Angle(dist, self->angle, -self->floorclip + (self->height >> 1));
 	for (ix=0; ix<5; ix++)
 	{
-		mo = Spawn("SorcSpark1", x, y, z, ALLOW_REPLACE);
+		mo = Spawn("SorcSpark1", pos, ALLOW_REPLACE);
 		if (mo)
 		{
-			rangle = angle + ((pr_heresiarch()%5) << 1);
+			rangle = (self->angle >> ANGLETOFINESHIFT) + ((pr_heresiarch()%5) << 1);
 			mo->velx = FixedMul(pr_heresiarch()%speed, finecosine[rangle]);
 			mo->vely = FixedMul(pr_heresiarch()%speed, finesine[rangle]);
 			mo->velz = FRACUNIT*2;
@@ -755,7 +752,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Split)
 {
 	AActor *mo;
 
-	mo = Spawn(self->GetClass(), self->x, self->y, self->z, NO_REPLACE);
+	mo = Spawn(self->GetClass(), self->Pos(), NO_REPLACE);
 	if (mo)
 	{
 		mo->target = self->target;
@@ -763,7 +760,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Split)
 		mo->special1 = self->angle;					// Set angle
 		mo->SetState (mo->FindState("Orbit"));
 	}
-	mo = Spawn(self->GetClass(), self->x, self->y, self->z, NO_REPLACE);
+	mo = Spawn(self->GetClass(), self->Pos(), NO_REPLACE);
 	if (mo)
 	{
 		mo->target = self->target;
@@ -785,7 +782,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Split)
 DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Orbit)
 {
 	angle_t angle;
-	fixed_t x,y,z;
+	fixedvec3 pos;
 	AActor *parent = self->target;
 
 	// [RH] If no parent, then disappear
@@ -818,26 +815,28 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Orbit)
 	{
 		self->special1 += ANGLE_1*10;
 		angle = ((angle_t)self->special1) >> ANGLETOFINESHIFT;
-		x = parent->x + FixedMul(dist, finecosine[angle]);
-		y = parent->y + FixedMul(dist, finesine[angle]);
-		z = parent->z - parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT;
-		z += FixedMul(15*FRACUNIT,finecosine[angle]);
+		pos = parent->Vec3Offset(
+			FixedMul(dist, finecosine[angle]),
+			FixedMul(dist, finesine[angle]),
+			parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT);
+		pos.z += FixedMul(15*FRACUNIT,finecosine[angle]);
 		// Spawn trailer
-		Spawn("SorcFX2T1", x, y, z, ALLOW_REPLACE);
+		Spawn("SorcFX2T1", pos, ALLOW_REPLACE);
 	}
 	else							// Clock wise
 	{
 		self->special1 -= ANGLE_1*10;
 		angle = ((angle_t)self->special1) >> ANGLETOFINESHIFT;
-		x = parent->x + FixedMul(dist, finecosine[angle]);
-		y = parent->y + FixedMul(dist, finesine[angle]);
-		z = parent->z - parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT;
-		z += FixedMul(20*FRACUNIT,finesine[angle]);
+		pos = parent->Vec3Offset(
+			FixedMul(dist, finecosine[angle]),
+			FixedMul(dist, finesine[angle]),
+			parent->floorclip + SORC_DEFENSE_HEIGHT*FRACUNIT);
+		pos.z += FixedMul(20*FRACUNIT,finesine[angle]);
 		// Spawn trailer
-		Spawn("SorcFX2T1", x, y, z, ALLOW_REPLACE);
+		Spawn("SorcFX2T1", pos, ALLOW_REPLACE);
 	}
 
-	self->SetOrigin (x, y, z);
+	self->SetOrigin (pos, true);
 	self->floorz = parent->floorz;
 	self->ceilingz = parent->ceilingz;
 }
@@ -853,7 +852,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SorcFX2Orbit)
 DEFINE_ACTION_FUNCTION(AActor, A_SpawnBishop)
 {
 	AActor *mo;
-	mo = Spawn("Bishop", self->x, self->y, self->z, ALLOW_REPLACE);
+	mo = Spawn("Bishop", self->Pos(), ALLOW_REPLACE);
 	if (mo)
 	{
 		if (!P_TestMobjLocation(mo))
@@ -878,7 +877,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SpawnBishop)
 
 DEFINE_ACTION_FUNCTION(AActor, A_SorcererBishopEntry)
 {
-	Spawn("SorcFX3Explosion", self->x, self->y, self->z, ALLOW_REPLACE);
+	Spawn("SorcFX3Explosion", self->Pos(), ALLOW_REPLACE);
 	S_Sound (self, CHAN_VOICE, self->SeeSound, 1, ATTN_NORM);
 }
 
diff --git a/src/g_hexen/a_hexenspecialdecs.cpp b/src/g_hexen/a_hexenspecialdecs.cpp
index ad10a464c1..19cb4f7525 100644
--- a/src/g_hexen/a_hexenspecialdecs.cpp
+++ b/src/g_hexen/a_hexenspecialdecs.cpp
@@ -60,7 +60,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_PotteryExplode)
 
 	for(i = (pr_pottery()&3)+3; i; i--)
 	{
-		mo = Spawn ("PotteryBit", self->x, self->y, self->z, ALLOW_REPLACE);
+		mo = Spawn ("PotteryBit", self->Pos(), ALLOW_REPLACE);
 		if (mo)
 		{
 			mo->SetState (mo->SpawnState + (pr_pottery()%5));
@@ -77,7 +77,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_PotteryExplode)
 		if (!((level.flags2 & LEVEL2_NOMONSTERS) || (dmflags & DF_NO_MONSTERS))
 		|| !(GetDefaultByType (type)->flags3 & MF3_ISMONSTER))
 		{ // Only spawn monsters if not -nomonsters
-			Spawn (type, self->x, self->y, self->z, ALLOW_REPLACE);
+			Spawn (type, self->Pos(), ALLOW_REPLACE);
 		}
 	}
 }
@@ -132,7 +132,7 @@ IMPLEMENT_CLASS (AZCorpseLynchedNoHeart)
 void AZCorpseLynchedNoHeart::PostBeginPlay ()
 {
 	Super::PostBeginPlay ();
-	Spawn ("BloodPool", x, y, floorz, ALLOW_REPLACE);
+	Spawn ("BloodPool", X(), Y(), floorz, ALLOW_REPLACE);
 }
 
 //============================================================================
@@ -145,7 +145,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_CorpseBloodDrip)
 {
 	if (pr_drip() <= 128)
 	{
-		Spawn ("CorpseBloodDrip", self->x, self->y, self->z + self->height/2, ALLOW_REPLACE);
+		Spawn ("CorpseBloodDrip", self->PosPlusZ(self->height/2), ALLOW_REPLACE);
 	}
 }
 
@@ -162,7 +162,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_CorpseExplode)
 
 	for (i = (pr_foo()&3)+3; i; i--)
 	{
-		mo = Spawn ("CorpseBit", self->x, self->y, self->z, ALLOW_REPLACE);
+		mo = Spawn ("CorpseBit", self->Pos(), ALLOW_REPLACE);
 		if (mo)
 		{
 			mo->SetState (mo->SpawnState + (pr_foo()%3));
@@ -172,7 +172,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_CorpseExplode)
 		}
 	}
 	// Spawn a skull
-	mo = Spawn ("CorpseBit", self->x, self->y, self->z, ALLOW_REPLACE);
+	mo = Spawn ("CorpseBit", self->Pos(), ALLOW_REPLACE);
 	if (mo)
 	{
 		mo->SetState (mo->SpawnState + 3);
@@ -198,9 +198,10 @@ DEFINE_ACTION_FUNCTION(AActor, A_LeafSpawn)
 	for (i = (pr_leaf()&3)+1; i; i--)
 	{
 		mo = Spawn (pr_leaf()&1 ? PClass::FindClass ("Leaf1") : PClass::FindClass ("Leaf2"),
-			self->x + (pr_leaf.Random2()<<14),
-			self->y + (pr_leaf.Random2()<<14),
-			self->z + (pr_leaf()<<14), ALLOW_REPLACE);
+			self->Vec3Offset(
+			(pr_leaf.Random2()<<14),
+			(pr_leaf.Random2()<<14),
+			(pr_leaf()<<14)), ALLOW_REPLACE);
 		if (mo)
 		{
 			P_ThrustMobj (mo, self->angle, (pr_leaf()<<9)+3*FRACUNIT);
@@ -277,9 +278,10 @@ DEFINE_ACTION_FUNCTION(AActor, A_SoAExplode)
 
 	for (i = 0; i < 10; i++)
 	{
-		mo = Spawn ("ZArmorChunk", self->x+((pr_soaexplode()-128)<<12),
-			self->y+((pr_soaexplode()-128)<<12), 
-			self->z+(pr_soaexplode()*self->height/256), ALLOW_REPLACE);
+		mo = Spawn ("ZArmorChunk", self->Vec3Offset(
+			((pr_soaexplode()-128)<<12),
+			((pr_soaexplode()-128)<<12), 
+			(pr_soaexplode()*self->height/256)), ALLOW_REPLACE);
 		if (mo)
 		{
 			mo->SetState (mo->SpawnState + i);
@@ -295,7 +297,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SoAExplode)
 		if (!((level.flags2 & LEVEL2_NOMONSTERS) || (dmflags & DF_NO_MONSTERS))
 		|| !(GetDefaultByType (type)->flags3 & MF3_ISMONSTER))
 		{ // Only spawn monsters if not -nomonsters
-			Spawn (type, self->x, self->y, self->z, ALLOW_REPLACE);
+			Spawn (type, self->Pos(), ALLOW_REPLACE);
 		}
 	}
 	S_Sound (self, CHAN_BODY, self->DeathSound, 1, ATTN_NORM);
diff --git a/src/g_hexen/a_iceguy.cpp b/src/g_hexen/a_iceguy.cpp
index 9d8360d4d5..75be577bf7 100644
--- a/src/g_hexen/a_iceguy.cpp
+++ b/src/g_hexen/a_iceguy.cpp
@@ -35,10 +35,10 @@ DEFINE_ACTION_FUNCTION(AActor, A_IceGuyLook)
 		dist = ((pr_iceguylook()-128)*self->radius)>>7;
 		an = (self->angle+ANG90)>>ANGLETOFINESHIFT;
 
-		Spawn (WispTypes[pr_iceguylook()&1],
-			self->x+FixedMul(dist, finecosine[an]),
-			self->y+FixedMul(dist, finesine[an]),
-			self->z+60*FRACUNIT, ALLOW_REPLACE);
+		Spawn(WispTypes[pr_iceguylook() & 1], self->Vec3Offset(
+			FixedMul(dist, finecosine[an]),
+			FixedMul(dist, finesine[an]),
+			60 * FRACUNIT), ALLOW_REPLACE);
 	}
 }
 
@@ -60,10 +60,10 @@ DEFINE_ACTION_FUNCTION(AActor, A_IceGuyChase)
 		dist = ((pr_iceguychase()-128)*self->radius)>>7;
 		an = (self->angle+ANG90)>>ANGLETOFINESHIFT;
 
-		mo = Spawn (WispTypes[pr_iceguychase()&1],
-			self->x+FixedMul(dist, finecosine[an]),
-			self->y+FixedMul(dist, finesine[an]),
-			self->z+60*FRACUNIT, ALLOW_REPLACE);
+		mo = Spawn(WispTypes[pr_iceguychase() & 1], self->Vec3Offset(
+			FixedMul(dist, finecosine[an]),
+			FixedMul(dist, finesine[an]),
+			60 * FRACUNIT), ALLOW_REPLACE);
 		if (mo)
 		{
 			mo->velx = self->velx;
@@ -82,22 +82,12 @@ DEFINE_ACTION_FUNCTION(AActor, A_IceGuyChase)
 
 DEFINE_ACTION_FUNCTION(AActor, A_IceGuyAttack)
 {
-	fixed_t an;
-
 	if(!self->target) 
 	{
 		return;
 	}
-	an = (self->angle+ANG90)>>ANGLETOFINESHIFT;
-	P_SpawnMissileXYZ(self->x+FixedMul(self->radius>>1,
-		finecosine[an]), self->y+FixedMul(self->radius>>1,
-		finesine[an]), self->z+40*FRACUNIT, self, self->target,
-		PClass::FindClass ("IceGuyFX"));
-	an = (self->angle-ANG90)>>ANGLETOFINESHIFT;
-	P_SpawnMissileXYZ(self->x+FixedMul(self->radius>>1,
-		finecosine[an]), self->y+FixedMul(self->radius>>1,
-		finesine[an]), self->z+40*FRACUNIT, self, self->target,
-		PClass::FindClass ("IceGuyFX"));
+	P_SpawnMissileXYZ(self->Vec3Angle(self->radius>>1, self->angle+ANG90, 40*FRACUNIT), self, self->target, PClass::FindClass ("IceGuyFX"));
+	P_SpawnMissileXYZ(self->Vec3Angle(self->radius>>1, self->angle-ANG90, 40*FRACUNIT), self, self->target, PClass::FindClass ("IceGuyFX"));
 	S_Sound (self, CHAN_WEAPON, self->AttackSound, 1, ATTN_NORM);
 }
 
@@ -129,7 +119,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_IceGuyMissileExplode)
 
 	for (i = 0; i < 8; i++)
 	{
-		mo = P_SpawnMissileAngleZ (self, self->z+3*FRACUNIT, 
+		mo = P_SpawnMissileAngleZ (self, self->Z()+3*FRACUNIT, 
 			PClass::FindClass("IceGuyFX2"), i*ANG45, (fixed_t)(-0.3*FRACUNIT));
 		if (mo)
 		{
diff --git a/src/g_hexen/a_korax.cpp b/src/g_hexen/a_korax.cpp
index a941f1a65e..fb833fdedc 100644
--- a/src/g_hexen/a_korax.cpp
+++ b/src/g_hexen/a_korax.cpp
@@ -97,7 +97,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_KoraxChase)
 		spot = iterator.Next ();
 		if (spot != NULL)
 		{
-			P_Teleport (self, spot->x, spot->y, ONFLOORZ, spot->angle, true, true, false);
+			P_Teleport (self, spot->X(), spot->Y(), ONFLOORZ, spot->angle, true, true, false);
 		}
 
 		P_StartScript (self, NULL, 249, NULL, NULL, 0, 0);
@@ -136,7 +136,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_KoraxChase)
 			self->tracer = spot;
 			if (spot)
 			{
-				P_Teleport (self, spot->x, spot->y, ONFLOORZ, spot->angle, true, true, false);
+				P_Teleport (self, spot->X(), spot->Y(), ONFLOORZ, spot->angle, true, true, false);
 			}
 		}
 	}
@@ -248,7 +248,6 @@ DEFINE_ACTION_FUNCTION(AActor, A_KoraxMissile)
 
 DEFINE_ACTION_FUNCTION(AActor, A_KoraxCommand)
 {
-	fixed_t x,y,z;
 	angle_t ang;
 	int numcommands;
 
@@ -256,10 +255,11 @@ DEFINE_ACTION_FUNCTION(AActor, A_KoraxCommand)
 
 	// Shoot stream of lightning to ceiling
 	ang = (self->angle - ANGLE_90) >> ANGLETOFINESHIFT;
-	x = self->x + KORAX_COMMAND_OFFSET * finecosine[ang];
-	y = self->y + KORAX_COMMAND_OFFSET * finesine[ang];
-	z = self->z + KORAX_COMMAND_HEIGHT*FRACUNIT;
-	Spawn("KoraxBolt", x, y, z, ALLOW_REPLACE);
+	fixedvec3 pos = self->Vec3Offset(
+		KORAX_COMMAND_OFFSET * finecosine[ang],
+		KORAX_COMMAND_OFFSET * finesine[ang],
+		KORAX_COMMAND_HEIGHT*FRACUNIT);
+	Spawn("KoraxBolt", pos, ALLOW_REPLACE);
 
 	if (self->health <= (self->SpawnHealth() >> 1))
 	{
@@ -310,14 +310,13 @@ void KoraxFire (AActor *actor, const PClass *type, int arm)
 	};
 
 	angle_t ang;
-	fixed_t x,y,z;
 
-	ang = (actor->angle + (arm < 3 ? -KORAX_DELTAANGLE : KORAX_DELTAANGLE))
-		>> ANGLETOFINESHIFT;
-	x = actor->x + extension[arm] * finecosine[ang];
-	y = actor->y + extension[arm] * finesine[ang];
-	z = actor->z - actor->floorclip + armheight[arm];
-	P_SpawnKoraxMissile (x, y, z, actor, actor->target, type);
+	ang = (actor->angle + (arm < 3 ? -KORAX_DELTAANGLE : KORAX_DELTAANGLE)) >> ANGLETOFINESHIFT;
+	fixedvec3 pos = actor->Vec3Offset(
+		extension[arm] * finecosine[ang],
+		extension[arm] * finesine[ang],
+		-actor->floorclip + armheight[arm]);
+	P_SpawnKoraxMissile (pos.x, pos.y, pos.z, actor, actor->target, type);
 }
 
 //============================================================================
@@ -372,11 +371,11 @@ void A_KSpiritSeeker (AActor *actor, angle_t thresh, angle_t turnMax)
 	actor->vely = FixedMul (actor->Speed, finesine[angle]);
 
 	if (!(level.time&15) 
-		|| actor->z > target->z+(target->GetDefault()->height)
-		|| actor->z+actor->height < target->z)
+		|| actor->Z() > target->Z()+(target->GetDefault()->height)
+		|| actor->Top() < target->Z())
 	{
-		newZ = target->z+((pr_kspiritseek()*target->GetDefault()->height)>>8);
-		deltaZ = newZ-actor->z;
+		newZ = target->Z()+((pr_kspiritseek()*target->GetDefault()->height)>>8);
+		deltaZ = newZ-actor->Z();
 		if (abs(deltaZ) > 15*FRACUNIT)
 		{
 			if(deltaZ > 0)
@@ -453,11 +452,11 @@ DEFINE_ACTION_FUNCTION(AActor, A_KBoltRaise)
 	fixed_t z;
 
 	// Spawn a child upward
-	z = self->z + KORAX_BOLT_HEIGHT;
+	z = self->Z() + KORAX_BOLT_HEIGHT;
 
 	if ((z + KORAX_BOLT_HEIGHT) < self->ceilingz)
 	{
-		mo = Spawn("KoraxBolt", self->x, self->y, z, ALLOW_REPLACE);
+		mo = Spawn("KoraxBolt", self->X(), self->Y(), z, ALLOW_REPLACE);
 		if (mo)
 		{
 			mo->special1 = KORAX_BOLT_LIFETIME;
@@ -499,6 +498,6 @@ AActor *P_SpawnKoraxMissile (fixed_t x, fixed_t y, fixed_t z,
 	{
 		dist = 1;
 	}
-	th->velz = (dest->z-z+(30*FRACUNIT))/dist;
+	th->velz = (dest->Z()-z+(30*FRACUNIT))/dist;
 	return (P_CheckMissileSpawn(th, source->radius) ? th : NULL);
 }
diff --git a/src/g_hexen/a_magecone.cpp b/src/g_hexen/a_magecone.cpp
index 6356fbb2ff..f9d98c78f6 100644
--- a/src/g_hexen/a_magecone.cpp
+++ b/src/g_hexen/a_magecone.cpp
@@ -120,7 +120,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ShedShard)
 	// every so many calls, spawn a new missile in its set directions
 	if (spawndir & SHARDSPAWN_LEFT)
 	{
-		mo = P_SpawnMissileAngleZSpeed (self, self->z, RUNTIME_CLASS(AFrostMissile), self->angle+(ANG45/9),
+		mo = P_SpawnMissileAngleZSpeed (self, self->Z(), RUNTIME_CLASS(AFrostMissile), self->angle+(ANG45/9),
 											 0, (20+2*spermcount)<<FRACBITS, self->target);
 		if (mo)
 		{
@@ -132,7 +132,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ShedShard)
 	}
 	if (spawndir & SHARDSPAWN_RIGHT)
 	{
-		mo = P_SpawnMissileAngleZSpeed (self, self->z, RUNTIME_CLASS(AFrostMissile), self->angle-(ANG45/9),
+		mo = P_SpawnMissileAngleZSpeed (self, self->Z(), RUNTIME_CLASS(AFrostMissile), self->angle-(ANG45/9),
 											 0, (20+2*spermcount)<<FRACBITS, self->target);
 		if (mo)
 		{
@@ -144,7 +144,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ShedShard)
 	}
 	if (spawndir & SHARDSPAWN_UP)
 	{
-		mo = P_SpawnMissileAngleZSpeed (self, self->z+8*FRACUNIT, RUNTIME_CLASS(AFrostMissile), self->angle, 
+		mo = P_SpawnMissileAngleZSpeed (self, self->Z()+8*FRACUNIT, RUNTIME_CLASS(AFrostMissile), self->angle, 
 											 0, (15+2*spermcount)<<FRACBITS, self->target);
 		if (mo)
 		{
@@ -159,7 +159,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ShedShard)
 	}
 	if (spawndir & SHARDSPAWN_DOWN)
 	{
-		mo = P_SpawnMissileAngleZSpeed (self, self->z-4*FRACUNIT, RUNTIME_CLASS(AFrostMissile), self->angle, 
+		mo = P_SpawnMissileAngleZSpeed (self, self->Z()-4*FRACUNIT, RUNTIME_CLASS(AFrostMissile), self->angle, 
 											 0, (15+2*spermcount)<<FRACBITS, self->target);
 		if (mo)
 		{
diff --git a/src/g_hexen/a_magelightning.cpp b/src/g_hexen/a_magelightning.cpp
index a13e3a2741..88c6dba8be 100644
--- a/src/g_hexen/a_magelightning.cpp
+++ b/src/g_hexen/a_magelightning.cpp
@@ -151,12 +151,12 @@ DEFINE_ACTION_FUNCTION(AActor, A_LightningClip)
 		{
 			return;
 		}
-		self->z = self->floorz;
+		self->SetZ(self->floorz);
 		target = self->lastenemy->tracer;
 	}
 	else if (self->flags3 & MF3_CEILINGHUGGER)
 	{
-		self->z = self->ceilingz-self->height;
+		self->SetZ(self->ceilingz-self->height);
 		target = self->tracer;
 	}
 	if (self->flags3 & MF3_FLOORHUGGER)
@@ -228,9 +228,11 @@ DEFINE_ACTION_FUNCTION(AActor, A_LightningZap)
 	{
 		deltaZ = -10*FRACUNIT;
 	}
-	mo = Spawn(lightning, self->x+((pr_zap()-128)*self->radius/256), 
-		self->y+((pr_zap()-128)*self->radius/256), 
-		self->z+deltaZ, ALLOW_REPLACE);
+	mo = Spawn(lightning,
+		self->Vec3Offset(
+			((pr_zap() - 128)*self->radius / 256),
+			((pr_zap() - 128)*self->radius / 256),
+			deltaZ), ALLOW_REPLACE);
 	if (mo)
 	{
 		mo->lastenemy = self;
@@ -329,7 +331,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_LastZap)
 
 	AActor *mo;
 
-	mo = Spawn(lightning, self->x, self->y, self->z, ALLOW_REPLACE);
+	mo = Spawn(lightning, self->Pos(), ALLOW_REPLACE);
 	if (mo)
 	{
 		mo->SetState (mo->FindState (NAME_Death));
diff --git a/src/g_hexen/a_magestaff.cpp b/src/g_hexen/a_magestaff.cpp
index 97a658a15d..4df037fc2c 100644
--- a/src/g_hexen/a_magestaff.cpp
+++ b/src/g_hexen/a_magestaff.cpp
@@ -140,8 +140,8 @@ DEFINE_ACTION_FUNCTION(AActor, A_MStaffAttack)
 	P_AimLineAttack (self, angle, PLAYERMISSILERANGE, &linetarget, ANGLE_1*32);
 	if (linetarget == NULL)
 	{
-		BlockCheckLine.x = self->x;
-		BlockCheckLine.y = self->y;
+		BlockCheckLine.x = self->X();
+		BlockCheckLine.y = self->Y();
 		BlockCheckLine.dx = -finesine[angle >> ANGLETOFINESHIFT];
 		BlockCheckLine.dy = -finecosine[angle >> ANGLETOFINESHIFT];
 		linetarget = P_BlockmapSearch (self, 10, FrontBlockCheck);
@@ -202,7 +202,7 @@ static AActor *FrontBlockCheck (AActor *mo, int index, void *)
 	{
 		if (link->Me != mo)
 		{
-			if (P_PointOnDivlineSide (link->Me->x, link->Me->y, &BlockCheckLine) == 0 &&
+			if (P_PointOnDivlineSide (link->Me->X(), link->Me->Y(), &BlockCheckLine) == 0 &&
 				mo->IsOkayToAttack (link->Me))
 			{
 				return link->Me;
@@ -222,7 +222,7 @@ void MStaffSpawn2 (AActor *actor, angle_t angle)
 {
 	AActor *mo;
 
-	mo = P_SpawnMissileAngleZ (actor, actor->z+40*FRACUNIT,
+	mo = P_SpawnMissileAngleZ (actor, actor->Z()+40*FRACUNIT,
 		RUNTIME_CLASS(AMageStaffFX2), angle, 0);
 	if (mo)
 	{
diff --git a/src/g_hexen/a_pig.cpp b/src/g_hexen/a_pig.cpp
index 437a336a38..21d141b0cd 100644
--- a/src/g_hexen/a_pig.cpp
+++ b/src/g_hexen/a_pig.cpp
@@ -96,7 +96,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_SnoutAttack)
 DEFINE_ACTION_FUNCTION(AActor, A_PigPain)
 {
 	CALL_ACTION(A_Pain, self);
-	if (self->z <= self->floorz)
+	if (self->Z() <= self->floorz)
 	{
 		self->velz = FRACUNIT*7/2;
 	}
diff --git a/src/g_hexen/a_serpent.cpp b/src/g_hexen/a_serpent.cpp
index cf552897fe..39b4382e30 100644
--- a/src/g_hexen/a_serpent.cpp
+++ b/src/g_hexen/a_serpent.cpp
@@ -202,9 +202,11 @@ DEFINE_ACTION_FUNCTION(AActor, A_SerpentSpawnGibs)
 
 	for (int i = countof(GibTypes)-1; i >= 0; --i)
 	{
-		mo = Spawn (GibTypes[i],
-			self->x+((pr_serpentgibs()-128)<<12), 
-			self->y+((pr_serpentgibs()-128)<<12),
+		fixedvec2 pos = self->Vec2Offset(
+			((pr_serpentgibs() - 128) << 12),
+			((pr_serpentgibs() - 128) << 12));
+
+		mo = Spawn (GibTypes[i], pos.x, pos.y,
 			self->floorz+FRACUNIT, ALLOW_REPLACE);
 		if (mo)
 		{
@@ -256,7 +258,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_DelayGib)
 
 DEFINE_ACTION_FUNCTION(AActor, A_SerpentHeadCheck)
 {
-	if (self->z <= self->floorz)
+	if (self->Z() <= self->floorz)
 	{
 		if (Terrains[P_GetThingFloorType(self)].IsLiquid)
 		{
diff --git a/src/g_hexen/a_spike.cpp b/src/g_hexen/a_spike.cpp
index 9c9f9ab204..90729a77db 100644
--- a/src/g_hexen/a_spike.cpp
+++ b/src/g_hexen/a_spike.cpp
@@ -95,7 +95,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ThrustInitDn)
 	self->flags2 = MF2_NOTELEPORT|MF2_FLOORCLIP;
 	self->renderflags = RF_INVISIBLE;
 	static_cast<AThrustFloor *>(self)->DirtClump =
-		Spawn("DirtClump", self->x, self->y, self->z, ALLOW_REPLACE);
+		Spawn("DirtClump", self->Pos(), ALLOW_REPLACE);
 }
 
 
@@ -140,7 +140,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_ThrustLower)
 DEFINE_ACTION_FUNCTION(AActor, A_ThrustImpale)
 {
 	AActor *thing;
-	FBlockThingsIterator it(FBoundingBox(self->x, self->y, self->radius));
+	FBlockThingsIterator it(FBoundingBox(self->X(), self->Y(), self->radius));
 	while ((thing = it.Next()))
 	{
 		if (!thing->intersects(self))
diff --git a/src/g_hexen/a_summon.cpp b/src/g_hexen/a_summon.cpp
index cbb8a38542..0fffb6e4ce 100644
--- a/src/g_hexen/a_summon.cpp
+++ b/src/g_hexen/a_summon.cpp
@@ -51,13 +51,13 @@ DEFINE_ACTION_FUNCTION(AActor, A_Summon)
 {
 	AMinotaurFriend *mo;
 
-	mo = Spawn<AMinotaurFriend> (self->x, self->y, self->z, ALLOW_REPLACE);
+	mo = Spawn<AMinotaurFriend> (self->Pos(), ALLOW_REPLACE);
 	if (mo)
 	{
 		if (P_TestMobjLocation(mo) == false || !self->tracer)
 		{ // Didn't fit - change back to artifact
 			mo->Destroy ();
-			AActor *arti = Spawn<AArtiDarkServant> (self->x, self->y, self->z, ALLOW_REPLACE);
+			AActor *arti = Spawn<AArtiDarkServant> (self->Pos(), ALLOW_REPLACE);
 			if (arti) arti->flags |= MF_DROPPED;
 			return;
 		}
@@ -76,7 +76,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_Summon)
 		}
 
 		// Make smoke puff
-		Spawn ("MinotaurSmoke", self->x, self->y, self->z, ALLOW_REPLACE);
+		Spawn ("MinotaurSmoke", self->Pos(), ALLOW_REPLACE);
 		S_Sound (self, CHAN_VOICE, mo->ActiveSound, 1, ATTN_NORM);
 	}
 }
diff --git a/src/g_hexen/a_teleportother.cpp b/src/g_hexen/a_teleportother.cpp
index 2bf99640b5..14edd75197 100644
--- a/src/g_hexen/a_teleportother.cpp
+++ b/src/g_hexen/a_teleportother.cpp
@@ -51,7 +51,7 @@ static void TeloSpawn (AActor *source, const char *type)
 {
 	AActor *fx;
 
-	fx = Spawn (type, source->x, source->y, source->z, ALLOW_REPLACE);
+	fx = Spawn (type, source->Pos(), ALLOW_REPLACE);
 	if (fx)
 	{
 		fx->special1 = TELEPORT_LIFE;			// Lifetime countdown
diff --git a/src/g_hexen/a_wraith.cpp b/src/g_hexen/a_wraith.cpp
index b339f14be2..312585cdfb 100644
--- a/src/g_hexen/a_wraith.cpp
+++ b/src/g_hexen/a_wraith.cpp
@@ -29,12 +29,12 @@ static FRandom pr_wraithfx4 ("WraithFX4");
 
 DEFINE_ACTION_FUNCTION(AActor, A_WraithInit)
 {
-	self->z += 48<<FRACBITS;
+	self->AddZ(48<<FRACBITS);
 
 	// [RH] Make sure the wraith didn't go into the ceiling
-	if (self->z + self->height > self->ceilingz)
+	if (self->Top() > self->ceilingz)
 	{
-		self->z = self->ceilingz - self->height;
+		self->SetZ(self->ceilingz - self->height);
 	}
 
 	self->special1 = 0;			// index into floatbob
@@ -110,7 +110,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_WraithFX2)
 
 	for (i = 2; i; --i)
 	{
-		mo = Spawn ("WraithFX2", self->x, self->y, self->z, ALLOW_REPLACE);
+		mo = Spawn ("WraithFX2", self->Pos(), ALLOW_REPLACE);
 		if(mo)
 		{
 			if (pr_wraithfx2 ()<128)
@@ -147,12 +147,16 @@ DEFINE_ACTION_FUNCTION(AActor, A_WraithFX3)
 
 	while (numdropped-- > 0)
 	{
-		mo = Spawn ("WraithFX3", self->x, self->y, self->z, ALLOW_REPLACE);
+		fixedvec3 pos = self->Vec3Offset(
+			(pr_wraithfx3()-128)<<11,
+			(pr_wraithfx3()-128)<<11,
+			(pr_wraithfx3()<<10));
+
+		mo = Spawn ("WraithFX3", pos, ALLOW_REPLACE);
 		if (mo)
 		{
-			mo->x += (pr_wraithfx3()-128)<<11;
-			mo->y += (pr_wraithfx3()-128)<<11;
-			mo->z += (pr_wraithfx3()<<10);
+			mo->floorz = self->floorz;
+			mo->ceilingz = self->ceilingz;
 			mo->target = self;
 		}
 	}
@@ -195,23 +199,31 @@ void A_WraithFX4 (AActor *self)
 
 	if (spawn4)
 	{
-		mo = Spawn ("WraithFX4", self->x, self->y, self->z, ALLOW_REPLACE);
+		fixedvec3 pos = self->Vec3Offset(
+			(pr_wraithfx4()-128)<<12,
+			(pr_wraithfx4()-128)<<12,
+			(pr_wraithfx4()<<10));
+
+		mo = Spawn ("WraithFX4", pos, ALLOW_REPLACE);
 		if (mo)
 		{
-			mo->x += (pr_wraithfx4()-128)<<12;
-			mo->y += (pr_wraithfx4()-128)<<12;
-			mo->z += (pr_wraithfx4()<<10);
+			mo->floorz = self->floorz;
+			mo->ceilingz = self->ceilingz;
 			mo->target = self;
 		}
 	}
 	if (spawn5)
 	{
-		mo = Spawn ("WraithFX5", self->x, self->y, self->z, ALLOW_REPLACE);
+		fixedvec3 pos = self->Vec3Offset(
+			(pr_wraithfx4()-128)<<12,
+			(pr_wraithfx4()-128)<<12,
+			(pr_wraithfx4()<<10));
+
+		mo = Spawn ("WraithFX5", pos, ALLOW_REPLACE);
 		if (mo)
 		{
-			mo->x += (pr_wraithfx4()-128)<<11;
-			mo->y += (pr_wraithfx4()-128)<<11;
-			mo->z += (pr_wraithfx4()<<10);
+			mo->floorz = self->floorz;
+			mo->ceilingz = self->ceilingz;
 			mo->target = self;
 		}
 	}
@@ -226,7 +238,7 @@ void A_WraithFX4 (AActor *self)
 DEFINE_ACTION_FUNCTION(AActor, A_WraithChase)
 {
 	int weaveindex = self->special1;
-	self->z += finesine[weaveindex << BOBTOFINESHIFT] * 8;
+	self->AddZ(finesine[weaveindex << BOBTOFINESHIFT] * 8);
 	self->special1 = (weaveindex + 2) & 63;
 //	if (self->floorclip > 0)
 //	{
diff --git a/src/g_raven/a_minotaur.cpp b/src/g_raven/a_minotaur.cpp
index c2348a9e3a..bf795fb331 100644
--- a/src/g_raven/a_minotaur.cpp
+++ b/src/g_raven/a_minotaur.cpp
@@ -186,8 +186,8 @@ DEFINE_ACTION_FUNCTION(AActor, A_MinotaurDecide)
 		S_Sound (self, CHAN_WEAPON, "minotaur/sight", 1, ATTN_NORM);
 	}
 	dist = self->AproxDistance (target);
-	if (target->z+target->height > self->z
-		&& target->z+target->height < self->z+self->height
+	if (target->Top() > self->Z()
+		&& target->Top() < self->Top()
 		&& dist < (friendly ? 16*64*FRACUNIT : 8*64*FRACUNIT)
 		&& dist > 1*64*FRACUNIT
 		&& pr_minotaurdecide() < 150)
@@ -205,7 +205,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_MinotaurDecide)
 		self->vely = FixedMul (MNTR_CHARGE_SPEED, finesine[angle]);
 		self->special1 = TICRATE/2; // Charge duration
 	}
-	else if (target->z == target->floorz
+	else if (target->Z() == target->floorz
 		&& dist < 9*64*FRACUNIT
 		&& pr_minotaurdecide() < (friendly ? 100 : 220))
 	{ // Floor fire attack
@@ -244,7 +244,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_MinotaurCharge)
 		{
 			type = PClass::FindClass ("PunchPuff");
 		}
-		puff = Spawn (type, self->x, self->y, self->z, ALLOW_REPLACE);
+		puff = Spawn (type, self->Pos(), ALLOW_REPLACE);
 		puff->velz = 2*FRACUNIT;
 		self->special1--;
 	}
@@ -285,7 +285,7 @@ DEFINE_ACTION_FUNCTION(AActor, A_MinotaurAtk2)
 		P_TraceBleed (newdam > 0 ? newdam : damage, self->target, self);
 		return;
 	}
-	z = self->z + 40*FRACUNIT;
+	z = self->Z() + 40*FRACUNIT;
 	const PClass *fx = PClass::FindClass("MinotaurFX1");
 	if (fx)
 	{
@@ -369,10 +369,11 @@ DEFINE_ACTION_FUNCTION(AActor, A_MntrFloorFire)
 	AActor *mo;
 	fixed_t x, y;
 
-	self->z = self->floorz;
-	x = self->x + (pr_fire.Random2 () << 10);
-	y = self->y + (pr_fire.Random2 () << 10);
-	mo = Spawn("MinotaurFX3", x, y, self->floorz, ALLOW_REPLACE);
+	self->SetZ(self->floorz);
+	fixedvec2 pos = self->Vec2Offset(
+		(pr_fire.Random2 () << 10),
+		(pr_fire.Random2 () << 10));
+	mo = Spawn("MinotaurFX3", pos.x, pos.y, self->floorz, ALLOW_REPLACE);
 	mo->target = self->target;
 	mo->velx = 1; // Force block checking
 	P_CheckMissileSpawn (mo, self->radius);
diff --git a/src/p_local.h b/src/p_local.h
index 8c4a94bfc3..4e2172a525 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -148,6 +148,10 @@ void	P_ExplodeMissile (AActor *missile, line_t *explodeline, AActor *target);
 AActor *P_SpawnMissile (AActor* source, AActor* dest, const PClass *type, AActor* owner = NULL);
 AActor *P_SpawnMissileZ (AActor* source, fixed_t z, AActor* dest, const PClass *type);
 AActor *P_SpawnMissileXYZ (fixed_t x, fixed_t y, fixed_t z, AActor *source, AActor *dest, const PClass *type, bool checkspawn = true, AActor *owner = NULL);
+inline AActor *P_SpawnMissileXYZ(const fixedvec3 &pos, AActor *source, AActor *dest, const PClass *type, bool checkspawn = true, AActor *owner = NULL)
+{
+	return P_SpawnMissileXYZ(pos.x, pos.y, pos.z, source, dest, type, checkspawn, owner);
+}
 AActor *P_SpawnMissileAngle (AActor *source, const PClass *type, angle_t angle, fixed_t velz);
 AActor *P_SpawnMissileAngleSpeed (AActor *source, const PClass *type, angle_t angle, fixed_t velz, fixed_t speed);
 AActor *P_SpawnMissileAngleZ (AActor *source, fixed_t z, const PClass *type, angle_t angle, fixed_t velz);