diff --git a/src/engine/db/handlers/dbBuildingHandler.java b/src/engine/db/handlers/dbBuildingHandler.java
index 4f68e9e2..ae4ac9f5 100644
--- a/src/engine/db/handlers/dbBuildingHandler.java
+++ b/src/engine/db/handlers/dbBuildingHandler.java
@@ -64,8 +64,8 @@ public class dbBuildingHandler extends dbHandlerBase {
                 preparedStatement.setNull(13, java.sql.Types.DATE);
 
             preparedStatement.setInt(14, building.getBlueprintUUID());
-            preparedStatement.setFloat(15, building.getw());
-            preparedStatement.setFloat(16, building.getRot().y);
+            preparedStatement.setFloat(15, building.getRotation().w);
+            preparedStatement.setFloat(16, building.getRotation().y);
 
             ResultSet rs = preparedStatement.executeQuery();
 
diff --git a/src/engine/devcmd/cmds/AddBuildingCmd.java b/src/engine/devcmd/cmds/AddBuildingCmd.java
index cb73b091..186f1f73 100644
--- a/src/engine/devcmd/cmds/AddBuildingCmd.java
+++ b/src/engine/devcmd/cmds/AddBuildingCmd.java
@@ -14,7 +14,7 @@ import engine.devcmd.AbstractDevCmd;
 import engine.gameManager.ChatManager;
 import engine.gameManager.DbManager;
 import engine.gameManager.ZoneManager;
-import engine.math.Vector3f;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums.ProtectionState;
 import engine.objects.*;
@@ -54,8 +54,7 @@ public class AddBuildingCmd extends AbstractDevCmd {
                     "Invalid addBuilding Command. Invalid Building ID.");
             return;
         }
-        Vector3f rot = new Vector3f(0.0f, 0.0f, 0.0f);
-        float w = 1f;
+        Quaternion rotation = new Quaternion();
         Zone zone = ZoneManager.findSmallestZone(pc.getLoc());
 
         if (zone == null) {
@@ -73,8 +72,7 @@ public class AddBuildingCmd extends AbstractDevCmd {
         Building likeBuilding = DbManager.BuildingQueries.GET_BUILDING_BY_MESH(ID);
 
         if (likeBuilding != null) {
-            rot = likeBuilding.getRot();
-            w = likeBuilding.getw();
+            rotation = likeBuilding.getRotation();
         }
 
         String buildingName = "";
@@ -93,7 +91,7 @@ public class AddBuildingCmd extends AbstractDevCmd {
         Building building = Building.persistBuilding(Building.createBuilding(
                 zone, 0, buildingName, ID,
                 localLoc, 1.0f, 0, ProtectionState.PROTECTED, 0, rank,
-                null, blueprintUUID, w, rot.y));
+                null, blueprintUUID, rotation.w, rotation.y));
 
 
         if (building == null) {
@@ -101,9 +99,6 @@ public class AddBuildingCmd extends AbstractDevCmd {
             return;
         }
 
-        building.setRot(rot);
-        building.setw(w);
-
         building.setObjectTypeMask(MBServerStatics.MASK_BUILDING);
         WorldGrid.addObject(building, pc);
         ChatManager.chatSayInfo(pc,
diff --git a/src/engine/devcmd/cmds/InfoCmd.java b/src/engine/devcmd/cmds/InfoCmd.java
index 3ca9059c..b4c6891c 100644
--- a/src/engine/devcmd/cmds/InfoCmd.java
+++ b/src/engine/devcmd/cmds/InfoCmd.java
@@ -88,7 +88,7 @@ public class InfoCmd extends AbstractDevCmd {
             output += newline;
             output += StringUtils.addWS("Alt: " + targetLoc.y, 20);
             output += newline;
-            output += "Rot: " + targetAWO.getRot().y;
+            output += "Rot: " + targetAWO.getRotation().y;
             output += newline;
             double radian = 0;
 
@@ -106,7 +106,7 @@ public class InfoCmd extends AbstractDevCmd {
             case Building:
                 Building targetBuilding = (Building) target;
                 output += StringUtils.addWS("Lac: "
-                        + targetBuilding.getw(), 20);
+                        + targetBuilding.getRotation().w, 20);
                 output += "Blueprint : ";
                 output += targetBuilding.getBlueprintUUID();
                 output += newline;
diff --git a/src/engine/devcmd/cmds/RotateCmd.java b/src/engine/devcmd/cmds/RotateCmd.java
index 1beb1f52..fc8b22c6 100644
--- a/src/engine/devcmd/cmds/RotateCmd.java
+++ b/src/engine/devcmd/cmds/RotateCmd.java
@@ -14,7 +14,7 @@ import engine.devcmd.AbstractDevCmd;
 import engine.gameManager.BuildingManager;
 import engine.gameManager.ChatManager;
 import engine.gameManager.DbManager;
-import engine.math.Vector3f;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.objects.*;
 
@@ -63,14 +63,12 @@ public class RotateCmd extends AbstractDevCmd {
                 return;
             }
 
-            Vector3f rotation = new Vector3f(0f, rot, 0f);
-
             if (target instanceof Building)
-                rotateBuilding(pc, (Building) target, rotation, rot, false);
+                rotateBuilding(pc, (Building) target, rot);
             else if (target instanceof NPC)
-                rotateNPC(pc, (NPC) target, rotation, false);
+                rotateNPC(pc, (NPC) target, rot);
             else if (target instanceof Mob)
-                rotateMob(pc, (Mob) target, rotation, false);
+                rotateMob(pc, (Mob) target, rot);
             else
                 throwbackError(pc, "Target " + target.getObjectType()
                         + " is not a valid object type");
@@ -141,15 +139,13 @@ public class RotateCmd extends AbstractDevCmd {
                 }
             }
 
-            Vector3f rotation = new Vector3f(0f, rot, 0f);
-
             Building b;
             if (id != 0)
                 b = BuildingManager.getBuilding(id);
             else
                 b = getTargetAsBuilding(pc);
             if (b != null) {
-                rotateBuilding(pc, b, rotation, rot, false);
+                rotateBuilding(pc, b, rot);
                 return;
             }
 
@@ -160,7 +156,7 @@ public class RotateCmd extends AbstractDevCmd {
             else
                 npc = getTargetAsNPC(pc);
             if (npc != null) {
-                rotateNPC(pc, npc, rotation, false);
+                rotateNPC(pc, npc, rot);
                 return;
             }
 
@@ -171,7 +167,7 @@ public class RotateCmd extends AbstractDevCmd {
             else
                 mob = getTargetAsMob(pc);
             if (mob != null) {
-                rotateMob(pc, mob, rotation, false);
+                rotateMob(pc, mob, rot);
                 return;
             }
             throwbackError(pc, "Nothing found to rotate.");
@@ -188,31 +184,29 @@ public class RotateCmd extends AbstractDevCmd {
         return "' /rotate [objectID] rotation' || ' /rot [objectID] rotation'";
     }
 
-    private void rotateBuilding(PlayerCharacter pc, Building building, Vector3f rot, float orig, boolean faceDirection) {
-        if (!faceDirection)
-            rot.set(0.0f, (float) Math.sin(Math.toRadians(orig) / 2), 0.0f);
-        building.setRot(rot);
-        building.setw((float) Math.abs(Math.cos(Math.toRadians(orig) / 2)));
+    private void rotateBuilding(PlayerCharacter pc, Building building, float orig) {
+        building.setRotation(new Quaternion(0f, (float) Math.sin(Math.toRadians(orig) / 2), 0f,
+                (float) Math.abs(Math.cos(Math.toRadians(orig) / 2))));
         building.getBounds().setBounds(building);
         WorldGrid.updateObject(building, pc);
-        DbManager.BuildingQueries.SET_PROPERTY(building, "rotY", building.getRot().getY());
-        DbManager.BuildingQueries.SET_PROPERTY(building, "w", building.getw());
+        DbManager.BuildingQueries.SET_PROPERTY(building, "rotY", building.getRotation().y);
+        DbManager.BuildingQueries.SET_PROPERTY(building, "w", building.getRotation().w);
         ChatManager.chatSayInfo(pc,
                 "Building with ID " + building.getObjectUUID() + " rotated");
     }
 
-    private void rotateNPC(PlayerCharacter pc, NPC npc, Vector3f rot, boolean faceDirection) {
-        npc.setRot(rot);
-        DbManager.NPCQueries.SET_PROPERTY(npc, "npc_rotation", rot.y);
+    private void rotateNPC(PlayerCharacter pc, NPC npc, float rot) {
+        npc.setRotation(Quaternion.fromYaw((float) Math.acos(rot) * 2));
+        DbManager.NPCQueries.SET_PROPERTY(npc, "npc_rotation", rot);
         WorldGrid.updateObject(npc, pc);
         //no rotation for npc's in db currently
         ChatManager.chatSayInfo(pc,
                 "NPC with ID " + npc.getObjectUUID() + " rotated");
     }
 
-    private void rotateMob(PlayerCharacter pc, Mob mob, Vector3f rot, boolean faceDirection) {
-        mob.setRot(rot);
-        DbManager.MobQueries.SET_PROPERTY(mob, "mob_rotation", rot.y);
+    private void rotateMob(PlayerCharacter pc, Mob mob, float rot) {
+        mob.setRotation(Quaternion.fromYaw((float) Math.acos(rot) * 2));
+        DbManager.MobQueries.SET_PROPERTY(mob, "mob_rotation", rot);
         WorldGrid.updateObject(mob, pc);
         //no rotation for mobs's in db currently
         ChatManager.chatSayInfo(pc,
@@ -235,14 +229,12 @@ public class RotateCmd extends AbstractDevCmd {
         if (rot > 180)
             rot *= -1;
 
-        Vector3f buildingrotation = new Vector3f(0f, rot, 0f);
-        Vector3f rotation = new Vector3f(0f, rotangle, 0f);
         if (target instanceof Building)
-            rotateBuilding(pc, (Building) target, buildingrotation, rot, false);
+            rotateBuilding(pc, (Building) target, rot);
         else if (target instanceof NPC)
-            rotateNPC(pc, (NPC) target, rotation, true);
+            rotateNPC(pc, (NPC) target, rotangle);
         else if (target instanceof Mob)
-            rotateMob(pc, (Mob) target, rotation, true);
+            rotateMob(pc, (Mob) target, rotangle);
         else
             throwbackError(pc, "Target " + target.getObjectType()
                     + " is not a valid object type");
diff --git a/src/engine/gameManager/NPCManager.java b/src/engine/gameManager/NPCManager.java
index 3a535e75..0c253729 100644
--- a/src/engine/gameManager/NPCManager.java
+++ b/src/engine/gameManager/NPCManager.java
@@ -11,7 +11,6 @@ package engine.gameManager;
 import engine.InterestManagement.WorldGrid;
 import engine.loot.WorkOrder;
 import engine.math.Quaternion;
-import engine.math.Vector3f;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums;
 import engine.net.Dispatch;
@@ -32,8 +31,6 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 
-import static engine.math.FastMath.acos;
-
 public enum NPCManager {
 
     NPC_MANAGER;
@@ -227,11 +224,12 @@ public enum NPCManager {
 
         abstractCharacter.loc = new Vector3fImmutable(abstractCharacter.bindLoc);
 
-        // Rotate NPC rotation by the building's rotation
+        // Rotate NPC rotation by the building's rotation.
+        // Kept for wire parity: the product's sin θ/2 is read back as cos θ/2, so the yaw sent is not own + building.
 
-        Quaternion slotRotation = new Quaternion().fromAngles(0, acos(abstractCharacter.getRot().y) * 2, 0);
+        Quaternion slotRotation = new Quaternion().fromAngles(0, abstractCharacter.getRotation().getYaw(), 0);
         slotRotation = slotRotation.mult(abstractCharacter.building.getBounds().getQuaternion());
-        abstractCharacter.setRot(new Vector3f(0, slotRotation.y, 0));
+        abstractCharacter.setRotation(Quaternion.fromYaw((float) Math.acos(slotRotation.y) * 2));
 
         // Configure region and floor/level for this NPC
 
diff --git a/src/engine/math/Bounds.java b/src/engine/math/Bounds.java
index 8cb237c1..46d1ddf3 100644
--- a/src/engine/math/Bounds.java
+++ b/src/engine/math/Bounds.java
@@ -408,7 +408,7 @@ public class Bounds {
 
         blueprint = building.getBlueprint();
 
-        this.quaternion = new Quaternion(building.getRot().x, building.getRot().y, building.getRot().z, building.getw());
+        this.quaternion = new Quaternion(building.getRotation().x, building.getRotation().y, building.getRotation().z, building.getRotation().w);
 
         // Calculate Bounds for non-blueprint objects
 
@@ -437,7 +437,7 @@ public class Bounds {
 
             // The rotation is reset after the new aabb is calculated.
 
-            this.rotation = building.getRot().y;
+            this.rotation = building.getRotation().y;
 
             // Caclculate and set the new half halfExtents for the rotated bounding box
             // and reset the rotation to 0 for this bounds.
@@ -451,7 +451,7 @@ public class Bounds {
         }
 
         this.origin.set(building.getLoc().x, building.getLoc().z);
-        this.rotation = building.getRot().y;
+        this.rotation = building.getRotation().y;
         this.halfExtents.set(blueprint.getExtents());
         this.flipExtents = Bounds.calculateFlipExtents(this);
 
diff --git a/src/engine/objects/AbstractCharacter.java b/src/engine/objects/AbstractCharacter.java
index f4037d52..27e45e59 100644
--- a/src/engine/objects/AbstractCharacter.java
+++ b/src/engine/objects/AbstractCharacter.java
@@ -21,6 +21,7 @@ import engine.jobs.PersistentAoeJob;
 import engine.jobs.TrackJob;
 import engine.math.AtomicFloat;
 import engine.math.Bounds;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums;
 import engine.mbEnums.*;
@@ -536,6 +537,18 @@ public abstract class AbstractCharacter extends AbstractWorldObject {
 
     }
 
+    // The one yaw float LOADCHARACTER carries; a character in a building gets the building's yaw added.
+    public float getClientYaw() {
+
+        float yaw = this.getRotation().getYaw();
+
+        if (this.building != null)
+            if (this.building.getBounds() != null && this.building.getBounds().getQuaternion() != null)
+                yaw += this.building.getBounds().getQuaternion().angleY;
+
+        return yaw;
+    }
+
     public static void teleport(AbstractCharacter abstractCharacter, final Vector3fImmutable targetLoc) {
         abstractCharacter.locationLock.writeLock().lock();
         try {
diff --git a/src/engine/objects/AbstractWorldObject.java b/src/engine/objects/AbstractWorldObject.java
index dd5c691f..74fb02cc 100644
--- a/src/engine/objects/AbstractWorldObject.java
+++ b/src/engine/objects/AbstractWorldObject.java
@@ -18,7 +18,7 @@ import engine.job.JobScheduler;
 import engine.jobs.NoTimeJob;
 import engine.math.AtomicFloat;
 import engine.math.Bounds;
-import engine.math.Vector3f;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums.DispatchChannel;
 import engine.mbEnums.EffectSourceType;
@@ -56,7 +56,7 @@ public abstract class AbstractWorldObject extends AbstractGameObject {
     protected boolean movingUp = false;
     private String name = "";
     private byte tier = 0;
-    private Vector3f rot = new Vector3f(0.0f, 0.0f, 0.0f);
+    private Quaternion rotation = new Quaternion();
     private int objectTypeMask = 0;
     private Bounds bounds;
 
@@ -528,13 +528,13 @@ public abstract class AbstractWorldObject extends AbstractGameObject {
 
     }
 
-    public Vector3f getRot() {
-        return rot;
+    public Quaternion getRotation() {
+        return rotation;
     }
 
-    public void setRot(Vector3f rotation) {
-        synchronized (this.rot) {
-            this.rot = rotation;
+    public void setRotation(Quaternion rotation) {
+        synchronized (this.rotation) {
+            this.rotation = rotation;
         }
     }
 
@@ -543,7 +543,7 @@ public abstract class AbstractWorldObject extends AbstractGameObject {
     }
 
     public void setTier(byte tier) {
-        synchronized (this.rot) {
+        synchronized (this.rotation) {
             this.tier = tier;
         }
     }
diff --git a/src/engine/objects/Building.java b/src/engine/objects/Building.java
index 15a06fe9..66245a0b 100644
--- a/src/engine/objects/Building.java
+++ b/src/engine/objects/Building.java
@@ -24,6 +24,7 @@ import engine.job.JobScheduler;
 import engine.jobs.DoorCloseJob;
 import engine.jobs.SiegeSpireWithdrawlJob;
 import engine.math.Bounds;
+import engine.math.Quaternion;
 import engine.math.Vector3f;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums;
@@ -85,7 +86,6 @@ public class Building extends AbstractWorldObject {
     public ArrayList<Vector3fImmutable> patrolPoints;
     public ProtectionState protectionState = ProtectionState.NONE;
     protected Resists resists;
-    private float w = 1.0f;
     private Vector3f meshScale = new Vector3f(1.0f, 1.0f, 1.0f);
     private int doorState = 0;
     private int ownerUUID = 0;  //NPC or Character--check ownerIsNPC flag
@@ -128,8 +128,7 @@ public class Building extends AbstractWorldObject {
             this.ownerUUID = rs.getInt("ownerUUID");
             this.doorState = rs.getInt("doorState");
             this.setHealth(rs.getInt("currentHP"));
-            this.w = rs.getFloat("w");
-            this.setRot(new Vector3f(0f, rs.getFloat("rotY"), 0f));
+            this.setRotation(new Quaternion(0f, rs.getFloat("rotY"), 0f, rs.getFloat("w")));
             this.reverseKOS = rs.getByte("reverseKOS") == 1;
             this.statLat = rs.getFloat("locationX");
             this.statAlt = rs.getFloat("locationY");
@@ -207,8 +206,7 @@ public class Building extends AbstractWorldObject {
         building._strongboxValue = currentGold;
         building.maxGold = 15000000;
         building.rank = rank;
-        building.w = w;
-        building.setRot(new Vector3f(0f, rotY, 0f));
+        building.setRotation(new Quaternion(0f, rotY, 0f, w));
         building.parentBuildingID = 0;
         building.floor = -1;
         building.level = -1;
@@ -261,11 +259,11 @@ public class Building extends AbstractWorldObject {
             writer.putFloat(building.getLoc().getZ());
         }
 
-        writer.putFloat(building.w);
-        writer.putFloat(0f);
-        writer.putFloat(building.getRot().y);
+        writer.putFloat(building.getRotation().w);
+        writer.putFloat(building.getRotation().x);
+        writer.putFloat(building.getRotation().y);
+        writer.putFloat(building.getRotation().z);
 
-        writer.putFloat(0f);
         writer.putFloat(building.meshScale.getX());
         writer.putFloat(building.meshScale.getY());
         writer.putFloat(building.meshScale.getZ());
@@ -752,14 +750,6 @@ public class Building extends AbstractWorldObject {
         this.healthMax = maxHealth;
     }
 
-    public final void setw(float value) {
-        this.w = value;
-    }
-
-    public final float getw() {
-        return this.w;
-    }
-
     public final Vector3f getMeshScale() {
         return this.meshScale;
     }
diff --git a/src/engine/objects/Mob.java b/src/engine/objects/Mob.java
index 9491b71a..c83c0acd 100644
--- a/src/engine/objects/Mob.java
+++ b/src/engine/objects/Mob.java
@@ -15,6 +15,8 @@ import engine.job.JobScheduler;
 import engine.jobs.DeferredPowerJob;
 import engine.jobs.UpgradeNPCJob;
 import engine.math.Bounds;
+import engine.math.FastMath;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums;
 import engine.mbEnums.*;
@@ -80,6 +82,7 @@ public class Mob extends AbstractIntelligenceAgent implements Delayed {
     // PERSIST.
     public Mob() {
         super();
+        this.setRotation(Quaternion.fromYaw(FastMath.PI));
         this.dbID = MBServerStatics.NO_DB_ROW_ASSIGNED_YET;
         this.currentID = MBServerStatics.NO_DB_ROW_ASSIGNED_YET;
         this.bindLoc = Vector3fImmutable.ZERO;
@@ -99,6 +102,9 @@ public class Mob extends AbstractIntelligenceAgent implements Delayed {
         float statAlt;
         float statLon;
 
+        // mob_rotation is not loaded: the old default (cos θ/2 = 0) faced every mob at yaw π.
+        this.setRotation(Quaternion.fromYaw(FastMath.PI));
+
         try {
             this.dbID = rs.getInt(1);
             this.loadID = rs.getInt("mob_mobbaseID");
@@ -240,14 +246,7 @@ public class Mob extends AbstractIntelligenceAgent implements Delayed {
 
         writer.putVector3f(mob.getLoc());
 
-        //Rotation
-        float radians = (float) Math.acos(mob.getRot().y) * 2;
-
-        if (mob.building != null)
-            if (mob.building.getBounds() != null && mob.building.getBounds().getQuaternion() != null)
-                radians += (mob.building.getBounds().getQuaternion()).angleY;
-
-        writer.putFloat(radians);
+        writer.putFloat(mob.getClientYaw());
 
         //Inventory Stuff
 
diff --git a/src/engine/objects/NPC.java b/src/engine/objects/NPC.java
index fba8beb2..a95582d5 100644
--- a/src/engine/objects/NPC.java
+++ b/src/engine/objects/NPC.java
@@ -15,7 +15,8 @@ import engine.job.JobContainer;
 import engine.job.JobScheduler;
 import engine.jobs.UpgradeNPCJob;
 import engine.math.Bounds;
-import engine.math.Vector3f;
+import engine.math.FastMath;
+import engine.math.Quaternion;
 import engine.math.Vector3fImmutable;
 import engine.mbEnums;
 import engine.mbEnums.*;
@@ -80,6 +81,7 @@ public class NPC extends AbstractCharacter {
     public NPC() {
 
         super();
+        this.setRotation(Quaternion.fromYaw(FastMath.PI));
         this.dbID = MBServerStatics.NO_DB_ROW_ASSIGNED_YET;
         this.currentID = MBServerStatics.NO_DB_ROW_ASSIGNED_YET;
     }
@@ -118,7 +120,8 @@ public class NPC extends AbstractCharacter {
             this.buyPercent = .33f;
             this.sellPercent = 1;
 
-            this.setRot(new Vector3f(0, rs.getFloat("npc_rotation"), 0));
+            // npc_rotation holds cos θ/2
+            this.setRotation(Quaternion.fromYaw((float) Math.acos(rs.getFloat("npc_rotation")) * 2));
 
             this.statLat = rs.getFloat("npc_spawnX");
             this.statAlt = rs.getFloat("npc_spawnY");
@@ -320,14 +323,7 @@ public class NPC extends AbstractCharacter {
         else
             writer.putVector3f(npc.getLoc());
 
-        //Rotation
-        float radians = (float) Math.acos(npc.getRot().y) * 2;
-
-        if (npc.building != null)
-            if (npc.building.getBounds() != null && npc.building.getBounds().getQuaternion() != null)
-                radians += (npc.building.getBounds().getQuaternion()).angleY;
-
-        writer.putFloat(radians);
+        writer.putFloat(npc.getClientYaw());
 
         //Running Speed
         writer.putInt(0);