diff --git a/apps/openmw/mwmechanics/npcstats.cpp b/apps/openmw/mwmechanics/npcstats.cpp
index cdb9770290..6c95c53721 100644
--- a/apps/openmw/mwmechanics/npcstats.cpp
+++ b/apps/openmw/mwmechanics/npcstats.cpp
@@ -3,6 +3,15 @@
 
 #include <stdexcept>
 
+#include <components/esm/loadskil.hpp>
+#include <components/esm/loadclas.hpp>
+#include <components/esm/loadgmst.hpp>
+
+#include <components/esm_store/store.hpp>
+
+#include "../mwbase/environment.hpp"
+#include "../mwbase/world.hpp"
+
 MWMechanics::NpcStats::NpcStats()
 : mMovementFlags (0), mDrawState (DrawState_Nothing)
 {}
@@ -55,3 +64,62 @@ const std::map<std::string, int>& MWMechanics::NpcStats::getFactionRanks() const
 {
     return mFactionRank;
 }
+
+float MWMechanics::NpcStats::getSkillGain (int skillIndex, const ESM::Class& class_, int usageType,
+    int level) const
+{
+    if (level<0)
+        level = static_cast<int> (getSkill (skillIndex).getBase());
+
+    const ESM::Skill *skill = MWBase::Environment::get().getWorld()->getStore().skills.find (skillIndex);
+
+    float skillFactor = 1;
+
+    if (usageType>=4)
+        throw std::runtime_error ("skill usage type out of range");
+
+    if (usageType>0)
+    {
+        skillFactor = skill->data.useValue[usageType];
+
+        if (skillFactor<=0)
+            throw std::runtime_error ("invalid skill gain factor");
+    }
+
+    float typeFactor =
+        MWBase::Environment::get().getWorld()->getStore().gameSettings.find ("fMiscSkillBonus")->f;
+
+    for (int i=0; i<5; ++i)
+        if (class_.data.skills[i][0]==skillIndex)
+        {
+            typeFactor =
+                MWBase::Environment::get().getWorld()->getStore().gameSettings.find ("fMinorSkillBonus")->f;
+
+            break;
+        }
+
+    for (int i=0; i<5; ++i)
+        if (class_.data.skills[i][1]==skillIndex)
+        {
+            typeFactor =
+                MWBase::Environment::get().getWorld()->getStore().gameSettings.find ("fMajorSkillBonus")->f;
+
+            break;
+        }
+
+    if (typeFactor<=0)
+        throw std::runtime_error ("invalid skill type factor");
+
+    float specialisationFactor = 1;
+
+    if (skill->data.specialization==class_.data.specialization)
+    {
+        specialisationFactor =
+            MWBase::Environment::get().getWorld()->getStore().gameSettings.find ("fSpecialSkillBonus")->f;
+
+        if (specialisationFactor<=0)
+            throw std::runtime_error ("invalid skill specialisation factor");
+    }
+
+    return 1.0 / (level +1) * (1.0 / skillFactor) * typeFactor * specialisationFactor;
+}
diff --git a/apps/openmw/mwmechanics/npcstats.hpp b/apps/openmw/mwmechanics/npcstats.hpp
index 16a777b71a..0264042723 100644
--- a/apps/openmw/mwmechanics/npcstats.hpp
+++ b/apps/openmw/mwmechanics/npcstats.hpp
@@ -8,6 +8,11 @@
 #include "stat.hpp"
 #include "drawstate.hpp"
 
+namespace ESM
+{
+    struct Class;
+}
+
 namespace MWMechanics
 {
     /// \brief Additional stats for NPCs
@@ -59,6 +64,12 @@ namespace MWMechanics
             std::map<std::string, int>& getFactionRanks();
 
             const std::map<std::string, int>& getFactionRanks() const;
+
+            float getSkillGain (int skillIndex, const ESM::Class& class_, int usageType = -1,
+                int level = -1) const;
+            ///< \param usageType: Usage specific factor, specified in the respective skill record;
+            /// -1: use a factor of 1.0 instead.
+            /// \param level Level to base calculation on; -1: use current level.
     };
 }