diff --git a/CInterface/Battling/Creature.cpp b/CInterface/Battling/Creature.cpp
index b24fb05..9e4f014 100644
--- a/CInterface/Battling/Creature.cpp
+++ b/CInterface/Battling/Creature.cpp
@@ -4,7 +4,7 @@ using namespace CreatureLib::Battling;
 
 export uint8_t CreatureLib_Creature_Construct(Creature*& out, const BattleLibrary* library,
                                               const CreatureLib::Library::CreatureSpecies* species,
-                                              const CreatureLib::Library::SpeciesVariant* variant, uint8_t level,
+                                              const CreatureLib::Library::SpeciesVariant* variant, level_int_t level,
                                               uint32_t experience, uint32_t uid, CreatureLib::Library::Gender gender,
                                               uint8_t coloring, const CreatureLib::Library::Item* heldItem,
                                               const char* nickname, bool secretTalent, uint8_t talent,
@@ -32,7 +32,7 @@ export uint8_t CreatureLib_Creature_ChangeVariant(Creature* p, const CreatureLib
     Try(p->ChangeVariant(variant);)
 }
 
-SIMPLE_GET_FUNC(Creature, GetLevel, uint8_t);
+SIMPLE_GET_FUNC(Creature, GetLevel, level_int_t);
 SIMPLE_GET_FUNC(Creature, GetExperience, uint32_t);
 SIMPLE_GET_FUNC(Creature, GetUniqueIdentifier, uint32_t);
 SIMPLE_GET_FUNC(Creature, GetGender, CreatureLib::Library::Gender);
diff --git a/CInterface/Library/GrowthRate.cpp b/CInterface/Library/GrowthRate.cpp
index 24af7d3..e3f52bb 100644
--- a/CInterface/Library/GrowthRate.cpp
+++ b/CInterface/Library/GrowthRate.cpp
@@ -9,8 +9,8 @@ export GrowthRate* CreatureLib_LookupGrowthRate_Construct(uint32_t experiencePer
     return new LookupGrowthRate(exp);
 };
 
-export uint8_t CreatureLib_ExternGrowthRate_Construct(GrowthRate*& out, uint8_t (*calcLevel)(uint32_t),
-                                                      uint32_t (*calcExperience)(uint8_t)) {
+export uint8_t CreatureLib_ExternGrowthRate_Construct(GrowthRate*& out, level_int_t (*calcLevel)(uint32_t),
+                                                      uint32_t (*calcExperience)(level_int_t)) {
     Try(out = new ExternGrowthRate(calcLevel, calcExperience);)
 };
 
@@ -18,10 +18,10 @@ export void CreatureLib_GrowthRate_Destruct(const GrowthRate* p) { delete p; }
 export void CreatureLib_LookupGrowthRate_Destruct(const LookupGrowthRate* p) { delete p; }
 export void CreatureLib_ExternGrowthRate_Destruct(const ExternGrowthRate* p) { delete p; }
 
-export uint8_t CreatureLib_GrowthRate_CalculateLevel(uint8_t& out, const GrowthRate* p, uint32_t experience) {
+export uint8_t CreatureLib_GrowthRate_CalculateLevel(level_int_t& out, const GrowthRate* p, uint32_t experience) {
     Try(out = p->CalculateLevel(experience);)
 }
 
-export uint8_t CreatureLib_GrowthRate_CalculateExperience(uint32_t& out, const GrowthRate* p, uint8_t level) {
+export uint8_t CreatureLib_GrowthRate_CalculateExperience(uint32_t& out, const GrowthRate* p, level_int_t level) {
     Try(out = p->CalculateExperience(level);)
 }
\ No newline at end of file
diff --git a/CInterface/Library/GrowthRateLibrary.cpp b/CInterface/Library/GrowthRateLibrary.cpp
index e6eab00..d377f53 100644
--- a/CInterface/Library/GrowthRateLibrary.cpp
+++ b/CInterface/Library/GrowthRateLibrary.cpp
@@ -8,22 +8,22 @@ export GrowthRateLibrary* CreatureLib_GrowthRateLibrary_Construct(size_t initial
 
 export void CreatureLib_GrowthRateLibrary_Destruct(GrowthRateLibrary* p) { delete p; }
 
-export uint8_t CreatureLib_GrowthRateLibrary_CalculateLevel(uint8_t& out, GrowthRateLibrary* library,
+export uint8_t CreatureLib_GrowthRateLibrary_CalculateLevel(level_int_t& out, GrowthRateLibrary* library,
                                                             const char* growthRate, uint32_t experience) {
     Try(out = library->CalculateLevel(ArbUt::StringView::CalculateHash(growthRate), experience);)
 }
-export uint8_t CreatureLib_GrowthRateLibrary_CalculateLevelWithHash(uint8_t& out, GrowthRateLibrary* library,
+export uint8_t CreatureLib_GrowthRateLibrary_CalculateLevelWithHash(level_int_t& out, GrowthRateLibrary* library,
                                                                     uint32_t growthRateHash, uint32_t experience) {
     Try(out = library->CalculateLevel(growthRateHash, experience);)
 }
 
 export uint8_t CreatureLib_GrowthRateLibrary_CalculateExperience(uint32_t& out, GrowthRateLibrary* library,
-                                                                 const char* growthRate, uint8_t level) {
+                                                                 const char* growthRate, level_int_t level) {
     Try(out = library->CalculateExperience(ArbUt::StringView::CalculateHash(growthRate), level);)
 }
 
 export uint8_t CreatureLib_GrowthRateLibrary_CalculateExperienceWithHash(uint32_t& out, GrowthRateLibrary* library,
-                                                                         uint32_t growthRateHash, uint8_t level) {
+                                                                         uint32_t growthRateHash, level_int_t level) {
     Try(out = library->CalculateExperience(growthRateHash, level);)
 }
 export uint8_t CreatureLib_GrowthRateLibrary_AddGrowthRate(GrowthRateLibrary* library, const char* growthRateName,
diff --git a/CInterface/Library/LearnableAttacks.cpp b/CInterface/Library/LearnableAttacks.cpp
index 2644990..fe35ef9 100644
--- a/CInterface/Library/LearnableAttacks.cpp
+++ b/CInterface/Library/LearnableAttacks.cpp
@@ -8,7 +8,7 @@ export uint8_t CreatureLib_LearnableAttacks_Construct(LearnableAttacks*& out, si
 
 export void CreatureLib_LearnableAttacks_Destruct(LearnableAttacks* p) { delete p; }
 
-export void CreatureLib_LearnableAttacks_AddLevelAttack(LearnableAttacks* p, uint8_t level, const AttackData* attack) {
+export void CreatureLib_LearnableAttacks_AddLevelAttack(LearnableAttacks* p, level_int_t level, const AttackData* attack) {
     p->AddLevelAttack(level, attack);
 }
 
diff --git a/CInterface/Library/LibrarySettings.cpp b/CInterface/Library/LibrarySettings.cpp
index 66aab1f..5badba6 100644
--- a/CInterface/Library/LibrarySettings.cpp
+++ b/CInterface/Library/LibrarySettings.cpp
@@ -8,5 +8,5 @@ export const LibrarySettings* CreatureLib_LibrarySettings_Construct(uint8_t maxi
 
 export void CreatureLib_LibrarySettings_Destruct(const LibrarySettings* p) { delete p; }
 
-SIMPLE_GET_FUNC(LibrarySettings, GetMaximalLevel, uint8_t);
+SIMPLE_GET_FUNC(LibrarySettings, GetMaximalLevel, level_int_t);
 SIMPLE_GET_FUNC(LibrarySettings, GetMaximalAttacks, uint8_t);
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5e67344..e6aa047 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,7 @@ option(WINDOWS "Whether the build target is Windows or not." OFF)
 option(SHARED "Whether we should build a shared library, instead of a static one." OFF)
 option(TESTS "Whether the test executable should be build as well." OFF)
 option(STATICC "Whether gcc and stdc++ should be linked statically to the library." OFF)
+set(LEVEL_SIZE "8" CACHE STRING "Number of bits to store the level as. Can be 8, 16, 32, or 64")
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     add_compile_options(-fconcepts)
@@ -32,6 +33,18 @@ if (SHARED)
     set(LIBTYPE SHARED)
 endif (SHARED)
 
+if (LEVEL_SIZE STREQUAL "8")
+    add_definitions(-DLEVEL_U8)
+elseif (LEVEL_SIZE STREQUAL "16")
+    add_definitions(-DLEVEL_U16)
+elseif (LEVEL_SIZE STREQUAL "32")
+    add_definitions(-DLEVEL_U32)
+elseif (LEVEL_SIZE STREQUAL "64")
+    add_definitions(-DLEVEL_U64)
+else ()
+    message(FATAL_ERROR, "Invalid level size was given.")
+endif ()
+
 file(GLOB_RECURSE LIBRARY_SRC_FILES
         "src/*.cpp" "src/*.hpp" "CInterface/*.cpp" "CInterface/*.hpp")
 add_library(CreatureLib SHARED ${LIBRARY_SRC_FILES})
diff --git a/src/Battling/Models/Creature.cpp b/src/Battling/Models/Creature.cpp
index 75618bb..9d901cd 100644
--- a/src/Battling/Models/Creature.cpp
+++ b/src/Battling/Models/Creature.cpp
@@ -10,7 +10,7 @@ using namespace CreatureLib;
 namespace CreatureLib::Battling {
     Creature::Creature(ArbUt::BorrowedPtr<const BattleLibrary> library,
                        const ArbUt::BorrowedPtr<const Library::CreatureSpecies>& species,
-                       const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant, uint8_t level,
+                       const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant, level_int_t level,
                        uint32_t experience, uint32_t uid, Library::Gender gender, uint8_t coloring,
                        const ArbUt::BorrowedPtr<const Library::Item> heldItem, const std::string& nickname,
                        const Library::TalentIndex& talent, const std::vector<LearnedAttack*>& attacks,
diff --git a/src/Battling/Models/Creature.hpp b/src/Battling/Models/Creature.hpp
index bac7e91..9761d3d 100644
--- a/src/Battling/Models/Creature.hpp
+++ b/src/Battling/Models/Creature.hpp
@@ -4,6 +4,7 @@
 #include <Arbutils/Collections/List.hpp>
 #include <Arbutils/Memory/BorrowedPtr.hpp>
 #include <Arbutils/Memory/UniquePtrList.hpp>
+#include "../../Defines.hpp"
 #include "../../Library/ClampedStatisticSet.hpp"
 #include "../../Library/CreatureData/CreatureSpecies.hpp"
 #include "../../Library/Items/Item.hpp"
@@ -29,7 +30,7 @@ namespace CreatureLib::Battling {
         ArbUt::BorrowedPtr<const Library::CreatureSpecies> _displaySpecies = nullptr;
         ArbUt::BorrowedPtr<const Library::SpeciesVariant> _displayVariant = nullptr;
 
-        uint8_t _level;
+        level_int_t _level;
         uint32_t _experience;
         uint32_t _uniqueIdentifier;
         Library::Gender _gender;
@@ -67,8 +68,8 @@ namespace CreatureLib::Battling {
     public:
         Creature(ArbUt::BorrowedPtr<const BattleLibrary> library,
                  const ArbUt::BorrowedPtr<const Library::CreatureSpecies>& species,
-                 const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant, uint8_t level, uint32_t experience,
-                 uint32_t uid, Library::Gender gender, uint8_t coloring,
+                 const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant, level_int_t level,
+                 uint32_t experience, uint32_t uid, Library::Gender gender, uint8_t coloring,
                  const ArbUt::BorrowedPtr<const Library::Item> heldItem, const std::string& nickname,
                  const Library::TalentIndex& talent, const std::vector<LearnedAttack*>& attacks,
                  bool allowedExperienceGain = true);
@@ -88,7 +89,7 @@ namespace CreatureLib::Battling {
         virtual void ChangeSpecies(const ArbUt::BorrowedPtr<const Library::CreatureSpecies>& species,
                                    const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant);
         virtual void ChangeVariant(const ArbUt::BorrowedPtr<const Library::SpeciesVariant>& variant);
-        inline uint8_t GetLevel() const noexcept { return _level; }
+        inline level_int_t GetLevel() const noexcept { return _level; }
         inline uint32_t GetExperience() const noexcept { return _experience; }
         inline uint32_t GetUniqueIdentifier() const noexcept { return _uniqueIdentifier; }
         inline Library::Gender GetGender() const noexcept { return _gender; }
diff --git a/src/Defines.hpp b/src/Defines.hpp
new file mode 100644
index 0000000..6dcece9
--- /dev/null
+++ b/src/Defines.hpp
@@ -0,0 +1,16 @@
+#ifndef CREATURELIB_DEFINES_HPP
+#define CREATURELIB_DEFINES_HPP
+
+#include <cstdint>
+
+#if LEVEL_U8
+typedef uint8_t level_int_t;
+#elif LEVEL_U16
+typedef uint16_t level_int_t;
+#elif LEVEL_U32
+typedef uint32_t level_int_t;
+#elif LEVEL_U64
+typedef uint64_t level_int_t;
+#endif
+
+#endif // CREATURELIB_DEFINES_HPP
diff --git a/src/Library/CreatureData/LearnableAttacks.cpp b/src/Library/CreatureData/LearnableAttacks.cpp
index 6016fe5..863cceb 100644
--- a/src/Library/CreatureData/LearnableAttacks.cpp
+++ b/src/Library/CreatureData/LearnableAttacks.cpp
@@ -2,7 +2,7 @@
 
 using namespace CreatureLib::Library;
 
-void LearnableAttacks::AddLevelAttack(uint8_t level, ArbUt::BorrowedPtr<const AttackData> attack) {
+void LearnableAttacks::AddLevelAttack(level_int_t level, ArbUt::BorrowedPtr<const AttackData> attack) {
     if (_learnedByLevel.Has(level)) {
         _learnedByLevel[level].Append(attack);
     } else {
diff --git a/src/Library/CreatureData/LearnableAttacks.hpp b/src/Library/CreatureData/LearnableAttacks.hpp
index 94eb454..e905ec4 100644
--- a/src/Library/CreatureData/LearnableAttacks.hpp
+++ b/src/Library/CreatureData/LearnableAttacks.hpp
@@ -7,6 +7,7 @@
 #include <Arbutils/Memory/BorrowedPtr.hpp>
 #include <Arbutils/Random.hpp>
 #include <unordered_map>
+#include "../../Defines.hpp"
 #include "../Attacks/AttackData.hpp"
 
 namespace CreatureLib::Library {
@@ -22,7 +23,7 @@ namespace CreatureLib::Library {
 
         virtual ~LearnableAttacks() = default;
 
-        void AddLevelAttack(uint8_t level, ArbUt::BorrowedPtr<const AttackData> attack);
+        void AddLevelAttack(level_int_t level, ArbUt::BorrowedPtr<const AttackData> attack);
 
         inline bool HasAttacksForLevel(uint8_t level) const noexcept { return _learnedByLevel.Has(level); }
         inline const ArbUt::List<ArbUt::BorrowedPtr<const AttackData>>& GetAttacksForLevel(uint8_t level) const {
diff --git a/src/Library/GrowthRates/ExternGrowthRate.hpp b/src/Library/GrowthRates/ExternGrowthRate.hpp
index 3e2a603..bb885e0 100644
--- a/src/Library/GrowthRates/ExternGrowthRate.hpp
+++ b/src/Library/GrowthRates/ExternGrowthRate.hpp
@@ -2,21 +2,22 @@
 #define CREATURELIB_EXTERNGROWTHRATE_HPP
 
 #include <Arbutils/Assert.hpp>
+#include "../../Defines.hpp"
 #include "GrowthRate.hpp"
 namespace CreatureLib::Library {
     class ExternGrowthRate : public GrowthRate {
-        uint8_t (*_calcLevel)(uint32_t experience);
-        uint32_t (*_calcExperience)(uint8_t level);
+        level_int_t (*_calcLevel)(uint32_t experience);
+        uint32_t (*_calcExperience)(level_int_t level);
 
     public:
-        inline ExternGrowthRate(uint8_t (*calcLevel)(uint32_t), uint32_t (*calcExperience)(uint8_t level))
+        inline ExternGrowthRate(level_int_t (*calcLevel)(uint32_t), uint32_t (*calcExperience)(level_int_t level))
             : _calcLevel(calcLevel), _calcExperience(calcExperience) {
             AssertNotNull(calcLevel)
             AssertNotNull(calcExperience)
         }
 
-        uint8_t CalculateLevel(uint32_t experience) const override { return _calcLevel(experience); }
-        uint32_t CalculateExperience(uint8_t level) const override { return _calcExperience(level); }
+        level_int_t CalculateLevel(uint32_t experience) const override { return _calcLevel(experience); }
+        uint32_t CalculateExperience(level_int_t level) const override { return _calcExperience(level); }
     };
 }
 
diff --git a/src/Library/GrowthRates/GrowthRate.hpp b/src/Library/GrowthRates/GrowthRate.hpp
index b05a4c4..6129ac3 100644
--- a/src/Library/GrowthRates/GrowthRate.hpp
+++ b/src/Library/GrowthRates/GrowthRate.hpp
@@ -2,14 +2,15 @@
 #define CREATURELIB_GROWTHRATE_HPP
 
 #include <cstdint>
+#include "../../Defines.hpp"
 
 namespace CreatureLib::Library {
     class GrowthRate {
     public:
         virtual ~GrowthRate() = default;
 
-        [[nodiscard]] virtual uint8_t CalculateLevel(uint32_t experience) const = 0;
-        [[nodiscard]] virtual uint32_t CalculateExperience(uint8_t level) const = 0;
+        [[nodiscard]] virtual level_int_t CalculateLevel(uint32_t experience) const = 0;
+        [[nodiscard]] virtual uint32_t CalculateExperience(level_int_t level) const = 0;
     };
 }
 
diff --git a/src/Library/GrowthRates/GrowthRateLibrary.cpp b/src/Library/GrowthRates/GrowthRateLibrary.cpp
index 8af9622..df6fadc 100644
--- a/src/Library/GrowthRates/GrowthRateLibrary.cpp
+++ b/src/Library/GrowthRates/GrowthRateLibrary.cpp
@@ -19,7 +19,7 @@ uint8_t CreatureLib::Library::GrowthRateLibrary::CalculateLevel(uint32_t hash, u
 }
 
 uint32_t CreatureLib::Library::GrowthRateLibrary::CalculateExperience(const ArbUt::BasicStringView& growthRate,
-                                                                      uint8_t level) const {
+                                                                      level_int_t level) const {
     auto find = _growthRates.find(growthRate);
     if (find == _growthRates.end()) {
         THROW("Invalid growth rate was requested.");
@@ -27,7 +27,7 @@ uint32_t CreatureLib::Library::GrowthRateLibrary::CalculateExperience(const ArbU
     return find->second->CalculateExperience(level);
 }
 
-uint32_t CreatureLib::Library::GrowthRateLibrary::CalculateExperience(uint32_t hash, uint8_t level) const {
+uint32_t CreatureLib::Library::GrowthRateLibrary::CalculateExperience(uint32_t hash, level_int_t level) const {
     auto find = _growthRates.find(hash);
     if (find == _growthRates.end()) {
         THROW("Invalid growth rate was requested.");
diff --git a/src/Library/GrowthRates/GrowthRateLibrary.hpp b/src/Library/GrowthRates/GrowthRateLibrary.hpp
index a3bf858..e23fe28 100644
--- a/src/Library/GrowthRates/GrowthRateLibrary.hpp
+++ b/src/Library/GrowthRates/GrowthRateLibrary.hpp
@@ -21,8 +21,8 @@ namespace CreatureLib::Library {
 
         [[nodiscard]] uint8_t CalculateLevel(const ArbUt::BasicStringView& growthRate, uint32_t experience) const;
         [[nodiscard]] uint8_t CalculateLevel(uint32_t hash, uint32_t experience) const;
-        [[nodiscard]] uint32_t CalculateExperience(const ArbUt::BasicStringView& growthRate, uint8_t level) const;
-        [[nodiscard]] uint32_t CalculateExperience(uint32_t hash, uint8_t level) const;
+        [[nodiscard]] uint32_t CalculateExperience(const ArbUt::BasicStringView& growthRate, level_int_t level) const;
+        [[nodiscard]] uint32_t CalculateExperience(uint32_t hash, level_int_t level) const;
 
         void AddGrowthRate(uint32_t hash, GrowthRate* rate);
         void AddGrowthRate(const ArbUt::StringView& name, GrowthRate* rate);
diff --git a/src/Library/GrowthRates/LookupGrowthRate.hpp b/src/Library/GrowthRates/LookupGrowthRate.hpp
index d7e43f8..24558f7 100644
--- a/src/Library/GrowthRates/LookupGrowthRate.hpp
+++ b/src/Library/GrowthRates/LookupGrowthRate.hpp
@@ -12,8 +12,8 @@ namespace CreatureLib::Library {
     public:
         LookupGrowthRate(const ArbUt::List<uint32_t>& experience) : _experience(experience) {}
 
-        uint8_t CalculateLevel(uint32_t experience) const override {
-            for (uint8_t i = 0; i < _experience.Count(); i++) {
+        level_int_t CalculateLevel(uint32_t experience) const override {
+            for (level_int_t i = 0; i < _experience.Count(); i++) {
                 if (_experience[i] > experience) {
                     return i;
                 }
@@ -21,7 +21,7 @@ namespace CreatureLib::Library {
             return _experience[_experience.Count() - 1];
         }
 
-        uint32_t CalculateExperience(uint8_t level) const override { return _experience[level - 1]; }
+        uint32_t CalculateExperience(level_int_t level) const override { return _experience[level - 1]; }
     };
 }
 
diff --git a/src/Library/LibrarySettings.hpp b/src/Library/LibrarySettings.hpp
index 4434f95..7822ba6 100644
--- a/src/Library/LibrarySettings.hpp
+++ b/src/Library/LibrarySettings.hpp
@@ -2,17 +2,18 @@
 #define CREATURELIB_LIBRARYSETTINGS_HPP
 
 #include <cstdint>
+#include "../Defines.hpp"
 
 namespace CreatureLib::Library {
     class LibrarySettings {
-        uint8_t _maximalLevel;
+        level_int_t _maximalLevel;
         uint8_t _maximalAttacks;
 
     public:
-        LibrarySettings(uint8_t maximalLevel, uint8_t maximalAttacks)
+        LibrarySettings(level_int_t maximalLevel, uint8_t maximalAttacks)
             : _maximalLevel(maximalLevel), _maximalAttacks(maximalAttacks) {}
 
-        inline uint8_t GetMaximalLevel() const noexcept { return _maximalLevel; }
+        inline level_int_t GetMaximalLevel() const noexcept { return _maximalLevel; }
 
         inline uint8_t GetMaximalAttacks() const noexcept { return _maximalAttacks; }
     };