diff --git a/apps/openmw/mwgui/quickkeysmenu.cpp b/apps/openmw/mwgui/quickkeysmenu.cpp
index 02512425d..6d51420f0 100644
--- a/apps/openmw/mwgui/quickkeysmenu.cpp
+++ b/apps/openmw/mwgui/quickkeysmenu.cpp
@@ -440,7 +440,7 @@ namespace MWGui
 
         for (MWMechanics::Spells::TIterator it = spells.begin(); it != spells.end(); ++it)
         {
-            spellList.push_back(*it);
+            spellList.push_back (it->first);
         }
 
         const MWWorld::ESMStore &esmStore =
diff --git a/apps/openmw/mwgui/spellbuyingwindow.cpp b/apps/openmw/mwgui/spellbuyingwindow.cpp
index a41f401a5..11f090494 100644
--- a/apps/openmw/mwgui/spellbuyingwindow.cpp
+++ b/apps/openmw/mwgui/spellbuyingwindow.cpp
@@ -98,19 +98,19 @@ namespace MWGui
 
         MWMechanics::Spells& playerSpells = MWWorld::Class::get (player).getCreatureStats (player).getSpells();
         MWMechanics::Spells& merchantSpells = MWWorld::Class::get (actor).getCreatureStats (actor).getSpells();
-         
+
         for (MWMechanics::Spells::TIterator iter = merchantSpells.begin(); iter!=merchantSpells.end(); ++iter)
         {
             const ESM::Spell* spell =
-                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (*iter);
-            
+                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (iter->first);
+
             if (spell->mData.mType!=ESM::Spell::ST_Spell)
                 continue; // don't try to sell diseases, curses or powers
-            
+
             if (std::find (playerSpells.begin(), playerSpells.end(), *iter)!=playerSpells.end())
                 continue; // we have that spell already
-            
-            addSpell (*iter);
+
+            addSpell (iter->first);
         }
 
         updateLabels();
diff --git a/apps/openmw/mwgui/spellcreationdialog.cpp b/apps/openmw/mwgui/spellcreationdialog.cpp
index 69d69519f..839586452 100644
--- a/apps/openmw/mwgui/spellcreationdialog.cpp
+++ b/apps/openmw/mwgui/spellcreationdialog.cpp
@@ -436,7 +436,7 @@ namespace MWGui
         for (MWMechanics::Spells::TIterator it = spells.begin(); it != spells.end(); ++it)
         {
             const ESM::Spell* spell =
-                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find(*it);
+                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (it->first);
 
             // only normal spells count
             if (spell->mData.mType != ESM::Spell::ST_Spell)
diff --git a/apps/openmw/mwgui/spellwindow.cpp b/apps/openmw/mwgui/spellwindow.cpp
index d62b23de4..47e1d739a 100644
--- a/apps/openmw/mwgui/spellwindow.cpp
+++ b/apps/openmw/mwgui/spellwindow.cpp
@@ -139,7 +139,7 @@ namespace MWGui
 
         for (MWMechanics::Spells::TIterator it = spells.begin(); it != spells.end(); ++it)
         {
-            spellList.push_back(*it);
+            spellList.push_back (it->first);
         }
 
         const MWWorld::ESMStore &esmStore =
diff --git a/apps/openmw/mwmechanics/spells.cpp b/apps/openmw/mwmechanics/spells.cpp
index ef084f479..32acca2f0 100644
--- a/apps/openmw/mwmechanics/spells.cpp
+++ b/apps/openmw/mwmechanics/spells.cpp
@@ -29,13 +29,13 @@ namespace MWMechanics
 
     void Spells::add (const std::string& spellId)
     {
-        if (std::find (mSpells.begin(), mSpells.end(), spellId)==mSpells.end())
-            mSpells.push_back (spellId);
+        if (mSpells.find (spellId)==mSpells.end())
+            mSpells.insert (std::make_pair (spellId, -1));
     }
 
     void Spells::remove (const std::string& spellId)
     {
-        TContainer::iterator iter = std::find (mSpells.begin(), mSpells.end(), spellId);
+        TContainer::iterator iter = mSpells.find (spellId);
 
         if (iter!=mSpells.end())
             mSpells.erase (iter);
@@ -51,7 +51,7 @@ namespace MWMechanics
         for (TIterator iter = mSpells.begin(); iter!=mSpells.end(); ++iter)
         {
             const ESM::Spell *spell =
-                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (*iter);
+                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (iter->first);
 
             if (spell->mData.mType==ESM::Spell::ST_Ability || spell->mData.mType==ESM::Spell::ST_Blight ||
                 spell->mData.mType==ESM::Spell::ST_Disease || spell->mData.mType==ESM::Spell::ST_Curse)
@@ -75,18 +75,18 @@ namespace MWMechanics
     {
         return mSelectedSpell;
     }
-    
+
     bool Spells::hasCommonDisease() const
     {
         for (TIterator iter = mSpells.begin(); iter!=mSpells.end(); ++iter)
         {
             const ESM::Spell *spell =
-                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (*iter);
-        
+                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (iter->first);
+
             if (spell->mData.mFlags & ESM::Spell::ST_Disease)
                 return true;
         }
-        
+
         return false;
     }
 
@@ -95,12 +95,12 @@ namespace MWMechanics
         for (TIterator iter = mSpells.begin(); iter!=mSpells.end(); ++iter)
         {
             const ESM::Spell *spell =
-                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (*iter);
-        
+                MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find (iter->first);
+
             if (spell->mData.mFlags & ESM::Spell::ST_Blight)
                 return true;
         }
-        
-        return false;    
+
+        return false;
     }
 }
diff --git a/apps/openmw/mwmechanics/spells.hpp b/apps/openmw/mwmechanics/spells.hpp
index 12308661b..b4d058896 100644
--- a/apps/openmw/mwmechanics/spells.hpp
+++ b/apps/openmw/mwmechanics/spells.hpp
@@ -1,7 +1,7 @@
 #ifndef GAME_MWMECHANICS_SPELLS_H
 #define GAME_MWMECHANICS_SPELLS_H
 
-#include <vector>
+#include <map>
 #include <string>
 
 namespace ESM
@@ -21,12 +21,12 @@ namespace MWMechanics
     {
         public:
 
-            typedef std::vector<std::string> TContainer;
+            typedef std::map<std::string, float> TContainer; // ID, magnitude
             typedef TContainer::const_iterator TIterator;
 
         private:
 
-            std::vector<std::string> mSpells;
+            TContainer mSpells;
             std::string mSelectedSpell;
 
             void addSpell (const ESM::Spell *, MagicEffects& effects) const;
@@ -55,10 +55,10 @@ namespace MWMechanics
 
             const std::string getSelectedSpell() const;
             ///< May return an empty string.
-            
+
             bool hasCommonDisease() const;
 
-            bool hasBlightDisease() const;            
+            bool hasBlightDisease() const;
     };
 }
 
diff --git a/apps/openmw/mwscript/statsextensions.cpp b/apps/openmw/mwscript/statsextensions.cpp
index 31ea7518b..530d44c9d 100644
--- a/apps/openmw/mwscript/statsextensions.cpp
+++ b/apps/openmw/mwscript/statsextensions.cpp
@@ -485,7 +485,7 @@ namespace MWScript
                     for (MWMechanics::Spells::TIterator iter (
                         MWWorld::Class::get (ptr).getCreatureStats (ptr).getSpells().begin());
                         iter!=MWWorld::Class::get (ptr).getCreatureStats (ptr).getSpells().end(); ++iter)
-                        if (*iter==id)
+                        if (iter->first==id)
                         {
                             value = 1;
                             break;
@@ -1188,7 +1188,7 @@ namespace MWScript
             extensions.registerFunction ("getpccrimelevel", 'f', "", opcodeGetPCCrimeLevel);
             extensions.registerInstruction ("setpccrimelevel", "f", opcodeSetPCCrimeLevel);
             extensions.registerInstruction ("modpccrimelevel", "f", opcodeModPCCrimeLevel);
- 
+
             extensions.registerInstruction ("addspell", "c", opcodeAddSpell, opcodeAddSpellExplicit);
             extensions.registerInstruction ("removespell", "c", opcodeRemoveSpell,
                 opcodeRemoveSpellExplicit);
@@ -1286,7 +1286,7 @@ namespace MWScript
             interpreter.installSegment5 (opcodeGetPCCrimeLevel, new OpGetPCCrimeLevel);
             interpreter.installSegment5 (opcodeSetPCCrimeLevel, new OpSetPCCrimeLevel);
             interpreter.installSegment5 (opcodeModPCCrimeLevel, new OpModPCCrimeLevel);
- 
+
             interpreter.installSegment5 (opcodeAddSpell, new OpAddSpell<ImplicitRef>);
             interpreter.installSegment5 (opcodeAddSpellExplicit, new OpAddSpell<ExplicitRef>);
             interpreter.installSegment5 (opcodeRemoveSpell, new OpRemoveSpell<ImplicitRef>);