diff --git a/interface/src/avatar/AvatarMotionState.cpp b/interface/src/avatar/AvatarMotionState.cpp
index 06da384a94..b106ee6398 100644
--- a/interface/src/avatar/AvatarMotionState.cpp
+++ b/interface/src/avatar/AvatarMotionState.cpp
@@ -148,10 +148,6 @@ QUuid AvatarMotionState::getSimulatorID() const {
     return _avatar->getSessionUUID();
 }
 
-// virtual
-void AvatarMotionState::bump() {
-}
-
 // virtual 
 int16_t AvatarMotionState::computeCollisionGroup() {
     return COLLISION_GROUP_OTHER_AVATAR;
diff --git a/interface/src/avatar/AvatarMotionState.h b/interface/src/avatar/AvatarMotionState.h
index 79a4d23179..ac813e764c 100644
--- a/interface/src/avatar/AvatarMotionState.h
+++ b/interface/src/avatar/AvatarMotionState.h
@@ -55,7 +55,6 @@ public:
     virtual const QUuid& getObjectID() const;
 
     virtual QUuid getSimulatorID() const;
-    virtual void bump();
 
     void setBoundingBox(const glm::vec3& corner, const glm::vec3& diagonal);
 
diff --git a/libraries/entities/src/EntityItem.cpp b/libraries/entities/src/EntityItem.cpp
index 61d045769e..508adbb1f2 100644
--- a/libraries/entities/src/EntityItem.cpp
+++ b/libraries/entities/src/EntityItem.cpp
@@ -9,6 +9,8 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+#include "EntityItem.h"
+
 #include <QtCore/QObject>
 
 #include <glm/gtx/transform.hpp>
@@ -22,12 +24,15 @@
 #include <SoundCache.h>
 
 #include "EntityScriptingInterface.h"
-#include "EntityItem.h"
 #include "EntitiesLogging.h"
 #include "EntityTree.h"
 #include "EntitySimulation.h"
 #include "EntityActionFactoryInterface.h"
 
+
+const quint64 DEFAULT_SIMULATOR_CHANGE_LOCKOUT_PERIOD = (quint64)(0.2f * USECS_PER_SECOND);
+const quint64 MAX_SIMULATOR_CHANGE_LOCKOUT_PERIOD = 2 * USECS_PER_SECOND;
+
 bool EntityItem::_sendPhysicsUpdates = true;
 int EntityItem::_maxActionDataSize = 800;
 
@@ -66,8 +71,7 @@ EntityItem::EntityItem(const EntityItemID& entityItemID) :
     _collisionsWillMove(ENTITY_ITEM_DEFAULT_COLLISIONS_WILL_MOVE),
     _locked(ENTITY_ITEM_DEFAULT_LOCKED),
     _userData(ENTITY_ITEM_DEFAULT_USER_DATA),
-    _simulatorID(ENTITY_ITEM_DEFAULT_SIMULATOR_ID),
-    _simulatorIDChangedTime(0),
+    _simulationOwner(),
     _marketplaceID(ENTITY_ITEM_DEFAULT_MARKETPLACE_ID),
     _name(ENTITY_ITEM_DEFAULT_NAME),
     _href(""),
@@ -105,13 +109,16 @@ EntityItem::~EntityItem() {
 EntityPropertyFlags EntityItem::getEntityProperties(EncodeBitstreamParams& params) const {
     EntityPropertyFlags requestedProperties;
 
+    requestedProperties += PROP_SIMULATION_OWNER;
     requestedProperties += PROP_POSITION;
-    requestedProperties += PROP_DIMENSIONS; // NOTE: PROP_RADIUS obsolete
     requestedProperties += PROP_ROTATION;
-    requestedProperties += PROP_DENSITY;
     requestedProperties += PROP_VELOCITY;
-    requestedProperties += PROP_GRAVITY;
+    requestedProperties += PROP_ANGULAR_VELOCITY;
     requestedProperties += PROP_ACCELERATION;
+
+    requestedProperties += PROP_DIMENSIONS; // NOTE: PROP_RADIUS obsolete
+    requestedProperties += PROP_DENSITY;
+    requestedProperties += PROP_GRAVITY;
     requestedProperties += PROP_DAMPING;
     requestedProperties += PROP_RESTITUTION;
     requestedProperties += PROP_FRICTION;
@@ -120,7 +127,6 @@ EntityPropertyFlags EntityItem::getEntityProperties(EncodeBitstreamParams& param
     requestedProperties += PROP_SCRIPT_TIMESTAMP;
     requestedProperties += PROP_COLLISION_SOUND_URL;
     requestedProperties += PROP_REGISTRATION_POINT;
-    requestedProperties += PROP_ANGULAR_VELOCITY;
     requestedProperties += PROP_ANGULAR_DAMPING;
     requestedProperties += PROP_VISIBLE;
     requestedProperties += PROP_IGNORE_FOR_COLLISIONS;
@@ -129,7 +135,6 @@ EntityPropertyFlags EntityItem::getEntityProperties(EncodeBitstreamParams& param
     requestedProperties += PROP_USER_DATA;
     requestedProperties += PROP_MARKETPLACE_ID;
     requestedProperties += PROP_NAME;
-    requestedProperties += PROP_SIMULATOR_ID;
     requestedProperties += PROP_HREF;
     requestedProperties += PROP_DESCRIPTION;
     requestedProperties += PROP_ACTION_DATA;
@@ -238,13 +243,16 @@ OctreeElement::AppendState EntityItem::appendEntityData(OctreePacketData* packet
         //      PROP_PAGED_PROPERTY,
         //      PROP_CUSTOM_PROPERTIES_INCLUDED,
 
+        APPEND_ENTITY_PROPERTY(PROP_SIMULATION_OWNER, _simulationOwner.toByteArray());
         APPEND_ENTITY_PROPERTY(PROP_POSITION, getPosition());
-        APPEND_ENTITY_PROPERTY(PROP_DIMENSIONS, getDimensions()); // NOTE: PROP_RADIUS obsolete
         APPEND_ENTITY_PROPERTY(PROP_ROTATION, getRotation());
-        APPEND_ENTITY_PROPERTY(PROP_DENSITY, getDensity());
         APPEND_ENTITY_PROPERTY(PROP_VELOCITY, getVelocity());
-        APPEND_ENTITY_PROPERTY(PROP_GRAVITY, getGravity());
+        APPEND_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, getAngularVelocity());
         APPEND_ENTITY_PROPERTY(PROP_ACCELERATION, getAcceleration());
+
+        APPEND_ENTITY_PROPERTY(PROP_DIMENSIONS, getDimensions()); // NOTE: PROP_RADIUS obsolete
+        APPEND_ENTITY_PROPERTY(PROP_DENSITY, getDensity());
+        APPEND_ENTITY_PROPERTY(PROP_GRAVITY, getGravity());
         APPEND_ENTITY_PROPERTY(PROP_DAMPING, getDamping());
         APPEND_ENTITY_PROPERTY(PROP_RESTITUTION, getRestitution());
         APPEND_ENTITY_PROPERTY(PROP_FRICTION, getFriction());
@@ -252,14 +260,12 @@ OctreeElement::AppendState EntityItem::appendEntityData(OctreePacketData* packet
         APPEND_ENTITY_PROPERTY(PROP_SCRIPT, getScript());
         APPEND_ENTITY_PROPERTY(PROP_SCRIPT_TIMESTAMP, getScriptTimestamp());
         APPEND_ENTITY_PROPERTY(PROP_REGISTRATION_POINT, getRegistrationPoint());
-        APPEND_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, getAngularVelocity());
         APPEND_ENTITY_PROPERTY(PROP_ANGULAR_DAMPING, getAngularDamping());
         APPEND_ENTITY_PROPERTY(PROP_VISIBLE, getVisible());
         APPEND_ENTITY_PROPERTY(PROP_IGNORE_FOR_COLLISIONS, getIgnoreForCollisions());
         APPEND_ENTITY_PROPERTY(PROP_COLLISIONS_WILL_MOVE, getCollisionsWillMove());
         APPEND_ENTITY_PROPERTY(PROP_LOCKED, getLocked());
         APPEND_ENTITY_PROPERTY(PROP_USER_DATA, getUserData());
-        APPEND_ENTITY_PROPERTY(PROP_SIMULATOR_ID, getSimulatorID());
         APPEND_ENTITY_PROPERTY(PROP_MARKETPLACE_ID, getMarketplaceID());
         APPEND_ENTITY_PROPERTY(PROP_NAME, getName());
         APPEND_ENTITY_PROPERTY(PROP_COLLISION_SOUND_URL, getCollisionSoundURL());
@@ -329,8 +335,8 @@ int EntityItem::expectedBytes() {
 }
 
 
+// clients use this method to unpack FULL updates from entity-server
 int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLeftToRead, ReadBitstreamToTreeParams& args) {
-
     if (args.bitstreamVersion < VERSION_ENTITIES_SUPPORT_SPLIT_MTU) {
     
         // NOTE: This shouldn't happen. The only versions of the bit stream that didn't support split mtu buffers should
@@ -354,14 +360,9 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
         return 0;
     }
 
-    // if this bitstream indicates that this node is the simulation owner, ignore any physics-related updates.
-    glm::vec3 savePosition = getPosition();
-    glm::quat saveRotation = getRotation();
-    glm::vec3 saveVelocity = _velocity;
-    glm::vec3 saveAngularVelocity = _angularVelocity;
-
     int originalLength = bytesLeftToRead;
-    QByteArray originalDataBuffer((const char*)data, originalLength);
+    // TODO: figure out a way to avoid the big deep copy below.
+    QByteArray originalDataBuffer((const char*)data, originalLength); // big deep copy!
 
     int clockSkew = args.sourceNode ? args.sourceNode->getClockSkewUsec() : 0;
 
@@ -539,40 +540,70 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     EntityPropertyFlags propertyFlags = encodedPropertyFlags;
     dataAt += propertyFlags.getEncodedLength();
     bytesRead += propertyFlags.getEncodedLength();
-    READ_ENTITY_PROPERTY(PROP_POSITION, glm::vec3, updatePosition);
 
-    // Old bitstreams had PROP_RADIUS, new bitstreams have PROP_DIMENSIONS
-    if (args.bitstreamVersion < VERSION_ENTITIES_SUPPORT_DIMENSIONS) {
-        if (propertyFlags.getHasProperty(PROP_RADIUS)) {
-            float fromBuffer;
-            memcpy(&fromBuffer, dataAt, sizeof(fromBuffer));
-            dataAt += sizeof(fromBuffer);
-            bytesRead += sizeof(fromBuffer);
-            if (overwriteLocalData) {
-                setRadius(fromBuffer);
+    if (args.bitstreamVersion >= VERSION_ENTITIES_HAVE_SIMULATION_OWNER) {
+        // pack SimulationOwner and terse update properties near each other
+
+        // NOTE: the server is authoritative for changes to simOwnerID so we always unpack ownership data
+        // even when we would otherwise ignore the rest of the packet.
+
+        if (propertyFlags.getHasProperty(PROP_SIMULATION_OWNER)) {
+            QByteArray simOwnerData;
+            int bytes = OctreePacketData::unpackDataFromBytes(dataAt, simOwnerData);
+            SimulationOwner newSimOwner;
+            newSimOwner.fromByteArray(simOwnerData);
+            dataAt += bytes;
+            bytesRead += bytes;
+
+            if (_simulationOwner.set(newSimOwner)) {
+                _dirtyFlags |= EntityItem::DIRTY_SIMULATOR_ID;
             }
         }
-    } else {
+        {   // When we own the simulation we don't accept updates to the entity's transform/velocities
+            // but since we're using macros below we have to temporarily modify overwriteLocalData.
+            auto nodeList = DependencyManager::get<NodeList>();
+            bool weOwnIt = _simulationOwner.matchesValidID(nodeList->getSessionUUID());
+            bool oldOverwrite = overwriteLocalData;
+            overwriteLocalData = overwriteLocalData && !weOwnIt;
+            READ_ENTITY_PROPERTY(PROP_POSITION, glm::vec3, updatePosition);
+            READ_ENTITY_PROPERTY(PROP_ROTATION, glm::quat, updateRotation);
+            READ_ENTITY_PROPERTY(PROP_VELOCITY, glm::vec3, updateVelocity);
+            READ_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, glm::vec3, updateAngularVelocity);
+            READ_ENTITY_PROPERTY(PROP_ACCELERATION, glm::vec3, setAcceleration);
+            overwriteLocalData = oldOverwrite;
+        }
+
         READ_ENTITY_PROPERTY(PROP_DIMENSIONS, glm::vec3, updateDimensions);
-    }
-
-    READ_ENTITY_PROPERTY(PROP_ROTATION, glm::quat, updateRotation);
-    READ_ENTITY_PROPERTY(PROP_DENSITY, float, updateDensity);
-    READ_ENTITY_PROPERTY(PROP_VELOCITY, glm::vec3, updateVelocity);
-    READ_ENTITY_PROPERTY(PROP_GRAVITY, glm::vec3, updateGravity);
-    if (args.bitstreamVersion >= VERSION_ENTITIES_HAVE_ACCELERATION) {
+        READ_ENTITY_PROPERTY(PROP_DENSITY, float, updateDensity);
+        READ_ENTITY_PROPERTY(PROP_GRAVITY, glm::vec3, updateGravity);
+    
+        READ_ENTITY_PROPERTY(PROP_DAMPING, float, updateDamping);
+        READ_ENTITY_PROPERTY(PROP_RESTITUTION, float, updateRestitution);
+        READ_ENTITY_PROPERTY(PROP_FRICTION, float, updateFriction);
+        READ_ENTITY_PROPERTY(PROP_LIFETIME, float, updateLifetime);
+        READ_ENTITY_PROPERTY(PROP_SCRIPT, QString, setScript);
+        READ_ENTITY_PROPERTY(PROP_SCRIPT_TIMESTAMP, quint64, setScriptTimestamp);
+        READ_ENTITY_PROPERTY(PROP_REGISTRATION_POINT, glm::vec3, setRegistrationPoint);
+    } else {
+        // legacy order of packing here
+        READ_ENTITY_PROPERTY(PROP_POSITION, glm::vec3, updatePosition);
+        READ_ENTITY_PROPERTY(PROP_DIMENSIONS, glm::vec3, updateDimensions);
+        READ_ENTITY_PROPERTY(PROP_ROTATION, glm::quat, updateRotation);
+        READ_ENTITY_PROPERTY(PROP_DENSITY, float, updateDensity);
+        READ_ENTITY_PROPERTY(PROP_VELOCITY, glm::vec3, updateVelocity);
+        READ_ENTITY_PROPERTY(PROP_GRAVITY, glm::vec3, updateGravity);
         READ_ENTITY_PROPERTY(PROP_ACCELERATION, glm::vec3, setAcceleration);
+
+        READ_ENTITY_PROPERTY(PROP_DAMPING, float, updateDamping);
+        READ_ENTITY_PROPERTY(PROP_RESTITUTION, float, updateRestitution);
+        READ_ENTITY_PROPERTY(PROP_FRICTION, float, updateFriction);
+        READ_ENTITY_PROPERTY(PROP_LIFETIME, float, updateLifetime);
+        READ_ENTITY_PROPERTY(PROP_SCRIPT, QString, setScript);
+        READ_ENTITY_PROPERTY(PROP_SCRIPT_TIMESTAMP, quint64, setScriptTimestamp);
+        READ_ENTITY_PROPERTY(PROP_REGISTRATION_POINT, glm::vec3, setRegistrationPoint);
+        READ_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, glm::vec3, updateAngularVelocity);
     }
 
-    READ_ENTITY_PROPERTY(PROP_DAMPING, float, updateDamping);
-    READ_ENTITY_PROPERTY(PROP_RESTITUTION, float, updateRestitution);
-    READ_ENTITY_PROPERTY(PROP_FRICTION, float, updateFriction);
-    READ_ENTITY_PROPERTY(PROP_LIFETIME, float, updateLifetime);
-    READ_ENTITY_PROPERTY(PROP_SCRIPT, QString, setScript);
-    READ_ENTITY_PROPERTY(PROP_SCRIPT_TIMESTAMP, quint64, setScriptTimestamp);
-    READ_ENTITY_PROPERTY(PROP_REGISTRATION_POINT, glm::vec3, setRegistrationPoint);
-    READ_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, glm::vec3, updateAngularVelocity);
-    //READ_ENTITY_PROPERTY(PROP_ANGULAR_VELOCITY, glm::vec3, updateAngularVelocityInDegrees);
     READ_ENTITY_PROPERTY(PROP_ANGULAR_DAMPING, float, updateAngularDamping);
     READ_ENTITY_PROPERTY(PROP_VISIBLE, bool, setVisible);
     READ_ENTITY_PROPERTY(PROP_IGNORE_FOR_COLLISIONS, bool, updateIgnoreForCollisions);
@@ -580,12 +611,14 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     READ_ENTITY_PROPERTY(PROP_LOCKED, bool, setLocked);
     READ_ENTITY_PROPERTY(PROP_USER_DATA, QString, setUserData);
 
-    if (args.bitstreamVersion >= VERSION_ENTITIES_HAVE_ACCELERATION) {
+    if (args.bitstreamVersion < VERSION_ENTITIES_HAVE_SIMULATION_OWNER) {
+        // this code for when there is only simulatorID and no simulation priority
+
         // we always accept the server's notion of simulatorID, so we fake overwriteLocalData as true
         // before we try to READ_ENTITY_PROPERTY it
         bool temp = overwriteLocalData;
         overwriteLocalData = true;
-        READ_ENTITY_PROPERTY(PROP_SIMULATOR_ID, QUuid, updateSimulatorID);
+        READ_ENTITY_PROPERTY(PROP_SIMULATION_OWNER, QUuid, updateSimulatorID);
         overwriteLocalData = temp;
     }
 
@@ -628,7 +661,6 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
             #ifdef WANT_DEBUG
                 qCDebug(entities) << "skipTimeForward:" << skipTimeForward;
             #endif
-
             // we want to extrapolate the motion forward to compensate for packet travel time, but
             // we don't want the side effect of flag setting.
             simulateKinematicMotion(skipTimeForward, false);
@@ -638,15 +670,8 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     auto nodeList = DependencyManager::get<NodeList>();
     const QUuid& myNodeID = nodeList->getSessionUUID();
     if (overwriteLocalData) {
-        if (_simulatorID == myNodeID && !_simulatorID.isNull()) {
-            // we own the simulation, so we keep our transform+velocities and remove any related dirty flags
-            // rather than accept the values in the packet
-            setPosition(savePosition);
-            setRotation(saveRotation);
-            _velocity = saveVelocity;
-            _angularVelocity = saveAngularVelocity;
-            _dirtyFlags &= ~(EntityItem::DIRTY_TRANSFORM | EntityItem::DIRTY_VELOCITIES);
-        } else {
+        if (!_simulationOwner.matchesValidID(myNodeID)) {
+            
             _lastSimulated = now;
         }
     }
@@ -910,6 +935,7 @@ EntityItemProperties EntityItem::getProperties() const {
 
     properties._type = getType();
     
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(simulationOwner, getSimulationOwner);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(position, getPosition);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(dimensions, getDimensions); // NOTE: radius is obsolete
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(rotation, getRotation);
@@ -935,7 +961,6 @@ EntityItemProperties EntityItem::getProperties() const {
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(collisionsWillMove, getCollisionsWillMove);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(locked, getLocked);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(userData, getUserData);
-    COPY_ENTITY_PROPERTY_TO_PROPERTIES(simulatorID, getSimulatorID);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(marketplaceID, getMarketplaceID);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(name, getName);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(href, getHref);
@@ -966,6 +991,7 @@ bool EntityItem::setProperties(const EntityItemProperties& properties) {
     bool somethingChanged = false;
 
     // these affect TerseUpdate properties
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(simulationOwner, setSimulationOwner);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(position, updatePosition);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(rotation, updateRotation);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(velocity, updateVelocity);
@@ -987,7 +1013,6 @@ bool EntityItem::setProperties(const EntityItemProperties& properties) {
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(collisionsWillMove, updateCollisionsWillMove);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(created, updateCreated);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(lifetime, updateLifetime);
-    SET_ENTITY_PROPERTY_FROM_PROPERTIES(simulatorID, updateSimulatorID);
 
     // non-simulation properties below
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(script, setScript);
@@ -1363,19 +1388,28 @@ void EntityItem::updateCreated(uint64_t value) {
     }
 }
 
-void EntityItem::setSimulatorID(const QUuid& value) {
-    _simulatorID = value;
-    _simulatorIDChangedTime = usecTimestampNow();
+void EntityItem::setSimulationOwner(const QUuid& id, quint8 priority) {
+    _simulationOwner.set(id, priority);
+}
+
+void EntityItem::setSimulationOwner(const SimulationOwner& owner) {
+    _simulationOwner.set(owner);
 }
 
 void EntityItem::updateSimulatorID(const QUuid& value) {
-    if (_simulatorID != value) {
-        _simulatorID = value;
-        _simulatorIDChangedTime = usecTimestampNow();
+    if (_simulationOwner.setID(value)) {
         _dirtyFlags |= EntityItem::DIRTY_SIMULATOR_ID;
     }
 }
 
+void EntityItem::clearSimulationOwnership() {
+    _simulationOwner.clear();
+    // don't bother setting the DIRTY_SIMULATOR_ID flag because clearSimulationOwnership() 
+    // is only ever called entity-server-side and the flags are only used client-side
+    //_dirtyFlags |= EntityItem::DIRTY_SIMULATOR_ID;
+
+}
+
 bool EntityItem::addAction(EntitySimulation* simulation, EntityActionPointer action) {
     assert(action);
     auto actionOwnerEntity = action->getOwnerEntity().lock();
diff --git a/libraries/entities/src/EntityItem.h b/libraries/entities/src/EntityItem.h
index 6859d4252d..8656a5d4cf 100644
--- a/libraries/entities/src/EntityItem.h
+++ b/libraries/entities/src/EntityItem.h
@@ -29,6 +29,7 @@
 #include "EntityItemProperties.h"
 #include "EntityItemPropertiesDefaults.h"
 #include "EntityTypes.h"
+#include "SimulationOwner.h"
 
 class EntitySimulation;
 class EntityTreeElement;
@@ -60,7 +61,6 @@ const float ACTIVATION_LINEAR_VELOCITY_DELTA = 0.01f;
 const float ACTIVATION_GRAVITY_DELTA = 0.1f;
 const float ACTIVATION_ANGULAR_VELOCITY_DELTA = 0.03f;
 
-
 #define DONT_ALLOW_INSTANTIATION virtual void pureVirtualFunctionPlaceHolder() = 0;
 #define ALLOW_INSTANTIATION virtual void pureVirtualFunctionPlaceHolder() { };
 
@@ -68,7 +68,6 @@ const float ACTIVATION_ANGULAR_VELOCITY_DELTA = 0.03f;
 #define debugTimeOnly(T) qPrintable(QString("%1").arg(T, 16, 10))
 #define debugTreeVector(V) V << "[" << V << " in meters ]"
 
-
 /// EntityItem class this is the base class for all entity types. It handles the basic properties and functionality available
 /// to all other entity types. In particular: postion, size, rotation, age, lifetime, velocity, gravity. You can not instantiate
 /// one directly, instead you must only construct one of it's derived classes with additional features.
@@ -92,8 +91,9 @@ public:
         DIRTY_LIFETIME = 0x0100,
         DIRTY_UPDATEABLE = 0x0200,
         DIRTY_MATERIAL = 0x00400,
-        DIRTY_PHYSICS_ACTIVATION = 0x0800, // we want to activate the object
-        DIRTY_SIMULATOR_ID = 0x1000,
+        DIRTY_PHYSICS_ACTIVATION = 0x0800, // should activate object in physics engine
+        DIRTY_SIMULATOR_OWNERSHIP = 0x1000, // should claim simulator ownership
+        DIRTY_SIMULATOR_ID = 0x2000, // the simulatorID has changed
         DIRTY_TRANSFORM = DIRTY_POSITION | DIRTY_ROTATION,
         DIRTY_VELOCITIES = DIRTY_LINEAR_VELOCITY | DIRTY_ANGULAR_VELOCITY
     };
@@ -317,11 +317,16 @@ public:
 
     const QString& getUserData() const { return _userData; }
     void setUserData(const QString& value) { _userData = value; }
-    
-    QUuid getSimulatorID() const { return _simulatorID; }
-    void setSimulatorID(const QUuid& value);
+
+    const SimulationOwner& getSimulationOwner() const { return _simulationOwner; }
+    void setSimulationOwner(const QUuid& id, quint8 priority);
+    void setSimulationOwner(const SimulationOwner& owner);
+    void promoteSimulationPriority(quint8 priority);
+
+    quint8 getSimulationPriority() const { return _simulationOwner.getPriority(); }
+    QUuid getSimulatorID() const { return _simulationOwner.getID(); }
     void updateSimulatorID(const QUuid& value);
-    quint64 getSimulatorIDChangedTime() const { return _simulatorIDChangedTime; }
+    void clearSimulationOwnership();
 
     const QString& getMarketplaceID() const { return _marketplaceID; }
     void setMarketplaceID(const QString& value) { _marketplaceID = value; }
@@ -358,7 +363,7 @@ public:
     virtual void updateShapeType(ShapeType type) { /* do nothing */ }
 
     uint32_t getDirtyFlags() const { return _dirtyFlags; }
-    void clearDirtyFlags(uint32_t mask = 0xffff) { _dirtyFlags &= ~mask; }
+    void clearDirtyFlags(uint32_t mask = 0xffffffff) { _dirtyFlags &= ~mask; }
 
     bool isMoving() const;
 
@@ -379,6 +384,8 @@ public:
 
     void getAllTerseUpdateProperties(EntityItemProperties& properties) const;
 
+    void flagForOwnership() { _dirtyFlags |= DIRTY_SIMULATOR_OWNERSHIP; }
+
     bool addAction(EntitySimulation* simulation, EntityActionPointer action);
     bool updateAction(EntitySimulation* simulation, const QUuid& actionID, const QVariantMap& arguments);
     bool removeAction(EntitySimulation* simulation, const QUuid& actionID);
@@ -431,8 +438,7 @@ protected:
     bool _collisionsWillMove;
     bool _locked;
     QString _userData;
-    QUuid _simulatorID; // id of Node which is currently responsible for simulating this Entity
-    quint64 _simulatorIDChangedTime; // when was _simulatorID last updated?
+    SimulationOwner _simulationOwner;
     QString _marketplaceID;
     QString _name;
     QString _href; //Hyperlink href
diff --git a/libraries/entities/src/EntityItemProperties.cpp b/libraries/entities/src/EntityItemProperties.cpp
index 9956937a3f..9a1a5494b7 100644
--- a/libraries/entities/src/EntityItemProperties.cpp
+++ b/libraries/entities/src/EntityItemProperties.cpp
@@ -38,7 +38,7 @@ EntityPropertyList PROP_LAST_ITEM = (EntityPropertyList)(PROP_AFTER_LAST_ITEM -
 EntityItemProperties::EntityItemProperties() :
 
 CONSTRUCT_PROPERTY(visible, ENTITY_ITEM_DEFAULT_VISIBLE),
-CONSTRUCT_PROPERTY(position, 0),
+CONSTRUCT_PROPERTY(position, 0.0f),
 CONSTRUCT_PROPERTY(dimensions, ENTITY_ITEM_DEFAULT_DIMENSIONS),
 CONSTRUCT_PROPERTY(rotation, ENTITY_ITEM_DEFAULT_ROTATION),
 CONSTRUCT_PROPERTY(density, ENTITY_ITEM_DEFAULT_DENSITY),
@@ -73,7 +73,7 @@ CONSTRUCT_PROPERTY(locked, ENTITY_ITEM_DEFAULT_LOCKED),
 CONSTRUCT_PROPERTY(textures, ""),
 CONSTRUCT_PROPERTY(animationSettings, ""),
 CONSTRUCT_PROPERTY(userData, ENTITY_ITEM_DEFAULT_USER_DATA),
-CONSTRUCT_PROPERTY(simulatorID, ENTITY_ITEM_DEFAULT_SIMULATOR_ID),
+CONSTRUCT_PROPERTY(simulationOwner, SimulationOwner()),
 CONSTRUCT_PROPERTY(text, TextEntityItem::DEFAULT_TEXT),
 CONSTRUCT_PROPERTY(lineHeight, TextEntityItem::DEFAULT_LINE_HEIGHT),
 CONSTRUCT_PROPERTY(textColor, TextEntityItem::DEFAULT_TEXT_COLOR),
@@ -288,8 +288,8 @@ void EntityItemProperties::setBackgroundModeFromString(const QString& background
 EntityPropertyFlags EntityItemProperties::getChangedProperties() const {
     EntityPropertyFlags changedProperties;
     
-    CHECK_PROPERTY_CHANGE(PROP_DIMENSIONS, dimensions);
     CHECK_PROPERTY_CHANGE(PROP_POSITION, position);
+    CHECK_PROPERTY_CHANGE(PROP_DIMENSIONS, dimensions);
     CHECK_PROPERTY_CHANGE(PROP_ROTATION, rotation);
     CHECK_PROPERTY_CHANGE(PROP_DENSITY, density);
     CHECK_PROPERTY_CHANGE(PROP_VELOCITY, velocity);
@@ -323,7 +323,7 @@ EntityPropertyFlags EntityItemProperties::getChangedProperties() const {
     CHECK_PROPERTY_CHANGE(PROP_LOCKED, locked);
     CHECK_PROPERTY_CHANGE(PROP_TEXTURES, textures);
     CHECK_PROPERTY_CHANGE(PROP_USER_DATA, userData);
-    CHECK_PROPERTY_CHANGE(PROP_SIMULATOR_ID, simulatorID);
+    CHECK_PROPERTY_CHANGE(PROP_SIMULATION_OWNER, simulationOwner);
     CHECK_PROPERTY_CHANGE(PROP_TEXT, text);
     CHECK_PROPERTY_CHANGE(PROP_LINE_HEIGHT, lineHeight);
     CHECK_PROPERTY_CHANGE(PROP_TEXT_COLOR, textColor);
@@ -419,7 +419,7 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
     COPY_PROPERTY_TO_QSCRIPTVALUE(locked);
     COPY_PROPERTY_TO_QSCRIPTVALUE(textures);
     COPY_PROPERTY_TO_QSCRIPTVALUE(userData);
-    COPY_PROPERTY_TO_QSCRIPTVALUE_GETTER(simulatorID, getSimulatorIDAsString());
+    //COPY_PROPERTY_TO_QSCRIPTVALUE(simulationOwner); // TODO: expose this for JSON saves?
     COPY_PROPERTY_TO_QSCRIPTVALUE(text);
     COPY_PROPERTY_TO_QSCRIPTVALUE(lineHeight);
     COPY_PROPERTY_TO_QSCRIPTVALUE_GETTER(textColor, getTextColor());
@@ -572,7 +572,8 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
                 auto result = QDateTime::fromMSecsSinceEpoch(_created / 1000, Qt::UTC); // usec per msec
                 return result;
             });
-        COPY_PROPERTY_FROM_QSCRIPTVALUE(simulatorID, QUuid, setSimulatorID);
+        // TODO: expose this to QScriptValue for JSON saves?
+        //COPY_PROPERTY_FROM_QSCRIPTVALUE(simulationOwner, ???, setSimulatorPriority);
     }
 
     _stage.copyFromScriptValue(object, _defaultSettings);
@@ -707,6 +708,7 @@ bool EntityItemProperties::encodeEntityEditPacket(PacketType command, EntityItem
             //      PROP_PAGED_PROPERTY,
             //      PROP_CUSTOM_PROPERTIES_INCLUDED,
             
+            APPEND_ENTITY_PROPERTY(PROP_SIMULATION_OWNER, properties._simulationOwner.toByteArray());
             APPEND_ENTITY_PROPERTY(PROP_POSITION, properties.getPosition());
             APPEND_ENTITY_PROPERTY(PROP_DIMENSIONS, properties.getDimensions()); // NOTE: PROP_RADIUS obsolete
             APPEND_ENTITY_PROPERTY(PROP_ROTATION, properties.getRotation());
@@ -729,7 +731,6 @@ bool EntityItemProperties::encodeEntityEditPacket(PacketType command, EntityItem
             APPEND_ENTITY_PROPERTY(PROP_COLLISIONS_WILL_MOVE, properties.getCollisionsWillMove());
             APPEND_ENTITY_PROPERTY(PROP_LOCKED, properties.getLocked());
             APPEND_ENTITY_PROPERTY(PROP_USER_DATA, properties.getUserData());
-            APPEND_ENTITY_PROPERTY(PROP_SIMULATOR_ID, properties.getSimulatorID());
             APPEND_ENTITY_PROPERTY(PROP_HREF, properties.getHref());
             APPEND_ENTITY_PROPERTY(PROP_DESCRIPTION, properties.getDescription());
             
@@ -962,7 +963,8 @@ bool EntityItemProperties::decodeEntityEditPacket(const unsigned char* data, int
     EntityPropertyFlags propertyFlags = encodedPropertyFlags;
     dataAt += propertyFlags.getEncodedLength();
     processedBytes += propertyFlags.getEncodedLength();
-    
+
+    READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_SIMULATION_OWNER, QByteArray, setSimulationOwner);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_POSITION, glm::vec3, setPosition);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_DIMENSIONS, glm::vec3, setDimensions);  // NOTE: PROP_RADIUS obsolete
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_ROTATION, glm::quat, setRotation);
@@ -985,7 +987,6 @@ bool EntityItemProperties::decodeEntityEditPacket(const unsigned char* data, int
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_COLLISIONS_WILL_MOVE, bool, setCollisionsWillMove);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_LOCKED, bool, setLocked);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_USER_DATA, QString, setUserData);
-    READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_SIMULATOR_ID, QUuid, setSimulatorID);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_HREF, QString, setHref);
     READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_DESCRIPTION, QString, setDescription);
     
@@ -1102,6 +1103,7 @@ bool EntityItemProperties::encodeEraseEntityMessage(const EntityItemID& entityIt
 }
 
 void EntityItemProperties::markAllChanged() {
+    _simulationOwnerChanged = true;
     _positionChanged = true;
     _dimensionsChanged = true;
     _rotationChanged = true;
@@ -1114,7 +1116,6 @@ void EntityItemProperties::markAllChanged() {
     _frictionChanged = true;
     _lifetimeChanged = true;
     _userDataChanged = true;
-    _simulatorIDChanged = true;
     _scriptChanged = true;
     _scriptTimestampChanged = true;
     _collisionSoundURLChanged = true;
@@ -1230,3 +1231,27 @@ bool EntityItemProperties::hasTerseUpdateChanges() const {
     // a TerseUpdate includes the transform and its derivatives
     return _positionChanged || _velocityChanged || _rotationChanged || _angularVelocityChanged || _accelerationChanged;
 }
+
+bool EntityItemProperties::hasMiscPhysicsChanges() const {
+    return _gravityChanged || _dimensionsChanged || _densityChanged || _frictionChanged 
+        || _restitutionChanged || _dampingChanged || _angularDampingChanged || _registrationPointChanged ||
+        _compoundShapeURLChanged || _collisionsWillMoveChanged || _ignoreForCollisionsChanged;
+}
+
+void EntityItemProperties::clearSimulationOwner() {
+    _simulationOwner.clear();
+    _simulationOwnerChanged = true;
+}
+
+void EntityItemProperties::setSimulationOwner(const QUuid& id, uint8_t priority) {
+    if (!_simulationOwner.matchesValidID(id) || _simulationOwner.getPriority() != priority) {
+        _simulationOwner.set(id, priority);
+        _simulationOwnerChanged = true;
+    }
+}
+
+void EntityItemProperties::setSimulationOwner(const QByteArray& data) {
+    if (_simulationOwner.fromByteArray(data)) {
+        _simulationOwnerChanged = true;
+    }
+}
diff --git a/libraries/entities/src/EntityItemProperties.h b/libraries/entities/src/EntityItemProperties.h
index 570d14d709..b8200d025c 100644
--- a/libraries/entities/src/EntityItemProperties.h
+++ b/libraries/entities/src/EntityItemProperties.h
@@ -34,6 +34,7 @@
 #include "EntityItemPropertiesMacros.h"
 #include "EntityTypes.h"
 #include "EntityPropertyFlags.h"
+#include "SimulationOwner.h"
 #include "SkyboxPropertyGroup.h"
 #include "StagePropertyGroup.h"
 
@@ -120,7 +121,7 @@ public:
     DEFINE_PROPERTY_REF(PROP_TEXTURES, Textures, textures, QString);
     DEFINE_PROPERTY_REF_WITH_SETTER_AND_GETTER(PROP_ANIMATION_SETTINGS, AnimationSettings, animationSettings, QString);
     DEFINE_PROPERTY_REF(PROP_USER_DATA, UserData, userData, QString);
-    DEFINE_PROPERTY_REF(PROP_SIMULATOR_ID, SimulatorID, simulatorID, QUuid);
+    DEFINE_PROPERTY_REF(PROP_SIMULATION_OWNER, SimulationOwner, simulationOwner, SimulationOwner);
     DEFINE_PROPERTY_REF(PROP_TEXT, Text, text, QString);
     DEFINE_PROPERTY(PROP_LINE_HEIGHT, LineHeight, lineHeight, float);
     DEFINE_PROPERTY_REF(PROP_TEXT_COLOR, TextColor, textColor, xColor);
@@ -197,7 +198,7 @@ public:
     const QStringList& getTextureNames() const { return _textureNames; }
     void setTextureNames(const QStringList& value) { _textureNames = value; }
 
-    QString getSimulatorIDAsString() const { return _simulatorID.toString().mid(1,36).toUpper(); }
+    QString getSimulatorIDAsString() const { return _simulationOwner.getID().toString().mid(1,36).toUpper(); }
 
     void setVoxelDataDirty() { _voxelDataChanged = true; }
     
@@ -206,6 +207,12 @@ public:
     void setCreated(QDateTime& v);
 
     bool hasTerseUpdateChanges() const;
+    bool hasMiscPhysicsChanges() const;
+
+    void clearSimulationOwner();
+    void setSimulationOwner(const QUuid& id, uint8_t priority);
+    void setSimulationOwner(const QByteArray& data);
+    void promoteSimulationPriority(quint8 priority) { _simulationOwner.promotePriority(priority); }
 
     void setActionDataDirty() { _actionDataChanged = true; }
 
@@ -287,7 +294,7 @@ inline QDebug operator<<(QDebug debug, const EntityItemProperties& properties) {
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, Locked, locked, "");
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, Textures, textures, "");
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, UserData, userData, "");
-    DEBUG_PROPERTY_IF_CHANGED(debug, properties, SimulatorID, simulatorID, QUuid());
+    DEBUG_PROPERTY_IF_CHANGED(debug, properties, SimulationOwner, simulationOwner, SimulationOwner());
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, Text, text, "");
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, LineHeight, lineHeight, "");
     DEBUG_PROPERTY_IF_CHANGED(debug, properties, TextColor, textColor, "");
diff --git a/libraries/entities/src/EntityPropertyFlags.h b/libraries/entities/src/EntityPropertyFlags.h
index 363b36d34f..be16683f39 100644
--- a/libraries/entities/src/EntityPropertyFlags.h
+++ b/libraries/entities/src/EntityPropertyFlags.h
@@ -104,7 +104,7 @@ enum EntityPropertyList {
     PROP_COMPOUND_SHAPE_URL, // used by Model + zones entities
     PROP_MARKETPLACE_ID, // all entities
     PROP_ACCELERATION, // all entities
-    PROP_SIMULATOR_ID, // all entities
+    PROP_SIMULATION_OWNER, // formerly known as PROP_SIMULATOR_ID
     PROP_NAME, // all entities
     PROP_COLLISION_SOUND_URL,
     PROP_RESTITUTION,
diff --git a/libraries/entities/src/EntityScriptingInterface.cpp b/libraries/entities/src/EntityScriptingInterface.cpp
index bc89e74863..51c698e7e8 100644
--- a/libraries/entities/src/EntityScriptingInterface.cpp
+++ b/libraries/entities/src/EntityScriptingInterface.cpp
@@ -9,18 +9,20 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+#include "EntityScriptingInterface.h"
+
 #include <VariantMapToScriptValue.h>
 
+#include "EntitiesLogging.h"
+#include "EntityActionFactoryInterface.h"
+#include "EntityActionInterface.h"
+#include "EntitySimulation.h"
 #include "EntityTree.h"
 #include "LightEntityItem.h"
 #include "ModelEntityItem.h"
+#include "SimulationOwner.h"
 #include "ZoneEntityItem.h"
-#include "EntitiesLogging.h"
-#include "EntitySimulation.h"
-#include "EntityActionInterface.h"
-#include "EntityActionFactoryInterface.h"
 
-#include "EntityScriptingInterface.h"
 
 EntityScriptingInterface::EntityScriptingInterface() :
     _entityTree(NULL)
@@ -61,16 +63,6 @@ void EntityScriptingInterface::setEntityTree(EntityTree* modelTree) {
     }
 }
 
-void bidForSimulationOwnership(EntityItemProperties& properties) {
-    // We make a bid for simulation ownership by declaring our sessionID as simulation owner
-    // in the outgoing properties.  The EntityServer may accept the bid or might not.
-    auto nodeList = DependencyManager::get<NodeList>();
-    const QUuid myNodeID = nodeList->getSessionUUID();
-    properties.setSimulatorID(myNodeID);
-}
-
-
-
 QUuid EntityScriptingInterface::addEntity(const EntityItemProperties& properties) {
 
     EntityItemProperties propertiesWithSimID = properties;
@@ -83,11 +75,15 @@ QUuid EntityScriptingInterface::addEntity(const EntityItemProperties& properties
         _entityTree->lockForWrite();
         EntityItemPointer entity = _entityTree->addEntity(id, propertiesWithSimID);
         if (entity) {
-            entity->setLastBroadcast(usecTimestampNow());
             // This Node is creating a new object.  If it's in motion, set this Node as the simulator.
-            bidForSimulationOwnership(propertiesWithSimID);
+            auto nodeList = DependencyManager::get<NodeList>();
+            const QUuid myNodeID = nodeList->getSessionUUID();
+            propertiesWithSimID.setSimulationOwner(myNodeID, SCRIPT_EDIT_SIMULATION_PRIORITY);
+
             // and make note of it now, so we can act on it right away.
-            entity->setSimulatorID(propertiesWithSimID.getSimulatorID());
+            entity->setSimulationOwner(myNodeID, SCRIPT_EDIT_SIMULATION_PRIORITY);
+
+            entity->setLastBroadcast(usecTimestampNow());
         } else {
             qCDebug(entities) << "script failed to add new Entity to local Octree";
             success = false;
@@ -146,23 +142,35 @@ QUuid EntityScriptingInterface::editEntity(QUuid id, EntityItemProperties proper
             if (entity) {
                 // make sure the properties has a type, so that the encode can know which properties to include
                 properties.setType(entity->getType());
-                if (properties.hasTerseUpdateChanges()) {
+                bool hasTerseUpdateChanges = properties.hasTerseUpdateChanges();
+                bool hasPhysicsChanges = properties.hasMiscPhysicsChanges() || hasTerseUpdateChanges;
+                if (hasPhysicsChanges) {
                     auto nodeList = DependencyManager::get<NodeList>();
                     const QUuid myNodeID = nodeList->getSessionUUID();
 
                     if (entity->getSimulatorID() == myNodeID) {
                         // we think we already own the simulation, so make sure to send ALL TerseUpdate properties
-                        entity->getAllTerseUpdateProperties(properties);
-                        // TODO: if we knew that ONLY TerseUpdate properties have changed in properties AND the object
-                        // is dynamic AND it is active in the physics simulation then we could chose to NOT queue an update
+                        if (hasTerseUpdateChanges) {
+                            entity->getAllTerseUpdateProperties(properties);
+                        }
+                        // TODO: if we knew that ONLY TerseUpdate properties have changed in properties AND the object 
+                        // is dynamic AND it is active in the physics simulation then we could chose to NOT queue an update 
                         // and instead let the physics simulation decide when to send a terse update.  This would remove
                         // the "slide-no-rotate" glitch (and typical a double-update) that we see during the "poke rolling
                         // balls" test.  However, even if we solve this problem we still need to provide a "slerp the visible
                         // proxy toward the true physical position" feature to hide the final glitches in the remote watcher's
                         // simulation.
+
+                        if (entity->getSimulationPriority() < SCRIPT_EDIT_SIMULATION_PRIORITY) {
+                            // we re-assert our simulation ownership at a higher priority
+                            properties.setSimulationOwner(myNodeID, 
+                                    glm::max(entity->getSimulationPriority(), SCRIPT_EDIT_SIMULATION_PRIORITY));
+                        }
+                    } else {
+                        // we make a bid for simulation ownership
+                        properties.setSimulationOwner(myNodeID, SCRIPT_EDIT_SIMULATION_PRIORITY);
+                        entity->flagForOwnership();
                     }
-                    // we make a bid for (or assert existing) simulation ownership
-                    properties.setSimulatorID(myNodeID);
                 }
                 entity->setLastBroadcast(usecTimestampNow());
             }
@@ -567,6 +575,11 @@ QUuid EntityScriptingInterface::addAction(const QString& actionTypeString,
                 return false;
             }
             if (actionFactory->factory(simulation, actionType, actionID, entity, arguments)) {
+                auto nodeList = DependencyManager::get<NodeList>();
+                const QUuid myNodeID = nodeList->getSessionUUID();
+                if (entity->getSimulatorID() != myNodeID) {
+                    entity->flagForOwnership();
+                }
                 return true;
             }
             return false;
@@ -580,7 +593,15 @@ QUuid EntityScriptingInterface::addAction(const QString& actionTypeString,
 
 bool EntityScriptingInterface::updateAction(const QUuid& entityID, const QUuid& actionID, const QVariantMap& arguments) {
     return actionWorker(entityID, [&](EntitySimulation* simulation, EntityItemPointer entity) {
-            return entity->updateAction(simulation, actionID, arguments);
+            bool success = entity->updateAction(simulation, actionID, arguments);
+            if (success) {
+                auto nodeList = DependencyManager::get<NodeList>();
+                const QUuid myNodeID = nodeList->getSessionUUID();
+                if (entity->getSimulatorID() != myNodeID) {
+                    entity->flagForOwnership();
+                }
+            }
+            return success;
         });
 }
 
diff --git a/libraries/entities/src/EntityTree.cpp b/libraries/entities/src/EntityTree.cpp
index 752082932b..3d5878784a 100644
--- a/libraries/entities/src/EntityTree.cpp
+++ b/libraries/entities/src/EntityTree.cpp
@@ -150,23 +150,34 @@ bool EntityTree::updateEntityWithElement(EntityItemPointer entity, const EntityI
     } else {
         if (getIsServer()) {
             bool simulationBlocked = !entity->getSimulatorID().isNull();
-            if (properties.simulatorIDChanged()) {
-                QUuid submittedID = properties.getSimulatorID();
+            if (properties.simulationOwnerChanged()) {
+                QUuid submittedID = properties.getSimulationOwner().getID();
                 // a legit interface will only submit their own ID or NULL:
                 if (submittedID.isNull()) {
                     if (entity->getSimulatorID() == senderID) {
                         // We only allow the simulation owner to clear their own simulationID's.
                         simulationBlocked = false;
+                        properties.clearSimulationOwner(); // clear everything
                     }
                     // else: We assume the sender really did believe it was the simulation owner when it sent
                 } else if (submittedID == senderID) {
                     // the sender is trying to take or continue ownership
-                    if (entity->getSimulatorID().isNull() || entity->getSimulatorID() == senderID) {
+                    if (entity->getSimulatorID().isNull()) {
+                        // the sender it taking ownership
+                        properties.promoteSimulationPriority(RECRUIT_SIMULATION_PRIORITY);
+                        simulationBlocked = false;
+                    } else if (entity->getSimulatorID() == senderID) {
+                        // the sender is asserting ownership
                         simulationBlocked = false;
                     } else {
                         // the sender is trying to steal ownership from another simulator
-                        // so we apply the ownership change filter
-                        if (usecTimestampNow() - entity->getSimulatorIDChangedTime() > SIMULATOR_CHANGE_LOCKOUT_PERIOD) {
+                        // so we apply the rules for ownership change:
+                        // (1) higher priority wins
+                        // (2) equal priority wins if ownership filter has expired except...
+                        uint8_t oldPriority = entity->getSimulationPriority();
+                        uint8_t newPriority = properties.getSimulationOwner().getPriority();
+                        if (newPriority > oldPriority || 
+                             (newPriority == oldPriority && properties.getSimulationOwner().hasExpired())) {
                             simulationBlocked = false;
                         }
                     }
@@ -174,12 +185,17 @@ bool EntityTree::updateEntityWithElement(EntityItemPointer entity, const EntityI
                     // the entire update is suspect --> ignore it
                     return false;
                 }
+            } else {
+                simulationBlocked = senderID != entity->getSimulatorID();
             }
             if (simulationBlocked) {
-                // squash the physics-related changes.
-                properties.setSimulatorIDChanged(false);
+                // squash ownership and physics-related changes.
+                properties.setSimulationOwnerChanged(false);
                 properties.setPositionChanged(false);
                 properties.setRotationChanged(false);
+                properties.setVelocityChanged(false);
+                properties.setAngularVelocityChanged(false);
+                properties.setAccelerationChanged(false);
             }
         }
         // else client accepts what the server says
diff --git a/libraries/entities/src/SimpleEntitySimulation.cpp b/libraries/entities/src/SimpleEntitySimulation.cpp
index 0d1eda1ac8..c9d4fdb2f6 100644
--- a/libraries/entities/src/SimpleEntitySimulation.cpp
+++ b/libraries/entities/src/SimpleEntitySimulation.cpp
@@ -23,19 +23,20 @@ void SimpleEntitySimulation::updateEntitiesInternal(const quint64& now) {
     // has finished simulating it.
     auto nodeList = DependencyManager::get<LimitedNodeList>();
 
-    SetOfEntities::iterator itemItr = _hasSimulationOwnerEntities.begin();
-    while (itemItr != _hasSimulationOwnerEntities.end()) {
+    SetOfEntities::iterator itemItr = _entitiesWithSimulator.begin();
+    while (itemItr != _entitiesWithSimulator.end()) {
         EntityItemPointer entity = *itemItr;
         if (entity->getSimulatorID().isNull()) {
-            itemItr = _hasSimulationOwnerEntities.erase(itemItr);
+            itemItr = _entitiesWithSimulator.erase(itemItr);
         } else if (now - entity->getLastChangedOnServer() >= AUTO_REMOVE_SIMULATION_OWNER_USEC) {
             SharedNodePointer ownerNode = nodeList->nodeWithUUID(entity->getSimulatorID());
             if (ownerNode.isNull() || !ownerNode->isAlive()) {
                 qCDebug(entities) << "auto-removing simulation owner" << entity->getSimulatorID();
-
                 entity->setSimulatorID(QUuid());
                 itemItr = _hasSimulationOwnerEntities.erase(itemItr);
-
+                // TODO: zero velocities when we clear simulatorID?
+                entity->clearSimulationOwnership();
+                itemItr = _entitiesWithSimulator.erase(itemItr);
                 // zero the velocity on this entity so that it doesn't drift far away
                 entity->setVelocity(glm::vec3(0.0f));
             } else {
@@ -50,23 +51,23 @@ void SimpleEntitySimulation::updateEntitiesInternal(const quint64& now) {
 void SimpleEntitySimulation::addEntityInternal(EntityItemPointer entity) {
     EntitySimulation::addEntityInternal(entity);
     if (!entity->getSimulatorID().isNull()) {
-        _hasSimulationOwnerEntities.insert(entity);
+        _entitiesWithSimulator.insert(entity);
     }
 }
 
 void SimpleEntitySimulation::removeEntityInternal(EntityItemPointer entity) {
-    _hasSimulationOwnerEntities.remove(entity);
+    _entitiesWithSimulator.remove(entity);
 }
 
 void SimpleEntitySimulation::changeEntityInternal(EntityItemPointer entity) {
     EntitySimulation::changeEntityInternal(entity);
     if (!entity->getSimulatorID().isNull()) {
-        _hasSimulationOwnerEntities.insert(entity);
+        _entitiesWithSimulator.insert(entity);
     }
     entity->clearDirtyFlags();
 }
 
 void SimpleEntitySimulation::clearEntitiesInternal() {
-    _hasSimulationOwnerEntities.clear();
+    _entitiesWithSimulator.clear();
 }
 
diff --git a/libraries/entities/src/SimpleEntitySimulation.h b/libraries/entities/src/SimpleEntitySimulation.h
index 6eb3980dd3..fff0659067 100644
--- a/libraries/entities/src/SimpleEntitySimulation.h
+++ b/libraries/entities/src/SimpleEntitySimulation.h
@@ -28,7 +28,7 @@ protected:
     virtual void changeEntityInternal(EntityItemPointer entity);
     virtual void clearEntitiesInternal();
 
-    SetOfEntities _hasSimulationOwnerEntities;
+    SetOfEntities _entitiesWithSimulator;
 };
 
 #endif // hifi_SimpleEntitySimulation_h
diff --git a/libraries/entities/src/SimulationOwner.cpp b/libraries/entities/src/SimulationOwner.cpp
new file mode 100644
index 0000000000..d6957873e2
--- /dev/null
+++ b/libraries/entities/src/SimulationOwner.cpp
@@ -0,0 +1,181 @@
+//
+//  SimulationOwner.cpp
+//  libraries/entities/src
+//
+//  Created by Andrew Meadows on 2015.06.19
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "SimulationOwner.h"
+
+#include <iostream> // included for tests
+#include <assert.h>
+
+#include <NumericalConstants.h>
+
+// static 
+const int SimulationOwner::NUM_BYTES_ENCODED = NUM_BYTES_RFC4122_UUID + 1;
+
+
+SimulationOwner::SimulationOwner(const SimulationOwner& other) 
+    : _id(other._id), _priority(other._priority), _expiry(other._expiry) {
+}
+
+QByteArray SimulationOwner::toByteArray() const {
+    QByteArray data = _id.toRfc4122();
+    data.append(_priority);
+    return data;
+}
+
+bool SimulationOwner::fromByteArray(const QByteArray& data) {
+    if (data.size() == NUM_BYTES_ENCODED) {
+        QByteArray idBytes = data.left(NUM_BYTES_RFC4122_UUID);
+        _id = QUuid::fromRfc4122(idBytes);
+        _priority = data[NUM_BYTES_RFC4122_UUID];
+        return true;
+    }
+    return false;
+}
+
+void SimulationOwner::clear() {
+    _id = QUuid();
+    _priority = 0;
+    _expiry = 0;
+}
+
+void SimulationOwner::setPriority(quint8 priority) {
+    _priority = priority;
+    if (_priority == 0) {
+        // when priority is zero we clear everything
+        _expiry = 0;
+        _id = QUuid();
+    }
+}
+
+void SimulationOwner::promotePriority(quint8 priority) {
+    if (priority > _priority) {
+        _priority = priority;
+        updateExpiry();
+    }
+}
+
+bool SimulationOwner::setID(const QUuid& id) {
+    if (_id != id) {
+        _id = id;
+        updateExpiry();
+        if (_id.isNull()) {
+            _priority = 0;
+        }
+        return true;
+    }
+    return false;
+}
+
+bool SimulationOwner::set(const QUuid& id, quint8 priority) {
+    setPriority(priority);
+    return setID(id);
+}
+
+bool SimulationOwner::set(const SimulationOwner& owner) {
+    setPriority(owner._priority);
+    return setID(owner._id);
+}
+
+void SimulationOwner::updateExpiry() {
+    const quint64 OWNERSHIP_LOCKOUT_EXPIRY = USECS_PER_SECOND / 5;
+    _expiry = usecTimestampNow() + OWNERSHIP_LOCKOUT_EXPIRY;
+}
+
+// NOTE: eventually this code will be moved into unit tests
+// static debug
+void SimulationOwner::test() {
+    { // test default constructor
+        SimulationOwner simOwner;
+        if (!simOwner.isNull()) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner should be NULL" << std::endl;
+        }
+
+        if (simOwner.getPriority() != 0) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : unexpeced SimulationOwner priority" << std::endl;
+        }
+    }
+
+    { // test set constructor
+        QUuid id = QUuid::createUuid();
+        quint8 priority = 128;
+        SimulationOwner simOwner(id, priority);
+        if (simOwner.isNull()) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner should NOT be NULL" << std::endl;
+        }
+
+        if (simOwner.getID() != id) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner with unexpected id" << std::endl;
+        }
+
+        if (simOwner.getPriority() != priority) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : unexpeced SimulationOwner priority" << std::endl;
+        }
+
+        QUuid otherID = QUuid::createUuid();
+        if (simOwner.getID() == otherID) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner with unexpected id" << std::endl;
+        }
+    }
+
+    { // test set()
+        QUuid id = QUuid::createUuid();
+        quint8 priority = 1;
+        SimulationOwner simOwner;
+        simOwner.set(id, priority);
+        if (simOwner.isNull()) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner should NOT be NULL" << std::endl;
+        }
+
+        if (simOwner.getID() != id) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : SimulationOwner with unexpected id" << std::endl;
+        }
+
+        if (simOwner.getPriority() != priority) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : unexpeced SimulationOwner priority" << std::endl;
+        }
+    }
+
+    { // test encode/decode
+        SimulationOwner ownerA(QUuid::createUuid(), 1);
+        SimulationOwner ownerB(QUuid::createUuid(), 2);
+
+        QByteArray data = ownerA.toByteArray();
+        ownerB.fromByteArray(data);
+
+        if (ownerA.getID() != ownerB.getID()) {
+            std::cout << __FILE__ << ":" << __LINE__ << " ERROR : ownerA._id should be equal to ownerB._id" << std::endl;
+        }
+    }
+}
+
+bool SimulationOwner::operator!=(const SimulationOwner& other) {
+    return (_id != other._id && _priority != other._priority);
+}
+
+SimulationOwner& SimulationOwner::operator=(const SimulationOwner& other) {
+    _priority = other._priority;
+    if (_priority == 0) {
+        _id = QUuid();
+        _expiry = 0;
+    } else {
+        if (_id != other._id) {
+            updateExpiry();
+        }
+        _id = other._id;
+    }
+    return *this;
+}
+
+QDebug& operator<<(QDebug& d, const SimulationOwner& simOwner) {
+    d << "{ id : " << simOwner._id << ", priority : " << (int)simOwner._priority << " }";
+    return d;
+}
+
diff --git a/libraries/entities/src/SimulationOwner.h b/libraries/entities/src/SimulationOwner.h
new file mode 100644
index 0000000000..325be54e62
--- /dev/null
+++ b/libraries/entities/src/SimulationOwner.h
@@ -0,0 +1,86 @@
+//
+//  SimulationOwner.h
+//  libraries/entities/src
+//
+//  Created by Andrew Meadows on 2015.06.19
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_SimulationOwner_h
+#define hifi_SimulationOwner_h
+
+#include <QtCore/QDebug>
+#include <QtCore/QByteArray>
+
+#include <SharedUtil.h>
+#include <UUID.h>
+
+// Simulation observers will bid to simulate unowned active objects at the lowest possible priority
+// which is VOLUNTEER.  If the server accepts a VOLUNTEER bid it will automatically bump it 
+// to RECRUIT priority so that other volunteers don't accidentally take over.
+const quint8 VOLUNTEER_SIMULATION_PRIORITY = 0x01;
+const quint8 RECRUIT_SIMULATION_PRIORITY = VOLUNTEER_SIMULATION_PRIORITY + 1;
+
+// When poking objects with scripts an observer will bid at SCRIPT_EDIT priority.
+const quint8 SCRIPT_EDIT_SIMULATION_PRIORITY = 0x80;
+
+// PERSONAL priority (needs a better name) is the level at which a simulation observer will bid for
+// objects that collide its MyAvatar.
+const quint8 PERSONAL_SIMULATION_PRIORITY = SCRIPT_EDIT_SIMULATION_PRIORITY - 1;
+
+
+class SimulationOwner {
+public:
+    static const int NUM_BYTES_ENCODED;
+
+    SimulationOwner() : _id(), _priority(0), _expiry(0) {}
+    SimulationOwner(const QUuid& id, quint8 priority) : _id(id), _priority(priority), _expiry(0) {}
+    SimulationOwner(const SimulationOwner& other);
+
+    const QUuid& getID() const { return _id; }
+    quint8 getPriority() const { return _priority; }
+    const quint64& getExpiry() const { return _expiry; }
+
+    QByteArray toByteArray() const;
+    bool fromByteArray(const QByteArray& data);
+
+    void clear();
+
+    void setPriority(quint8 priority);
+    void promotePriority(quint8 priority);
+
+    // return true if id is changed
+    bool setID(const QUuid& id);
+    bool set(const QUuid& id, quint8 priority);
+    bool set(const SimulationOwner& owner);
+
+    bool isNull() const { return _id.isNull(); }
+    bool matchesValidID(const QUuid& id) const { return _id == id && !_id.isNull(); }
+
+    void updateExpiry();
+
+    bool hasExpired() const { return usecTimestampNow() > _expiry; }
+
+    bool operator>=(quint8 priority) const { return _priority >= priority; }
+    bool operator==(const SimulationOwner& other) { return (_id == other._id && _priority == other._priority); }
+
+    bool operator!=(const SimulationOwner& other);
+    SimulationOwner& operator=(const SimulationOwner& other);
+
+    friend QDebug& operator<<(QDebug& d, const SimulationOwner& simOwner);
+
+    // debug
+    static void test();
+
+private:
+    QUuid _id;
+    quint8 _priority;
+    quint64 _expiry;
+};
+
+
+
+#endif // hifi_SimulationOwner_h
diff --git a/libraries/networking/src/PacketHeaders.cpp b/libraries/networking/src/PacketHeaders.cpp
index fab9ca7070..1a579cb6c9 100644
--- a/libraries/networking/src/PacketHeaders.cpp
+++ b/libraries/networking/src/PacketHeaders.cpp
@@ -73,7 +73,7 @@ PacketVersion versionForPacketType(PacketType packetType) {
         case PacketTypeEntityAdd:
         case PacketTypeEntityEdit:
         case PacketTypeEntityData:
-            return VERSION_ACTIONS_OVER_WIRE;
+            return VERSION_ENTITIES_HAVE_SIMULATION_OWNER;
         case PacketTypeEntityErase:
             return 2;
         case PacketTypeAudioStreamStats:
diff --git a/libraries/networking/src/PacketHeaders.h b/libraries/networking/src/PacketHeaders.h
index 5d6e9d7c83..e30daac328 100644
--- a/libraries/networking/src/PacketHeaders.h
+++ b/libraries/networking/src/PacketHeaders.h
@@ -187,5 +187,6 @@ const PacketVersion VERSION_ENTITIES_FACE_CAMERA = 30;
 const PacketVersion VERSION_ENTITIES_SCRIPT_TIMESTAMP = 31;
 const PacketVersion VERSION_ENTITIES_SCRIPT_TIMESTAMP_FIX = 32;
 const PacketVersion VERSION_ACTIONS_OVER_WIRE = 33;
+const PacketVersion VERSION_ENTITIES_HAVE_SIMULATION_OWNER = 34;
 
 #endif // hifi_PacketHeaders_h
diff --git a/libraries/octree/src/OctreePacketData.h b/libraries/octree/src/OctreePacketData.h
index 9476fe024e..e6f86bb861 100644
--- a/libraries/octree/src/OctreePacketData.h
+++ b/libraries/octree/src/OctreePacketData.h
@@ -247,7 +247,6 @@ public:
     static int unpackDataFromBytes(const unsigned char* dataBytes, QVector<glm::vec3>& result);
     static int unpackDataFromBytes(const unsigned char* dataBytes, QByteArray& result);
 
-
 private:
     /// appends raw bytes, might fail if byte would cause packet to be too large
     bool append(const unsigned char* data, int length);
diff --git a/libraries/physics/src/EntityMotionState.cpp b/libraries/physics/src/EntityMotionState.cpp
index b6b8a2787c..d04d190145 100644
--- a/libraries/physics/src/EntityMotionState.cpp
+++ b/libraries/physics/src/EntityMotionState.cpp
@@ -26,6 +26,9 @@
 static const float ACCELERATION_EQUIVALENT_EPSILON_RATIO = 0.1f;
 static const quint8 STEPS_TO_DECIDE_BALLISTIC = 4;
 
+const uint32_t LOOPS_FOR_SIMULATION_ORPHAN = 50;
+//const uint32_t LOOPS_BETWEEN_OWNERSHIP_BIDS = 30;
+const quint64 USECS_BETWEEN_OWNERSHIP_BIDS = USECS_PER_SECOND / 5;
 
 #ifdef WANT_DEBUG_ENTITY_TREE_LOCKS
 bool EntityMotionState::entityTreeIsLocked() const {
@@ -58,8 +61,7 @@ bool entityTreeIsLocked() {
 EntityMotionState::EntityMotionState(btCollisionShape* shape, EntityItemPointer entity) :
     ObjectMotionState(shape),
     _entity(entity),
-    _sentActive(false),
-    _numNonMovingUpdates(0),
+    _sentInactive(true),
     _lastStep(0),
     _serverPosition(0.0f),
     _serverRotation(),
@@ -72,8 +74,7 @@ EntityMotionState::EntityMotionState(btCollisionShape* shape, EntityItemPointer
     _measuredAcceleration(glm::vec3(0.0f)),
     _measuredDeltaTime(0.0f),
     _accelerationNearlyGravityCount(0),
-    _candidateForOwnership(false),
-    _loopsSinceOwnershipBid(0),
+    _nextOwnershipBid(0),
     _loopsWithoutOwner(0)
 {
     _type = MOTIONSTATE_TYPE_ENTITY;
@@ -97,28 +98,35 @@ void EntityMotionState::updateServerPhysicsVariables() {
 }
 
 // virtual
-void EntityMotionState::handleEasyChanges(uint32_t flags) {
+void EntityMotionState::handleEasyChanges(uint32_t flags, PhysicsEngine* engine) {
     assert(entityTreeIsLocked());
     updateServerPhysicsVariables();
-    ObjectMotionState::handleEasyChanges(flags);
+    ObjectMotionState::handleEasyChanges(flags, engine);
+
     if (flags & EntityItem::DIRTY_SIMULATOR_ID) {
         _loopsWithoutOwner = 0;
-        _candidateForOwnership = 0;
-        if (_entity->getSimulatorID().isNull()
-                && !_entity->isMoving()
-                && _body->isActive()) {
+        if (_entity->getSimulatorID().isNull()) {
+            // simulation ownership is being removed
             // remove the ACTIVATION flag because this object is coming to rest
             // according to a remote simulation and we don't want to wake it up again
             flags &= ~EntityItem::DIRTY_PHYSICS_ACTIVATION;
+            // hint to Bullet that the object is deactivating
             _body->setActivationState(WANTS_DEACTIVATION);
-        } else {
-            auto nodeList = DependencyManager::get<NodeList>();
-            const QUuid& sessionID = nodeList->getSessionUUID();
-            if (_entity->getSimulatorID() != sessionID) {
-                _loopsSinceOwnershipBid = 0;
+            _outgoingPriority = 0;
+        } else  {
+            _nextOwnershipBid = usecTimestampNow() + USECS_BETWEEN_OWNERSHIP_BIDS;
+            if (engine->getSessionID() == _entity->getSimulatorID() || _entity->getSimulationPriority() > _outgoingPriority) {
+                // we own the simulation or our priority looses to remote
+                _outgoingPriority = 0;
             }
         }
     }
+    if (flags & EntityItem::DIRTY_SIMULATOR_OWNERSHIP) {
+        // (DIRTY_SIMULATOR_OWNERSHIP really means "we should bid for ownership with SCRIPT priority")
+        // we're manipulating this object directly via script, so we artificially 
+        // manipulate the logic to trigger an immediate bid for ownership
+        setOutgoingPriority(SCRIPT_EDIT_SIMULATION_PRIORITY);
+    }
     if ((flags & EntityItem::DIRTY_PHYSICS_ACTIVATION) && !_body->isActive()) {
         _body->activate();
     }
@@ -195,13 +203,10 @@ void EntityMotionState::setWorldTransform(const btTransform& worldTrans) {
     if (_entity->getSimulatorID().isNull()) {
         _loopsWithoutOwner++;
 
-        const uint32_t OWNERSHIP_BID_DELAY = 50;
-        if (_loopsWithoutOwner > OWNERSHIP_BID_DELAY) {
+        if (_loopsWithoutOwner > LOOPS_FOR_SIMULATION_ORPHAN && usecTimestampNow() > _nextOwnershipBid) {
             //qDebug() << "Warning -- claiming something I saw moving." << getName();
-            _candidateForOwnership = true;
+            setOutgoingPriority(VOLUNTEER_SIMULATION_PRIORITY);
         }
-    } else {
-        _loopsWithoutOwner = 0;
     }
 
     #ifdef WANT_DEBUG
@@ -232,7 +237,7 @@ bool EntityMotionState::isCandidateForOwnership(const QUuid& sessionID) const {
         return false;
     }
     assert(entityTreeIsLocked());
-    return _candidateForOwnership || sessionID == _entity->getSimulatorID();
+    return _outgoingPriority > 0 || sessionID == _entity->getSimulatorID();
 }
 
 bool EntityMotionState::remoteSimulationOutOfSync(uint32_t simulationStep) {
@@ -245,7 +250,7 @@ bool EntityMotionState::remoteSimulationOutOfSync(uint32_t simulationStep) {
         _serverVelocity = bulletToGLM(_body->getLinearVelocity());
         _serverAngularVelocity = bulletToGLM(_body->getAngularVelocity());
         _lastStep = simulationStep;
-        _sentActive = false;
+        _sentInactive = true;
         return false;
     }
 
@@ -259,7 +264,7 @@ bool EntityMotionState::remoteSimulationOutOfSync(uint32_t simulationStep) {
     float dt = (float)(numSteps) * PHYSICS_ENGINE_FIXED_SUBSTEP;
 
     const float INACTIVE_UPDATE_PERIOD = 0.5f;
-    if (!_sentActive) {
+    if (_sentInactive) {
         // we resend the inactive update every INACTIVE_UPDATE_PERIOD
         // until it is removed from the outgoing updates
         // (which happens when we don't own the simulation and it isn't touching our simulation)
@@ -347,30 +352,20 @@ bool EntityMotionState::shouldSendUpdate(uint32_t simulationStep, const QUuid& s
     assert(_body);
     assert(entityTreeIsLocked());
 
-    if (!remoteSimulationOutOfSync(simulationStep)) {
-        _candidateForOwnership = false;
-        return false;
-    }
-
-    if (_entity->getSimulatorID() == sessionID) {
-        // we own the simulation
-        _candidateForOwnership = false;
-        return true;
-    }
-
-    const uint32_t FRAMES_BETWEEN_OWNERSHIP_CLAIMS = 30;
-    if (_candidateForOwnership) {
-        _candidateForOwnership = false;
-        ++_loopsSinceOwnershipBid;
-        if (_loopsSinceOwnershipBid > FRAMES_BETWEEN_OWNERSHIP_CLAIMS) {
-            // we don't own the simulation, but it's time to bid for it
-            _loopsSinceOwnershipBid = 0;
-            return true;
+    if (_entity->getSimulatorID() != sessionID) {
+        // we don't own the simulation, but maybe we should...
+        if (_outgoingPriority > 0) {
+            if (_outgoingPriority < _entity->getSimulationPriority()) {
+                // our priority looses to remote, so we don't bother to bid
+                _outgoingPriority = 0;
+                return false;
+            }
+            return usecTimestampNow() > _nextOwnershipBid;
         }
-    }
-
-    _candidateForOwnership = false;
-    return false;
+        return false;
+    } 
+   
+    return remoteSimulationOutOfSync(simulationStep);
 }
 
 void EntityMotionState::sendUpdate(OctreeEditPacketSender* packetSender, const QUuid& sessionID, uint32_t step) {
@@ -384,7 +379,7 @@ void EntityMotionState::sendUpdate(OctreeEditPacketSender* packetSender, const Q
         _entity->setVelocity(zero);
         _entity->setAngularVelocity(zero);
         _entity->setAcceleration(zero);
-        _sentActive = false;
+        _sentInactive = true;
     } else {
         float gravityLength = glm::length(_entity->getGravity());
         float accVsGravity = glm::abs(glm::length(_measuredAcceleration) - gravityLength);
@@ -421,7 +416,7 @@ void EntityMotionState::sendUpdate(OctreeEditPacketSender* packetSender, const Q
             _entity->setVelocity(zero);
             _entity->setAngularVelocity(zero);
         }
-        _sentActive = true;
+        _sentInactive = false;
     }
 
     // remember properties for local server prediction
@@ -431,7 +426,7 @@ void EntityMotionState::sendUpdate(OctreeEditPacketSender* packetSender, const Q
     _serverAcceleration = _entity->getAcceleration();
     _serverAngularVelocity = _entity->getAngularVelocity();
 
-    EntityItemProperties properties = _entity->getProperties();
+    EntityItemProperties properties;
 
     // explicitly set the properties that changed so that they will be packed
     properties.setPosition(_serverPosition);
@@ -457,14 +452,14 @@ void EntityMotionState::sendUpdate(OctreeEditPacketSender* packetSender, const Q
         if (!active) {
             // we own the simulation but the entity has stopped, so we tell the server that we're clearing simulatorID
             // but we remember that we do still own it...  and rely on the server to tell us that we don't
-            properties.setSimulatorID(QUuid());
-        } else {
-            // explicitly set the property's simulatorID so that it is flagged as changed and will be packed
-            properties.setSimulatorID(sessionID);
+            properties.clearSimulationOwner();
+            _outgoingPriority = 0;
         }
+        // else the ownership is not changing so we don't bother to pack it
     } else {
         // we don't own the simulation for this entity yet, but we're sending a bid for it
-        properties.setSimulatorID(sessionID);
+        properties.setSimulationOwner(sessionID, glm::max<quint8>(_outgoingPriority, VOLUNTEER_SIMULATION_PRIORITY));
+        _nextOwnershipBid = now + USECS_BETWEEN_OWNERSHIP_BIDS;
     }
 
     if (EntityItem::getSendPhysicsUpdates()) {
@@ -502,6 +497,13 @@ uint32_t EntityMotionState::getAndClearIncomingDirtyFlags() {
     return dirtyFlags;
 }
 
+// virtual 
+quint8 EntityMotionState::getSimulationPriority() const {
+    if (_entity) {
+        return _entity->getSimulationPriority();
+    }
+    return 0;
+}
 
 // virtual
 QUuid EntityMotionState::getSimulatorID() const {
@@ -512,10 +514,11 @@ QUuid EntityMotionState::getSimulatorID() const {
     return QUuid();
 }
 
-
 // virtual
-void EntityMotionState::bump() {
-    _candidateForOwnership = true;
+void EntityMotionState::bump(quint8 priority) {
+    if (_entity) {
+        setOutgoingPriority(glm::max(VOLUNTEER_SIMULATION_PRIORITY, --priority));
+    }
 }
 
 void EntityMotionState::resetMeasuredBodyAcceleration() {
@@ -543,9 +546,10 @@ void EntityMotionState::measureBodyAcceleration() {
         glm::vec3 velocity = bulletToGLM(_body->getLinearVelocity());
         _measuredAcceleration = (velocity / powf(1.0f - _body->getLinearDamping(), dt) - _lastVelocity) * invDt;
         _lastVelocity = velocity;
-        if (numSubsteps > PHYSICS_ENGINE_MAX_NUM_SUBSTEPS && !_candidateForOwnership) {
-            _loopsSinceOwnershipBid = 0;
+        if (numSubsteps > PHYSICS_ENGINE_MAX_NUM_SUBSTEPS) {
             _loopsWithoutOwner = 0;
+            _lastStep = ObjectMotionState::getWorldSimulationStep();
+            _sentInactive = false;
         }
     }
 }
@@ -584,3 +588,7 @@ int16_t EntityMotionState::computeCollisionGroup() {
     }
     return COLLISION_GROUP_DEFAULT;
 }
+
+void EntityMotionState::setOutgoingPriority(quint8 priority) {
+    _outgoingPriority = glm::max<quint8>(_outgoingPriority, priority);
+}
diff --git a/libraries/physics/src/EntityMotionState.h b/libraries/physics/src/EntityMotionState.h
index 4f777a4575..9f7bafd416 100644
--- a/libraries/physics/src/EntityMotionState.h
+++ b/libraries/physics/src/EntityMotionState.h
@@ -29,7 +29,7 @@ public:
     virtual ~EntityMotionState();
 
     void updateServerPhysicsVariables();
-    virtual void handleEasyChanges(uint32_t flags);
+    virtual void handleEasyChanges(uint32_t flags, PhysicsEngine* engine);
     virtual void handleHardAndEasyChanges(uint32_t flags, PhysicsEngine* engine);
 
     /// \return MOTION_TYPE_DYNAMIC or MOTION_TYPE_STATIC based on params set in EntityItem
@@ -68,8 +68,9 @@ public:
 
     virtual const QUuid& getObjectID() const { return _entity->getID(); }
 
+    virtual quint8 getSimulationPriority() const;
     virtual QUuid getSimulatorID() const;
-    virtual void bump();
+    virtual void bump(quint8 priority);
 
     EntityItemPointer getEntity() const { return _entity; }
 
@@ -80,6 +81,9 @@ public:
 
     virtual int16_t computeCollisionGroup();
 
+    // eternal logic can suggest a simuator priority bid for the next outgoing update
+    void setOutgoingPriority(quint8 priority);
+
     friend class PhysicalEntitySimulation;
 
 protected:
@@ -93,8 +97,7 @@ protected:
 
     EntityItemPointer _entity;
 
-    bool _sentActive;   // true if body was active when we sent last update
-    int _numNonMovingUpdates; // RELIABLE_SEND_HACK for "not so reliable" resends of packets for non-moving objects
+    bool _sentInactive;   // true if body was inactive when we sent last update
 
     // these are for the prediction of the remote server's simple extrapolation
     uint32_t _lastStep; // last step of server extrapolation
@@ -111,9 +114,9 @@ protected:
     float _measuredDeltaTime;
 
     quint8 _accelerationNearlyGravityCount;
-    bool _candidateForOwnership;
-    uint32_t _loopsSinceOwnershipBid;
+    quint64 _nextOwnershipBid = 0;
     uint32_t _loopsWithoutOwner;
+    quint8 _outgoingPriority = 0;
 };
 
 #endif // hifi_EntityMotionState_h
diff --git a/libraries/physics/src/ObjectMotionState.cpp b/libraries/physics/src/ObjectMotionState.cpp
index 85e67d72f7..7ff119fb79 100644
--- a/libraries/physics/src/ObjectMotionState.cpp
+++ b/libraries/physics/src/ObjectMotionState.cpp
@@ -114,7 +114,7 @@ void ObjectMotionState::setRigidBody(btRigidBody* body) {
     }
 }
 
-void ObjectMotionState::handleEasyChanges(uint32_t flags) {
+void ObjectMotionState::handleEasyChanges(uint32_t flags, PhysicsEngine* engine) {
     if (flags & EntityItem::DIRTY_POSITION) {
         btTransform worldTrans;
         if (flags & EntityItem::DIRTY_ROTATION) {
@@ -159,7 +159,7 @@ void ObjectMotionState::handleHardAndEasyChanges(uint32_t flags, PhysicsEngine*
             if ((flags & HARD_DIRTY_PHYSICS_FLAGS) == 0) {
                 // no HARD flags remain, so do any EASY changes
                 if (flags & EASY_DIRTY_PHYSICS_FLAGS) {
-                    handleEasyChanges(flags);
+                    handleEasyChanges(flags, engine);
                 }
                 return;
             }
@@ -174,7 +174,7 @@ void ObjectMotionState::handleHardAndEasyChanges(uint32_t flags, PhysicsEngine*
         }
     }
     if (flags & EASY_DIRTY_PHYSICS_FLAGS) {
-        handleEasyChanges(flags);
+        handleEasyChanges(flags, engine);
     }
     // it is possible that there are no HARD flags at this point (if DIRTY_SHAPE was removed)
     // so we check again befoe we reinsert:
diff --git a/libraries/physics/src/ObjectMotionState.h b/libraries/physics/src/ObjectMotionState.h
index 561ce02d62..30394ef5fc 100644
--- a/libraries/physics/src/ObjectMotionState.h
+++ b/libraries/physics/src/ObjectMotionState.h
@@ -40,7 +40,8 @@ enum MotionStateType {
 const uint32_t HARD_DIRTY_PHYSICS_FLAGS = (uint32_t)(EntityItem::DIRTY_MOTION_TYPE | EntityItem::DIRTY_SHAPE);
 const uint32_t EASY_DIRTY_PHYSICS_FLAGS = (uint32_t)(EntityItem::DIRTY_TRANSFORM | EntityItem::DIRTY_VELOCITIES |
                                                      EntityItem::DIRTY_MASS | EntityItem::DIRTY_COLLISION_GROUP |
-                                                     EntityItem::DIRTY_MATERIAL);
+                                                     EntityItem::DIRTY_MATERIAL | EntityItem::DIRTY_SIMULATOR_ID | 
+                                                     EntityItem::DIRTY_SIMULATOR_OWNERSHIP);
 
 // These are the set of incoming flags that the PhysicsEngine needs to hear about:
 const uint32_t DIRTY_PHYSICS_FLAGS = (uint32_t)(HARD_DIRTY_PHYSICS_FLAGS | EASY_DIRTY_PHYSICS_FLAGS |
@@ -70,7 +71,7 @@ public:
     ObjectMotionState(btCollisionShape* shape);
     ~ObjectMotionState();
 
-    virtual void handleEasyChanges(uint32_t flags);
+    virtual void handleEasyChanges(uint32_t flags, PhysicsEngine* engine);
     virtual void handleHardAndEasyChanges(uint32_t flags, PhysicsEngine* engine);
 
     void updateBodyMaterialProperties();
@@ -118,8 +119,9 @@ public:
 
     virtual const QUuid& getObjectID() const = 0;
 
+    virtual quint8 getSimulationPriority() const { return 0; }
     virtual QUuid getSimulatorID() const = 0;
-    virtual void bump() = 0;
+    virtual void bump(quint8 priority) {}
 
     virtual QString getName() { return ""; }
 
diff --git a/libraries/physics/src/PhysicsEngine.cpp b/libraries/physics/src/PhysicsEngine.cpp
index 24baa365ef..f533bba7c5 100644
--- a/libraries/physics/src/PhysicsEngine.cpp
+++ b/libraries/physics/src/PhysicsEngine.cpp
@@ -194,7 +194,7 @@ void PhysicsEngine::changeObjects(VectorOfMotionStates& objects) {
         if (flags & HARD_DIRTY_PHYSICS_FLAGS) {
             object->handleHardAndEasyChanges(flags, this);
         } else if (flags & EASY_DIRTY_PHYSICS_FLAGS) {
-            object->handleEasyChanges(flags);
+            object->handleEasyChanges(flags, this);
         }
     }
 }
@@ -260,9 +260,6 @@ void PhysicsEngine::stepSimulation() {
 
 void PhysicsEngine::doOwnershipInfection(const btCollisionObject* objectA, const btCollisionObject* objectB) {
     BT_PROFILE("ownershipInfection");
-    if (_sessionID.isNull()) {
-        return;
-    }
 
     const btCollisionObject* characterObject = _characterController ? _characterController->getCollisionObject() : nullptr;
 
@@ -272,14 +269,16 @@ void PhysicsEngine::doOwnershipInfection(const btCollisionObject* objectA, const
     if (b && ((a && a->getSimulatorID() == _sessionID && !objectA->isStaticObject()) || (objectA == characterObject))) {
         // NOTE: we might own the simulation of a kinematic object (A) 
         // but we don't claim ownership of kinematic objects (B) based on collisions here.
-        if (!objectB->isStaticOrKinematicObject()) {
-            b->bump();
+        if (!objectB->isStaticOrKinematicObject() && b->getSimulatorID() != _sessionID) {
+            quint8 priority = a ? a->getSimulationPriority() : PERSONAL_SIMULATION_PRIORITY;
+            b->bump(priority);
         }
     } else if (a && ((b && b->getSimulatorID() == _sessionID && !objectB->isStaticObject()) || (objectB == characterObject))) {
         // SIMILARLY: we might own the simulation of a kinematic object (B) 
         // but we don't claim ownership of kinematic objects (A) based on collisions here.
-        if (!objectA->isStaticOrKinematicObject()) {
-            a->bump();
+        if (!objectA->isStaticOrKinematicObject() && a->getSimulatorID() != _sessionID) {
+            quint8 priority = b ? b->getSimulationPriority() : PERSONAL_SIMULATION_PRIORITY;
+            a->bump(priority);
         }
     }
 }
@@ -311,7 +310,9 @@ void PhysicsEngine::updateContactMap() {
                 _contactMap[ContactKey(a, b)].update(_numContactFrames, contactManifold->getContactPoint(0));
             }
 
-            doOwnershipInfection(objectA, objectB);
+            if (!_sessionID.isNull()) {
+                doOwnershipInfection(objectA, objectB);
+            }
         }
     }
 }
@@ -402,7 +403,7 @@ void PhysicsEngine::bump(ObjectMotionState* motionState) {
                 if (!objectA->isStaticOrKinematicObject()) {
                     ObjectMotionState* motionStateA = static_cast<ObjectMotionState*>(objectA->getUserPointer());
                     if (motionStateA) {
-                        motionStateA->bump();
+                        motionStateA->bump(VOLUNTEER_SIMULATION_PRIORITY);
                         objectA->setActivationState(ACTIVE_TAG);
                     }
                 }
@@ -410,7 +411,7 @@ void PhysicsEngine::bump(ObjectMotionState* motionState) {
                 if (!objectB->isStaticOrKinematicObject()) {
                     ObjectMotionState* motionStateB = static_cast<ObjectMotionState*>(objectB->getUserPointer());
                     if (motionStateB) {
-                        motionStateB->bump();
+                        motionStateB->bump(VOLUNTEER_SIMULATION_PRIORITY);
                         objectB->setActivationState(ACTIVE_TAG);
                     }
                 }
diff --git a/libraries/shared/src/PhysicsHelpers.h b/libraries/shared/src/PhysicsHelpers.h
index 0e58ae99f0..7ceafea915 100644
--- a/libraries/shared/src/PhysicsHelpers.h
+++ b/libraries/shared/src/PhysicsHelpers.h
@@ -15,7 +15,7 @@
 #include <glm/glm.hpp>
 #include <glm/gtc/quaternion.hpp>
 
-const int PHYSICS_ENGINE_MAX_NUM_SUBSTEPS = 4;
+const int PHYSICS_ENGINE_MAX_NUM_SUBSTEPS = 6; // Bullet will start to "lose time" at 10 FPS.
 const float PHYSICS_ENGINE_FIXED_SUBSTEP = 1.0f / 60.0f;
 
 // return incremental rotation (Bullet-style) caused by angularVelocity over timeStep
diff --git a/libraries/shared/src/StreamUtils.cpp b/libraries/shared/src/StreamUtils.cpp
index b2ea5d95a4..5726728f30 100644
--- a/libraries/shared/src/StreamUtils.cpp
+++ b/libraries/shared/src/StreamUtils.cpp
@@ -15,9 +15,9 @@
 
 #include "StreamUtils.h"
 
-const char* hex_digits = "0123456789abcdef";
 
 void StreamUtil::dump(std::ostream& s, const QByteArray& buffer) {
+    const char* hex_digits = "0123456789abcdef";
     int row_size = 32;
     int i = 0;
     while (i < buffer.size()) {