diff --git a/apps/openmw/mwclass/activator.cpp b/apps/openmw/mwclass/activator.cpp
index 8b41eec13..1ca1150df 100644
--- a/apps/openmw/mwclass/activator.cpp
+++ b/apps/openmw/mwclass/activator.cpp
@@ -58,10 +58,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Activator::getName (const MWWorld::Ptr& ptr) const
+    std::string Activator::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Activator> *ref =
-            ptr.get<ESM::Activator>();
+        const MWWorld::LiveCellRef<ESM::Activator> *ref = ptr.get<ESM::Activator>();
 
         return ref->mBase->mName;
     }
@@ -89,10 +88,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Activator::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Activator::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Activator> *ref =
-            ptr.get<ESM::Activator>();
+        const MWWorld::LiveCellRef<ESM::Activator> *ref = ptr.get<ESM::Activator>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/activator.hpp b/apps/openmw/mwclass/activator.hpp
index 6280587b1..4e371d8dd 100644
--- a/apps/openmw/mwclass/activator.hpp
+++ b/apps/openmw/mwclass/activator.hpp
@@ -21,14 +21,14 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
diff --git a/apps/openmw/mwclass/apparatus.cpp b/apps/openmw/mwclass/apparatus.cpp
index b4d293cb8..3caf68aae 100644
--- a/apps/openmw/mwclass/apparatus.cpp
+++ b/apps/openmw/mwclass/apparatus.cpp
@@ -50,10 +50,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Apparatus::getName (const MWWorld::Ptr& ptr) const
+    std::string Apparatus::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Apparatus> *ref =
-            ptr.get<ESM::Apparatus>();
+        const MWWorld::LiveCellRef<ESM::Apparatus> *ref = ptr.get<ESM::Apparatus>();
 
         return ref->mBase->mName;
     }
@@ -71,10 +70,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Apparatus::getValue (const MWWorld::Ptr& ptr) const
+    int Apparatus::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Apparatus> *ref =
-            ptr.get<ESM::Apparatus>();
+        const MWWorld::LiveCellRef<ESM::Apparatus> *ref = ptr.get<ESM::Apparatus>();
 
         return ref->mBase->mData.mValue;
     }
@@ -112,10 +110,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Apparatus::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Apparatus::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Apparatus> *ref =
-            ptr.get<ESM::Apparatus>();
+        const MWWorld::LiveCellRef<ESM::Apparatus> *ref = ptr.get<ESM::Apparatus>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/apparatus.hpp b/apps/openmw/mwclass/apparatus.hpp
index 071bf83bd..32b58af07 100644
--- a/apps/openmw/mwclass/apparatus.hpp
+++ b/apps/openmw/mwclass/apparatus.hpp
@@ -23,7 +23,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -34,13 +34,13 @@ namespace MWClass
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
             ///< Return name of the script attached to ptr
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             static void registerSelf();
diff --git a/apps/openmw/mwclass/armor.cpp b/apps/openmw/mwclass/armor.cpp
index e51ea11e0..c9369e1ae 100644
--- a/apps/openmw/mwclass/armor.cpp
+++ b/apps/openmw/mwclass/armor.cpp
@@ -56,10 +56,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Armor::getName (const MWWorld::Ptr& ptr) const
+    std::string Armor::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         return ref->mBase->mName;
     }
@@ -75,10 +74,9 @@ namespace MWClass
         return true;
     }
 
-    int Armor::getItemMaxHealth (const MWWorld::Ptr& ptr) const
+    int Armor::getItemMaxHealth (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         return ref->mBase->mData.mHealth;
     }
@@ -92,8 +90,7 @@ namespace MWClass
 
     std::pair<std::vector<int>, bool> Armor::getEquipmentSlots (const MWWorld::Ptr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         std::vector<int> slots_;
 
@@ -124,10 +121,9 @@ namespace MWClass
         return std::make_pair (slots_, false);
     }
 
-    int Armor::getEquipmentSkill (const MWWorld::Ptr& ptr) const
+    int Armor::getEquipmentSkill (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         std::string typeGmst;
 
@@ -169,10 +165,9 @@ namespace MWClass
             return ESM::Skill::HeavyArmor;
     }
 
-    int Armor::getValue (const MWWorld::Ptr& ptr) const
+    int Armor::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         return ref->mBase->mData.mValue;
     }
@@ -222,10 +217,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Armor::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Armor::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref =
-            ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
@@ -289,9 +283,9 @@ namespace MWClass
         return record->mId;
     }
 
-    int Armor::getEffectiveArmorRating(const MWWorld::Ptr &ptr, const MWWorld::Ptr &actor) const
+    int Armor::getEffectiveArmorRating(const MWWorld::ConstPtr &ptr, const MWWorld::Ptr &actor) const
     {
-        MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
+        const MWWorld::LiveCellRef<ESM::Armor> *ref = ptr.get<ESM::Armor>();
 
         int armorSkillType = getEquipmentSkill(ptr);
         int armorSkill = actor.getClass().getSkill(actor, armorSkillType);
diff --git a/apps/openmw/mwclass/armor.hpp b/apps/openmw/mwclass/armor.hpp
index a7e63d6af..c989fcde0 100644
--- a/apps/openmw/mwclass/armor.hpp
+++ b/apps/openmw/mwclass/armor.hpp
@@ -22,7 +22,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -33,7 +33,7 @@ namespace MWClass
             virtual bool hasItemHealth (const MWWorld::Ptr& ptr) const;
             ///< \return Item health data available?
 
-            virtual int getItemMaxHealth (const MWWorld::Ptr& ptr) const;
+            virtual int getItemMaxHealth (const MWWorld::ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
@@ -43,17 +43,17 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getEquipmentSkill (const MWWorld::Ptr& ptr) const;
+            virtual int getEquipmentSkill (const MWWorld::ConstPtr& ptr) const;
             /// Return the index of the skill this item corresponds to when equiopped or -1, if there is
             /// no such skill.
 
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -88,7 +88,7 @@ namespace MWClass
             virtual bool canSell (const MWWorld::Ptr& item, int npcServices) const;
 
             /// Get the effective armor rating, factoring in the actor's skills, for the given armor.
-            virtual int getEffectiveArmorRating(const MWWorld::Ptr& ptr, const MWWorld::Ptr& actor) const;
+            virtual int getEffectiveArmorRating(const MWWorld::ConstPtr& armor, const MWWorld::Ptr& actor) const;
     };
 }
 
diff --git a/apps/openmw/mwclass/book.cpp b/apps/openmw/mwclass/book.cpp
index 1d645931d..49b53c480 100644
--- a/apps/openmw/mwclass/book.cpp
+++ b/apps/openmw/mwclass/book.cpp
@@ -53,10 +53,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Book::getName (const MWWorld::Ptr& ptr) const
+    std::string Book::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Book> *ref =
-            ptr.get<ESM::Book>();
+        const MWWorld::LiveCellRef<ESM::Book> *ref = ptr.get<ESM::Book>();
 
         return ref->mBase->mName;
     }
@@ -85,10 +84,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Book::getValue (const MWWorld::Ptr& ptr) const
+    int Book::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Book> *ref =
-            ptr.get<ESM::Book>();
+        const MWWorld::LiveCellRef<ESM::Book> *ref = ptr.get<ESM::Book>();
 
         return ref->mBase->mData.mValue;
     }
@@ -126,10 +124,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Book::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Book::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Book> *ref =
-            ptr.get<ESM::Book>();
+        const MWWorld::LiveCellRef<ESM::Book> *ref = ptr.get<ESM::Book>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/book.hpp b/apps/openmw/mwclass/book.hpp
index 90cb4d762..a4f230219 100644
--- a/apps/openmw/mwclass/book.hpp
+++ b/apps/openmw/mwclass/book.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -34,10 +34,10 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
diff --git a/apps/openmw/mwclass/clothing.cpp b/apps/openmw/mwclass/clothing.cpp
index 616f9676b..faa776e3a 100644
--- a/apps/openmw/mwclass/clothing.cpp
+++ b/apps/openmw/mwclass/clothing.cpp
@@ -52,10 +52,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Clothing::getName (const MWWorld::Ptr& ptr) const
+    std::string Clothing::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Clothing> *ref =
-            ptr.get<ESM::Clothing>();
+        const MWWorld::LiveCellRef<ESM::Clothing> *ref = ptr.get<ESM::Clothing>();
 
         return ref->mBase->mName;
     }
@@ -113,10 +112,9 @@ namespace MWClass
         return std::make_pair (slots_, false);
     }
 
-    int Clothing::getEquipmentSkill (const MWWorld::Ptr& ptr) const
+    int Clothing::getEquipmentSkill (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Clothing> *ref =
-            ptr.get<ESM::Clothing>();
+        const MWWorld::LiveCellRef<ESM::Clothing> *ref = ptr.get<ESM::Clothing>();
 
         if (ref->mBase->mData.mType==ESM::Clothing::Shoes)
             return ESM::Skill::Unarmored;
@@ -124,10 +122,9 @@ namespace MWClass
         return -1;
     }
 
-    int Clothing::getValue (const MWWorld::Ptr& ptr) const
+    int Clothing::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Clothing> *ref =
-            ptr.get<ESM::Clothing>();
+        const MWWorld::LiveCellRef<ESM::Clothing> *ref = ptr.get<ESM::Clothing>();
 
         return ref->mBase->mData.mValue;
     }
@@ -179,10 +176,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Clothing::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Clothing::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Clothing> *ref =
-            ptr.get<ESM::Clothing>();
+        const MWWorld::LiveCellRef<ESM::Clothing> *ref = ptr.get<ESM::Clothing>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/clothing.hpp b/apps/openmw/mwclass/clothing.hpp
index 0489f0b31..30d16f0d7 100644
--- a/apps/openmw/mwclass/clothing.hpp
+++ b/apps/openmw/mwclass/clothing.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -35,17 +35,17 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getEquipmentSkill (const MWWorld::Ptr& ptr) const;
+            virtual int getEquipmentSkill (const MWWorld::ConstPtr& ptr) const;
             /// Return the index of the skill this item corresponds to when equiopped or -1, if there is
             /// no such skill.
 
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
diff --git a/apps/openmw/mwclass/container.cpp b/apps/openmw/mwclass/container.cpp
index 79efc253e..9c39c9df1 100644
--- a/apps/openmw/mwclass/container.cpp
+++ b/apps/openmw/mwclass/container.cpp
@@ -193,10 +193,9 @@ namespace MWClass
         }
     }
 
-    std::string Container::getName (const MWWorld::Ptr& ptr) const
+    std::string Container::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Container> *ref =
-            ptr.get<ESM::Container>();
+        const MWWorld::LiveCellRef<ESM::Container> *ref = ptr.get<ESM::Container>();
 
         return ref->mBase->mName;
     }
@@ -231,10 +230,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Container::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Container::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Container> *ref =
-            ptr.get<ESM::Container>();
+        const MWWorld::LiveCellRef<ESM::Container> *ref = ptr.get<ESM::Container>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName;
diff --git a/apps/openmw/mwclass/container.hpp b/apps/openmw/mwclass/container.hpp
index 0c24ae03d..13593b1c0 100644
--- a/apps/openmw/mwclass/container.hpp
+++ b/apps/openmw/mwclass/container.hpp
@@ -23,7 +23,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -34,7 +34,7 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual MWWorld::ContainerStore& getContainerStore (const MWWorld::Ptr& ptr) const;
diff --git a/apps/openmw/mwclass/creature.cpp b/apps/openmw/mwclass/creature.cpp
index 9aa9871bb..fceae4060 100644
--- a/apps/openmw/mwclass/creature.cpp
+++ b/apps/openmw/mwclass/creature.cpp
@@ -188,10 +188,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Creature::getName (const MWWorld::Ptr& ptr) const
+    std::string Creature::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Creature> *ref =
-            ptr.get<ESM::Creature>();
+        const MWWorld::LiveCellRef<ESM::Creature> *ref = ptr.get<ESM::Creature>();
 
         return ref->mBase->mName;
     }
@@ -521,10 +520,9 @@ namespace MWClass
         return ptr.getRefData().getCustomData()->asCreatureCustomData().mMovement;
     }
 
-    MWGui::ToolTipInfo Creature::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Creature::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Creature> *ref =
-            ptr.get<ESM::Creature>();
+        const MWWorld::LiveCellRef<ESM::Creature> *ref = ptr.get<ESM::Creature>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName;
diff --git a/apps/openmw/mwclass/creature.hpp b/apps/openmw/mwclass/creature.hpp
index 70ffb3ba6..efb4715af 100644
--- a/apps/openmw/mwclass/creature.hpp
+++ b/apps/openmw/mwclass/creature.hpp
@@ -47,11 +47,11 @@ namespace MWClass
              virtual void insertObjectRendering (const MWWorld::Ptr& ptr, const std::string& model, MWRender::RenderingInterface& renderingInterface) const;
             ///< Add reference into a cell for rendering
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual MWMechanics::CreatureStats& getCreatureStats (const MWWorld::Ptr& ptr) const;
diff --git a/apps/openmw/mwclass/creaturelevlist.cpp b/apps/openmw/mwclass/creaturelevlist.cpp
index 2e4aef2fa..9bd5f9537 100644
--- a/apps/openmw/mwclass/creaturelevlist.cpp
+++ b/apps/openmw/mwclass/creaturelevlist.cpp
@@ -34,7 +34,7 @@ namespace MWClass
         return ptr.get<ESM::CreatureLevList>()->mBase->mId;
     }
 
-    std::string CreatureLevList::getName (const MWWorld::Ptr& ptr) const
+    std::string CreatureLevList::getName (const MWWorld::ConstPtr& ptr) const
     {
         return "";
     }
diff --git a/apps/openmw/mwclass/creaturelevlist.hpp b/apps/openmw/mwclass/creaturelevlist.hpp
index 7e1b7828a..4ada3cd86 100644
--- a/apps/openmw/mwclass/creaturelevlist.hpp
+++ b/apps/openmw/mwclass/creaturelevlist.hpp
@@ -14,7 +14,7 @@ namespace MWClass
             /// Return ID of \a ptr
             virtual std::string getId (const MWWorld::Ptr& ptr) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
diff --git a/apps/openmw/mwclass/door.cpp b/apps/openmw/mwclass/door.cpp
index 7c3176d52..47116cd7b 100644
--- a/apps/openmw/mwclass/door.cpp
+++ b/apps/openmw/mwclass/door.cpp
@@ -91,10 +91,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Door::getName (const MWWorld::Ptr& ptr) const
+    std::string Door::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Door> *ref =
-            ptr.get<ESM::Door>();
+        const MWWorld::LiveCellRef<ESM::Door> *ref = ptr.get<ESM::Door>();
 
         return ref->mBase->mName;
     }
@@ -239,10 +238,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Door::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Door::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Door> *ref =
-            ptr.get<ESM::Door>();
+        const MWWorld::LiveCellRef<ESM::Door> *ref = ptr.get<ESM::Door>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName;
diff --git a/apps/openmw/mwclass/door.hpp b/apps/openmw/mwclass/door.hpp
index c67c96e3e..384f38fa9 100644
--- a/apps/openmw/mwclass/door.hpp
+++ b/apps/openmw/mwclass/door.hpp
@@ -24,7 +24,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -35,7 +35,7 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             static std::string getDestination (const MWWorld::LiveCellRef<ESM::Door>& door);
diff --git a/apps/openmw/mwclass/ingredient.cpp b/apps/openmw/mwclass/ingredient.cpp
index b7d1cf3d9..95cf00d94 100644
--- a/apps/openmw/mwclass/ingredient.cpp
+++ b/apps/openmw/mwclass/ingredient.cpp
@@ -56,10 +56,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Ingredient::getName (const MWWorld::Ptr& ptr) const
+    std::string Ingredient::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Ingredient> *ref =
-            ptr.get<ESM::Ingredient>();
+        const MWWorld::LiveCellRef<ESM::Ingredient> *ref = ptr.get<ESM::Ingredient>();
 
         return ref->mBase->mName;
     }
@@ -77,10 +76,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Ingredient::getValue (const MWWorld::Ptr& ptr) const
+    int Ingredient::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Ingredient> *ref =
-            ptr.get<ESM::Ingredient>();
+        const MWWorld::LiveCellRef<ESM::Ingredient> *ref = ptr.get<ESM::Ingredient>();
 
         return ref->mBase->mData.mValue;
     }
@@ -128,10 +126,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Ingredient::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Ingredient::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Ingredient> *ref =
-            ptr.get<ESM::Ingredient>();
+        const MWWorld::LiveCellRef<ESM::Ingredient> *ref = ptr.get<ESM::Ingredient>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/ingredient.hpp b/apps/openmw/mwclass/ingredient.hpp
index 00862a220..a6740a399 100644
--- a/apps/openmw/mwclass/ingredient.hpp
+++ b/apps/openmw/mwclass/ingredient.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,13 +31,13 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
             ///< Return name of the script attached to ptr
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             virtual boost::shared_ptr<MWWorld::Action> use (const MWWorld::Ptr& ptr)
diff --git a/apps/openmw/mwclass/itemlevlist.cpp b/apps/openmw/mwclass/itemlevlist.cpp
index a70f31115..7690169c6 100644
--- a/apps/openmw/mwclass/itemlevlist.cpp
+++ b/apps/openmw/mwclass/itemlevlist.cpp
@@ -9,7 +9,7 @@ namespace MWClass
         return ptr.get<ESM::ItemLevList>()->mBase->mId;
     }
 
-    std::string ItemLevList::getName (const MWWorld::Ptr& ptr) const
+    std::string ItemLevList::getName (const MWWorld::ConstPtr& ptr) const
     {
         return "";
     }
diff --git a/apps/openmw/mwclass/itemlevlist.hpp b/apps/openmw/mwclass/itemlevlist.hpp
index 2b507135f..8a95b9adb 100644
--- a/apps/openmw/mwclass/itemlevlist.hpp
+++ b/apps/openmw/mwclass/itemlevlist.hpp
@@ -12,7 +12,7 @@ namespace MWClass
             /// Return ID of \a ptr
             virtual std::string getId (const MWWorld::Ptr& ptr) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
diff --git a/apps/openmw/mwclass/light.cpp b/apps/openmw/mwclass/light.cpp
index 615f9fac0..eb1c3bcc2 100644
--- a/apps/openmw/mwclass/light.cpp
+++ b/apps/openmw/mwclass/light.cpp
@@ -72,10 +72,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Light::getName (const MWWorld::Ptr& ptr) const
+    std::string Light::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Light> *ref =
-            ptr.get<ESM::Light>();
+        const MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
 
         if (ref->mBase->mModel.empty())
             return "";
@@ -116,10 +115,9 @@ namespace MWClass
         return std::make_pair (slots_, false);
     }
 
-    int Light::getValue (const MWWorld::Ptr& ptr) const
+    int Light::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Light> *ref =
-            ptr.get<ESM::Light>();
+        const MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
 
         return ref->mBase->mData.mValue;
     }
@@ -158,10 +156,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Light::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Light::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Light> *ref =
-            ptr.get<ESM::Light>();
+        const MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
@@ -201,9 +198,9 @@ namespace MWClass
         ptr.getCellRef().setChargeFloat(duration);
     }
 
-    float Light::getRemainingUsageTime (const MWWorld::Ptr& ptr) const
+    float Light::getRemainingUsageTime (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
+        const MWWorld::LiveCellRef<ESM::Light> *ref = ptr.get<ESM::Light>();
         if (ptr.getCellRef().getCharge() == -1)
             return static_cast<float>(ref->mBase->mData.mTime);
         else
diff --git a/apps/openmw/mwclass/light.hpp b/apps/openmw/mwclass/light.hpp
index b7ef199b0..5e04fdb0b 100644
--- a/apps/openmw/mwclass/light.hpp
+++ b/apps/openmw/mwclass/light.hpp
@@ -20,14 +20,14 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual boost::shared_ptr<MWWorld::Action> activate (const MWWorld::Ptr& ptr,
@@ -41,7 +41,7 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -62,7 +62,7 @@ namespace MWClass
             virtual void setRemainingUsageTime (const MWWorld::Ptr& ptr, float duration) const;
             ///< Sets the remaining duration of the object.
 
-            virtual float getRemainingUsageTime (const MWWorld::Ptr& ptr) const;
+            virtual float getRemainingUsageTime (const MWWorld::ConstPtr& ptr) const;
             ///< Returns the remaining duration of the object.
 
             virtual std::string getModel(const MWWorld::Ptr &ptr) const;
diff --git a/apps/openmw/mwclass/lockpick.cpp b/apps/openmw/mwclass/lockpick.cpp
index 3fae74be9..858a01992 100644
--- a/apps/openmw/mwclass/lockpick.cpp
+++ b/apps/openmw/mwclass/lockpick.cpp
@@ -51,10 +51,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Lockpick::getName (const MWWorld::Ptr& ptr) const
+    std::string Lockpick::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Lockpick> *ref =
-            ptr.get<ESM::Lockpick>();
+        const MWWorld::LiveCellRef<ESM::Lockpick> *ref = ptr.get<ESM::Lockpick>();
 
         return ref->mBase->mName;
     }
@@ -81,10 +80,9 @@ namespace MWClass
         return std::make_pair (slots_, false);
     }
 
-    int Lockpick::getValue (const MWWorld::Ptr& ptr) const
+    int Lockpick::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Lockpick> *ref =
-            ptr.get<ESM::Lockpick>();
+        const MWWorld::LiveCellRef<ESM::Lockpick> *ref = ptr.get<ESM::Lockpick>();
 
         return ref->mBase->mData.mValue;
     }
@@ -122,10 +120,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Lockpick::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Lockpick::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Lockpick> *ref =
-            ptr.get<ESM::Lockpick>();
+        const MWWorld::LiveCellRef<ESM::Lockpick> *ref = ptr.get<ESM::Lockpick>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
@@ -173,10 +170,9 @@ namespace MWClass
         return (npcServices & ESM::NPC::Picks) != 0;
     }
 
-    int Lockpick::getItemMaxHealth (const MWWorld::Ptr& ptr) const
+    int Lockpick::getItemMaxHealth (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Lockpick> *ref =
-            ptr.get<ESM::Lockpick>();
+        const MWWorld::LiveCellRef<ESM::Lockpick> *ref = ptr.get<ESM::Lockpick>();
 
         return ref->mBase->mData.mUses;
     }
diff --git a/apps/openmw/mwclass/lockpick.hpp b/apps/openmw/mwclass/lockpick.hpp
index 7e7ee78d5..44333eb45 100644
--- a/apps/openmw/mwclass/lockpick.hpp
+++ b/apps/openmw/mwclass/lockpick.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,7 +31,7 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
@@ -41,7 +41,7 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -65,7 +65,7 @@ namespace MWClass
 
             virtual float getWeight (const MWWorld::Ptr& ptr) const;
 
-            virtual int getItemMaxHealth (const MWWorld::Ptr& ptr) const;
+            virtual int getItemMaxHealth (const MWWorld::ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
 
             virtual bool hasItemHealth (const MWWorld::Ptr& ptr) const { return true; }
diff --git a/apps/openmw/mwclass/misc.cpp b/apps/openmw/mwclass/misc.cpp
index e5836bd96..57d5a1b1f 100644
--- a/apps/openmw/mwclass/misc.cpp
+++ b/apps/openmw/mwclass/misc.cpp
@@ -26,7 +26,7 @@
 
 namespace MWClass
 {
-    bool Miscellaneous::isGold (const MWWorld::Ptr& ptr) const
+    bool Miscellaneous::isGold (const MWWorld::ConstPtr& ptr) const
     {
         return Misc::StringUtils::ciEqual(ptr.getCellRef().getRefId(), "gold_001")
                         || Misc::StringUtils::ciEqual(ptr.getCellRef().getRefId(), "gold_005")
@@ -64,10 +64,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Miscellaneous::getName (const MWWorld::Ptr& ptr) const
+    std::string Miscellaneous::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
-            ptr.get<ESM::Miscellaneous>();
+        const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref = ptr.get<ESM::Miscellaneous>();
 
         return ref->mBase->mName;
     }
@@ -85,10 +84,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Miscellaneous::getValue (const MWWorld::Ptr& ptr) const
+    int Miscellaneous::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
-            ptr.get<ESM::Miscellaneous>();
+        const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref = ptr.get<ESM::Miscellaneous>();
 
         int value = ref->mBase->mData.mValue;
         if (ptr.getCellRef().getGoldValue() > 1 && ptr.getRefData().getCount() == 1)
@@ -140,10 +138,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Miscellaneous::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Miscellaneous::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
-            ptr.get<ESM::Miscellaneous>();
+        const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref = ptr.get<ESM::Miscellaneous>();
 
         MWGui::ToolTipInfo info;
 
@@ -249,10 +246,9 @@ namespace MWClass
         return ref->mBase->mData.mWeight;
     }
 
-    bool Miscellaneous::isKey(const MWWorld::Ptr &ptr) const
+    bool Miscellaneous::isKey(const MWWorld::ConstPtr &ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Miscellaneous> *ref =
-            ptr.get<ESM::Miscellaneous>();
+        const MWWorld::LiveCellRef<ESM::Miscellaneous> *ref = ptr.get<ESM::Miscellaneous>();
         return ref->mBase->mData.mIsKey != 0;
     }
 
diff --git a/apps/openmw/mwclass/misc.hpp b/apps/openmw/mwclass/misc.hpp
index e3215a6ad..a8ee52657 100644
--- a/apps/openmw/mwclass/misc.hpp
+++ b/apps/openmw/mwclass/misc.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,13 +31,13 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
             ///< Return name of the script attached to ptr
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -61,9 +61,9 @@ namespace MWClass
 
             virtual bool canSell (const MWWorld::Ptr& item, int npcServices) const;
 
-            virtual bool isKey (const MWWorld::Ptr &ptr) const;
+            virtual bool isKey (const MWWorld::ConstPtr &ptr) const;
 
-            virtual bool isGold (const MWWorld::Ptr& ptr) const;
+            virtual bool isGold (const MWWorld::ConstPtr& ptr) const;
     };
 }
 
diff --git a/apps/openmw/mwclass/npc.cpp b/apps/openmw/mwclass/npc.cpp
index bac555d1b..0d0978d37 100644
--- a/apps/openmw/mwclass/npc.cpp
+++ b/apps/openmw/mwclass/npc.cpp
@@ -252,6 +252,10 @@ namespace MWClass
         {
             return *this;
         }
+        virtual const NpcCustomData& asNpcCustomData() const
+        {
+            return *this;
+        }
     };
 
     MWWorld::CustomData *NpcCustomData::clone() const
@@ -436,9 +440,9 @@ namespace MWClass
 
     }
 
-    std::string Npc::getName (const MWWorld::Ptr& ptr) const
+    std::string Npc::getName (const MWWorld::ConstPtr& ptr) const
     {
-        if(getNpcStats(ptr).isWerewolf())
+        if(ptr.getRefData().getCustomData() && ptr.getRefData().getCustomData()->asNpcCustomData().mNpcStats.isWerewolf())
         {
             const MWBase::World *world = MWBase::Environment::get().getWorld();
             const MWWorld::Store<ESM::GameSetting> &store = world->getStore().get<ESM::GameSetting>();
@@ -446,7 +450,7 @@ namespace MWClass
             return store.find("sWerewolfPopup")->getString();
         }
 
-        MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
+        const MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
         return ref->mBase->mName;
     }
 
@@ -921,15 +925,15 @@ namespace MWClass
         registerClass (typeid (ESM::NPC).name(), instance);
     }
 
-    MWGui::ToolTipInfo Npc::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Npc::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
+        const MWWorld::LiveCellRef<ESM::NPC> *ref = ptr.get<ESM::NPC>();
 
         bool fullHelp = MWBase::Environment::get().getWindowManager()->getFullHelp();
         MWGui::ToolTipInfo info;
 
         info.caption = getName(ptr);
-        if(fullHelp && getNpcStats(ptr).isWerewolf())
+        if(fullHelp && ptr.getRefData().getCustomData() && ptr.getRefData().getCustomData()->asNpcCustomData().mNpcStats.isWerewolf())
         {
             info.caption += " (";
             info.caption += ref->mBase->mName;
diff --git a/apps/openmw/mwclass/npc.hpp b/apps/openmw/mwclass/npc.hpp
index 48277eb52..f5d9044a7 100644
--- a/apps/openmw/mwclass/npc.hpp
+++ b/apps/openmw/mwclass/npc.hpp
@@ -51,7 +51,7 @@ namespace MWClass
             virtual void insertObjectRendering (const MWWorld::Ptr& ptr, const std::string& model, MWRender::RenderingInterface& renderingInterface) const;
             ///< Add reference into a cell for rendering
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -64,7 +64,7 @@ namespace MWClass
             virtual MWWorld::ContainerStore& getContainerStore (const MWWorld::Ptr& ptr) const;
             ///< Return container store
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual MWWorld::InventoryStore& getInventoryStore (const MWWorld::Ptr& ptr) const;
diff --git a/apps/openmw/mwclass/potion.cpp b/apps/openmw/mwclass/potion.cpp
index 9816c3cbc..34f9922ea 100644
--- a/apps/openmw/mwclass/potion.cpp
+++ b/apps/openmw/mwclass/potion.cpp
@@ -54,10 +54,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Potion::getName (const MWWorld::Ptr& ptr) const
+    std::string Potion::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Potion> *ref =
-            ptr.get<ESM::Potion>();
+        const MWWorld::LiveCellRef<ESM::Potion> *ref = ptr.get<ESM::Potion>();
 
         return ref->mBase->mName;
     }
@@ -76,10 +75,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Potion::getValue (const MWWorld::Ptr& ptr) const
+    int Potion::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Potion> *ref =
-            ptr.get<ESM::Potion>();
+        const MWWorld::LiveCellRef<ESM::Potion> *ref = ptr.get<ESM::Potion>();
 
         return ref->mBase->mData.mValue;
     }
@@ -117,10 +115,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Potion::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Potion::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Potion> *ref =
-            ptr.get<ESM::Potion>();
+        const MWWorld::LiveCellRef<ESM::Potion> *ref = ptr.get<ESM::Potion>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/potion.hpp b/apps/openmw/mwclass/potion.hpp
index a38205257..10083a7cf 100644
--- a/apps/openmw/mwclass/potion.hpp
+++ b/apps/openmw/mwclass/potion.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,13 +31,13 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
             ///< Return name of the script attached to ptr
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             virtual boost::shared_ptr<MWWorld::Action> use (const MWWorld::Ptr& ptr) const;
diff --git a/apps/openmw/mwclass/probe.cpp b/apps/openmw/mwclass/probe.cpp
index 0e3de75d4..8882af507 100644
--- a/apps/openmw/mwclass/probe.cpp
+++ b/apps/openmw/mwclass/probe.cpp
@@ -51,10 +51,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Probe::getName (const MWWorld::Ptr& ptr) const
+    std::string Probe::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Probe> *ref =
-            ptr.get<ESM::Probe>();
+        const MWWorld::LiveCellRef<ESM::Probe> *ref = ptr.get<ESM::Probe>();
 
         return ref->mBase->mName;
     }
@@ -81,10 +80,9 @@ namespace MWClass
         return std::make_pair (slots_, false);
     }
 
-    int Probe::getValue (const MWWorld::Ptr& ptr) const
+    int Probe::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Probe> *ref =
-            ptr.get<ESM::Probe>();
+        const MWWorld::LiveCellRef<ESM::Probe> *ref = ptr.get<ESM::Probe>();
 
         return ref->mBase->mData.mValue;
     }
@@ -122,10 +120,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Probe::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Probe::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Probe> *ref =
-            ptr.get<ESM::Probe>();
+        const MWWorld::LiveCellRef<ESM::Probe> *ref = ptr.get<ESM::Probe>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
@@ -173,10 +170,9 @@ namespace MWClass
         return (npcServices & ESM::NPC::Probes) != 0;
     }
 
-    int Probe::getItemMaxHealth (const MWWorld::Ptr& ptr) const
+    int Probe::getItemMaxHealth (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Probe> *ref =
-            ptr.get<ESM::Probe>();
+        const MWWorld::LiveCellRef<ESM::Probe> *ref = ptr.get<ESM::Probe>();
 
         return ref->mBase->mData.mUses;
     }
diff --git a/apps/openmw/mwclass/probe.hpp b/apps/openmw/mwclass/probe.hpp
index a6da5ab9d..69cf614fd 100644
--- a/apps/openmw/mwclass/probe.hpp
+++ b/apps/openmw/mwclass/probe.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,7 +31,7 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
@@ -41,7 +41,7 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -65,7 +65,7 @@ namespace MWClass
 
             virtual float getWeight (const MWWorld::Ptr& ptr) const;
 
-            virtual int getItemMaxHealth (const MWWorld::Ptr& ptr) const;
+            virtual int getItemMaxHealth (const MWWorld::ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
 
             virtual bool hasItemHealth (const MWWorld::Ptr& ptr) const { return true; }
diff --git a/apps/openmw/mwclass/repair.cpp b/apps/openmw/mwclass/repair.cpp
index 700db167a..b52b06baf 100644
--- a/apps/openmw/mwclass/repair.cpp
+++ b/apps/openmw/mwclass/repair.cpp
@@ -50,10 +50,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Repair::getName (const MWWorld::Ptr& ptr) const
+    std::string Repair::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Repair> *ref =
-            ptr.get<ESM::Repair>();
+        const MWWorld::LiveCellRef<ESM::Repair> *ref = ptr.get<ESM::Repair>();
 
         return ref->mBase->mName;
     }
@@ -72,10 +71,9 @@ namespace MWClass
         return ref->mBase->mScript;
     }
 
-    int Repair::getValue (const MWWorld::Ptr& ptr) const
+    int Repair::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Repair> *ref =
-            ptr.get<ESM::Repair>();
+        const MWWorld::LiveCellRef<ESM::Repair> *ref = ptr.get<ESM::Repair>();
 
         return ref->mBase->mData.mValue;
     }
@@ -118,18 +116,16 @@ namespace MWClass
         return true;
     }
 
-    int Repair::getItemMaxHealth (const MWWorld::Ptr& ptr) const
+    int Repair::getItemMaxHealth (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Repair> *ref =
-            ptr.get<ESM::Repair>();
+        const MWWorld::LiveCellRef<ESM::Repair> *ref = ptr.get<ESM::Repair>();
 
         return ref->mBase->mData.mUses;
     }
 
-    MWGui::ToolTipInfo Repair::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Repair::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Repair> *ref =
-            ptr.get<ESM::Repair>();
+        const MWWorld::LiveCellRef<ESM::Repair> *ref = ptr.get<ESM::Repair>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/repair.hpp b/apps/openmw/mwclass/repair.hpp
index 3ec617bd3..ed17ff587 100644
--- a/apps/openmw/mwclass/repair.hpp
+++ b/apps/openmw/mwclass/repair.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,13 +31,13 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
             ///< Return name of the script attached to ptr
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
@@ -61,7 +61,7 @@ namespace MWClass
             virtual bool hasItemHealth (const MWWorld::Ptr& ptr) const;
             ///< \return Item health data available? (default implementation: false)
 
-            virtual int getItemMaxHealth (const MWWorld::Ptr& ptr) const;
+            virtual int getItemMaxHealth (const MWWorld::ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
             /// (default implementation: throw an exception)
 
diff --git a/apps/openmw/mwclass/static.cpp b/apps/openmw/mwclass/static.cpp
index 86019a5ad..f9d9f618a 100644
--- a/apps/openmw/mwclass/static.cpp
+++ b/apps/openmw/mwclass/static.cpp
@@ -42,7 +42,7 @@ namespace MWClass
         return "";
     }
 
-    std::string Static::getName (const MWWorld::Ptr& ptr) const
+    std::string Static::getName (const MWWorld::ConstPtr& ptr) const
     {
         return "";
     }
diff --git a/apps/openmw/mwclass/static.hpp b/apps/openmw/mwclass/static.hpp
index 3d78f949b..1748f86c6 100644
--- a/apps/openmw/mwclass/static.hpp
+++ b/apps/openmw/mwclass/static.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
diff --git a/apps/openmw/mwclass/weapon.cpp b/apps/openmw/mwclass/weapon.cpp
index cc5d8ed59..e363c942e 100644
--- a/apps/openmw/mwclass/weapon.cpp
+++ b/apps/openmw/mwclass/weapon.cpp
@@ -54,10 +54,9 @@ namespace MWClass
         return "";
     }
 
-    std::string Weapon::getName (const MWWorld::Ptr& ptr) const
+    std::string Weapon::getName (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         return ref->mBase->mName;
     }
@@ -76,10 +75,9 @@ namespace MWClass
         return (ref->mBase->mData.mType < 11); // thrown weapons and arrows/bolts don't have health, only quantity
     }
 
-    int Weapon::getItemMaxHealth (const MWWorld::Ptr& ptr) const
+    int Weapon::getItemMaxHealth (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         return ref->mBase->mData.mHealth;
     }
@@ -116,10 +114,9 @@ namespace MWClass
         return std::make_pair (slots_, stack);
     }
 
-    int Weapon::getEquipmentSkill (const MWWorld::Ptr& ptr) const
+    int Weapon::getEquipmentSkill (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         const int size = 12;
 
@@ -146,10 +143,9 @@ namespace MWClass
         return -1;
     }
 
-    int Weapon::getValue (const MWWorld::Ptr& ptr) const
+    int Weapon::getValue (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         return ref->mBase->mData.mValue;
     }
@@ -267,10 +263,9 @@ namespace MWClass
         return (ref->mBase->mName != "");
     }
 
-    MWGui::ToolTipInfo Weapon::getToolTipInfo (const MWWorld::Ptr& ptr) const
+    MWGui::ToolTipInfo Weapon::getToolTipInfo (const MWWorld::ConstPtr& ptr) const
     {
-        MWWorld::LiveCellRef<ESM::Weapon> *ref =
-            ptr.get<ESM::Weapon>();
+        const MWWorld::LiveCellRef<ESM::Weapon> *ref = ptr.get<ESM::Weapon>();
 
         MWGui::ToolTipInfo info;
         info.caption = ref->mBase->mName + MWGui::ToolTips::getCountString(ptr.getRefData().getCount());
diff --git a/apps/openmw/mwclass/weapon.hpp b/apps/openmw/mwclass/weapon.hpp
index 88282f5a3..916b61eae 100644
--- a/apps/openmw/mwclass/weapon.hpp
+++ b/apps/openmw/mwclass/weapon.hpp
@@ -20,7 +20,7 @@ namespace MWClass
 
             virtual void insertObject(const MWWorld::Ptr& ptr, const std::string& model, MWPhysics::PhysicsSystem& physics) const;
 
-            virtual std::string getName (const MWWorld::Ptr& ptr) const;
+            virtual std::string getName (const MWWorld::ConstPtr& ptr) const;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -31,13 +31,13 @@ namespace MWClass
             virtual bool hasToolTip (const MWWorld::Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const MWWorld::ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual bool hasItemHealth (const MWWorld::Ptr& ptr) const;
             ///< \return Item health data available?
 
-            virtual int getItemMaxHealth (const MWWorld::Ptr& ptr) const;
+            virtual int getItemMaxHealth (const MWWorld::ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
 
             virtual std::string getScript (const MWWorld::ConstPtr& ptr) const;
@@ -47,11 +47,11 @@ namespace MWClass
             ///< \return first: Return IDs of the slot this object can be equipped in; second: can object
             /// stay stacked when equipped?
 
-            virtual int getEquipmentSkill (const MWWorld::Ptr& ptr) const;
-            /// Return the index of the skill this item corresponds to when equiopped or -1, if there is
+            virtual int getEquipmentSkill (const MWWorld::ConstPtr& ptr) const;
+            /// Return the index of the skill this item corresponds to when equipped or -1, if there is
             /// no such skill.
 
-            virtual int getValue (const MWWorld::Ptr& ptr) const;
+            virtual int getValue (const MWWorld::ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
 
             static void registerSelf();
diff --git a/apps/openmw/mwworld/class.cpp b/apps/openmw/mwworld/class.cpp
index f8d4fbde4..85a5a5720 100644
--- a/apps/openmw/mwworld/class.cpp
+++ b/apps/openmw/mwworld/class.cpp
@@ -80,7 +80,7 @@ namespace MWWorld
         return false;
     }
 
-    int Class::getItemHealth(const Ptr &ptr) const
+    int Class::getItemHealth(const ConstPtr &ptr) const
     {
         if (ptr.getCellRef().getCharge() == -1)
             return getItemMaxHealth(ptr);
@@ -88,7 +88,7 @@ namespace MWWorld
             return ptr.getCellRef().getCharge();
     }
 
-    int Class::getItemMaxHealth (const Ptr& ptr) const
+    int Class::getItemMaxHealth (const ConstPtr& ptr) const
     {
         throw std::runtime_error ("class does not have item health");
     }
@@ -153,7 +153,7 @@ namespace MWWorld
         throw std::runtime_error ("class does not support time-based uses");
     }
 
-    float Class::getRemainingUsageTime (const Ptr& ptr) const
+    float Class::getRemainingUsageTime (const ConstPtr& ptr) const
     {
         return -1;
     }
@@ -193,12 +193,12 @@ namespace MWWorld
         return std::make_pair (std::vector<int>(), false);
     }
 
-    int Class::getEquipmentSkill (const Ptr& ptr) const
+    int Class::getEquipmentSkill (const ConstPtr& ptr) const
     {
         return -1;
     }
 
-    int Class::getValue (const Ptr& ptr) const
+    int Class::getValue (const ConstPtr& ptr) const
     {
         throw std::logic_error ("value not supported by this class");
     }
@@ -272,7 +272,7 @@ namespace MWWorld
         throw std::runtime_error ("class does not have any inventory icon");
     }
 
-    MWGui::ToolTipInfo Class::getToolTipInfo (const Ptr& ptr) const
+    MWGui::ToolTipInfo Class::getToolTipInfo (const ConstPtr& ptr) const
     {
         throw std::runtime_error ("class does not have a tool tip");
     }
@@ -447,7 +447,7 @@ namespace MWWorld
         return -1;
     }
 
-    int Class::getEffectiveArmorRating(const Ptr &ptr, const Ptr &actor) const
+    int Class::getEffectiveArmorRating(const ConstPtr &armor, const Ptr &actor) const
     {
         throw std::runtime_error("class does not support armor ratings");
     }
diff --git a/apps/openmw/mwworld/class.hpp b/apps/openmw/mwworld/class.hpp
index 38ca7fcc1..341094964 100644
--- a/apps/openmw/mwworld/class.hpp
+++ b/apps/openmw/mwworld/class.hpp
@@ -86,7 +86,7 @@ namespace MWWorld
             virtual void insertObject(const Ptr& ptr, const std::string& mesh, MWPhysics::PhysicsSystem& physics) const;
             ///< Add reference into a cell for rendering (default implementation: don't render anything).
 
-            virtual std::string getName (const Ptr& ptr) const = 0;
+            virtual std::string getName (const ConstPtr& ptr) const = 0;
             ///< \return name (the one that is to be presented to the user; not the internal one);
             /// can return an empty string.
 
@@ -101,7 +101,7 @@ namespace MWWorld
             virtual bool hasToolTip (const Ptr& ptr) const;
             ///< @return true if this object has a tooltip when focused (default implementation: false)
 
-            virtual MWGui::ToolTipInfo getToolTipInfo (const Ptr& ptr) const;
+            virtual MWGui::ToolTipInfo getToolTipInfo (const ConstPtr& ptr) const;
             ///< @return the content of the tool tip to be displayed. raises exception if the object has no tooltip.
 
             virtual MWMechanics::NpcStats& getNpcStats (const Ptr& ptr) const;
@@ -111,10 +111,10 @@ namespace MWWorld
             virtual bool hasItemHealth (const Ptr& ptr) const;
             ///< \return Item health data available? (default implementation: false)
 
-            virtual int getItemHealth (const Ptr& ptr) const;
+            virtual int getItemHealth (const ConstPtr& ptr) const;
             ///< Return current item health or throw an exception if class does not have item health
 
-            virtual int getItemMaxHealth (const Ptr& ptr) const;
+            virtual int getItemMaxHealth (const ConstPtr& ptr) const;
             ///< Return item max health or throw an exception, if class does not have item health
             /// (default implementation: throw an exception)
 
@@ -167,7 +167,7 @@ namespace MWWorld
             ///< Sets the remaining duration of the object, such as an equippable light
             /// source. (default implementation: throw an exception)
 
-            virtual float getRemainingUsageTime (const Ptr& ptr) const;
+            virtual float getRemainingUsageTime (const ConstPtr& ptr) const;
             ///< Returns the remaining duration of the object, such as an equippable light
             /// source. (default implementation: -1, i.e. infinite)
 
@@ -193,13 +193,13 @@ namespace MWWorld
             ///
             /// Default implementation: return (empty vector, false).
 
-            virtual int getEquipmentSkill (const Ptr& ptr)
+            virtual int getEquipmentSkill (const ConstPtr& ptr)
                 const;
             /// Return the index of the skill this item corresponds to when equiopped or -1, if there is
             /// no such skill.
             /// (default implementation: return -1)
 
-            virtual int getValue (const Ptr& ptr) const;
+            virtual int getValue (const ConstPtr& ptr) const;
             ///< Return trade value of the object. Throws an exception, if the object can't be traded.
             /// (default implementation: throws an exception)
 
@@ -279,9 +279,9 @@ namespace MWWorld
 
             virtual bool isPersistent (const MWWorld::Ptr& ptr) const;
 
-            virtual bool isKey (const MWWorld::Ptr& ptr) const { return false; }
+            virtual bool isKey (const MWWorld::ConstPtr& ptr) const { return false; }
 
-            virtual bool isGold(const MWWorld::Ptr& ptr) const { return false; };
+            virtual bool isGold(const MWWorld::ConstPtr& ptr) const { return false; };
             
             /// Get a blood texture suitable for \a ptr (see Blood Texture 0-2 in Morrowind.ini)
             virtual int getBloodTexture (const MWWorld::Ptr& ptr) const;
@@ -344,7 +344,7 @@ namespace MWWorld
             virtual int getPrimaryFactionRank (const MWWorld::Ptr& ptr) const;
 
             /// Get the effective armor rating, factoring in the actor's skills, for the given armor.
-            virtual int getEffectiveArmorRating(const MWWorld::Ptr& ptr, const MWWorld::Ptr& actor) const;
+            virtual int getEffectiveArmorRating(const MWWorld::ConstPtr& armor, const MWWorld::Ptr& actor) const;
     };
 }
 
diff --git a/apps/openmw/mwworld/customdata.cpp b/apps/openmw/mwworld/customdata.cpp
index 8edbb345f..dce1e9fdd 100644
--- a/apps/openmw/mwworld/customdata.cpp
+++ b/apps/openmw/mwworld/customdata.cpp
@@ -21,6 +21,13 @@ MWClass::NpcCustomData &CustomData::asNpcCustomData()
     throw std::logic_error(error.str());
 }
 
+const MWClass::NpcCustomData &CustomData::asNpcCustomData() const
+{
+    std::stringstream error;
+    error << "bad cast " << typeid(this).name() << " to NpcCustomData";
+    throw std::logic_error(error.str());
+}
+
 MWClass::ContainerCustomData &CustomData::asContainerCustomData()
 {
     std::stringstream error;
diff --git a/apps/openmw/mwworld/customdata.hpp b/apps/openmw/mwworld/customdata.hpp
index 8c3890580..407962ee0 100644
--- a/apps/openmw/mwworld/customdata.hpp
+++ b/apps/openmw/mwworld/customdata.hpp
@@ -26,6 +26,7 @@ namespace MWWorld
             virtual MWClass::CreatureCustomData& asCreatureCustomData();
 
             virtual MWClass::NpcCustomData& asNpcCustomData();
+            virtual const MWClass::NpcCustomData& asNpcCustomData() const;
 
             virtual MWClass::ContainerCustomData& asContainerCustomData();