diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 072e5aec3..2b6824d1c 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -473,6 +473,7 @@ add_devilutionx_object_library(libdevilutionx_items
 )
 target_link_dependencies(libdevilutionx_items PUBLIC
   DevilutionX::SDL
+  sol2::sol2
   tl
   libdevilutionx_headless_mode
   libdevilutionx_sound
diff --git a/Source/itemdat.cpp b/Source/itemdat.cpp
index 5d5fca31d..44f07e84a 100644
--- a/Source/itemdat.cpp
+++ b/Source/itemdat.cpp
@@ -10,10 +10,12 @@
 #include <vector>
 
 #include <expected.hpp>
+#include <fmt/format.h>
 
 #include "data/file.hpp"
 #include "data/iterators.hpp"
 #include "data/record_reader.hpp"
+#include "lua/lua_global.hpp"
 #include "spelldat.h"
 #include "utils/str_cat.hpp"
 
@@ -25,6 +27,9 @@ std::vector<ItemData> AllItemsList;
 /** Contains the data related to each unique item ID. */
 std::vector<UniqueItem> UniqueItems;
 
+/** Contains unique item mapping IDs, with unique item indices assigned to them. This is used for loading saved games. */
+ankerl::unordered_dense::map<int32_t, int32_t> UniqueItemMappingIdsToIndices;
+
 /** Contains the data related to each item prefix. */
 std::vector<PLStruct> ItemPrefixes;
 
@@ -559,14 +564,14 @@ void ReadItemPower(RecordReader &reader, std::string_view fieldName, ItemPower &
 	reader.readOptionalInt(StrCat(fieldName, ".value2"), power.param2);
 }
 
-void LoadUniqueItemDat()
+} // namespace
+
+void LoadUniqueItemDatFromFile(DataFile &dataFile, std::string_view filename, int32_t baseMappingId)
 {
-	const std::string_view filename = "txtdata\\items\\unique_itemdat.tsv";
-	DataFile dataFile = DataFile::loadOrDie(filename);
 	dataFile.skipHeaderOrDie(filename);
 
-	UniqueItems.clear();
-	UniqueItems.reserve(dataFile.numRecords());
+	int32_t currentMappingId = baseMappingId;
+	UniqueItems.reserve(UniqueItems.size() + dataFile.numRecords());
 	for (DataFileRecord record : dataFile) {
 		RecordReader reader { record, filename };
 		UniqueItem &item = UniqueItems.emplace_back();
@@ -583,10 +588,32 @@ void LoadUniqueItemDat()
 				break;
 			ReadItemPower(reader, StrCat("power", i), item.powers[item.UINumPL++]);
 		}
+
+		item.mappingId = currentMappingId;
+		const auto [it, inserted] = UniqueItemMappingIdsToIndices.emplace(item.mappingId, static_cast<int32_t>(UniqueItems.size()) - 1);
+		if (!inserted) {
+			DisplayFatalErrorAndExit("Adding Unique Item Failed", fmt::format("A unique item already exists for mapping ID {}.", item.mappingId));
+		}
+
+		++currentMappingId;
 	}
 	UniqueItems.shrink_to_fit();
 }
 
+namespace {
+
+void LoadUniqueItemDat()
+{
+	const std::string_view filename = "txtdata\\items\\unique_itemdat.tsv";
+	DataFile dataFile = DataFile::loadOrDie(filename);
+
+	UniqueItems.clear();
+	UniqueItemMappingIdsToIndices.clear();
+	LoadUniqueItemDatFromFile(dataFile, filename, 0);
+
+	LuaEvent("UniqueItemDataLoaded");
+}
+
 void LoadItemAffixesDat(std::string_view filename, std::vector<PLStruct> &out)
 {
 	DataFile dataFile = DataFile::loadOrDie(filename);
diff --git a/Source/itemdat.h b/Source/itemdat.h
index ae747ae91..620548e70 100644
--- a/Source/itemdat.h
+++ b/Source/itemdat.h
@@ -9,11 +9,15 @@
 #include <string_view>
 #include <vector>
 
+#include <ankerl/unordered_dense.h>
+
 #include "objdat.h"
 #include "spelldat.h"
 
 namespace devilution {
 
+class DataFile;
+
 /** @todo add missing values and apply */
 enum _item_indexes : int16_t { // TODO defines all indexes in AllItemsList
 	IDI_GOLD,
@@ -637,13 +641,16 @@ struct UniqueItem {
 	uint8_t UINumPL;
 	int UIValue;
 	ItemPower powers[6];
+	int32_t mappingId;
 };
 
 extern DVL_API_FOR_TEST std::vector<ItemData> AllItemsList;
 extern std::vector<PLStruct> ItemPrefixes;
 extern std::vector<PLStruct> ItemSuffixes;
 extern DVL_API_FOR_TEST std::vector<UniqueItem> UniqueItems;
+extern ankerl::unordered_dense::map<int32_t, int32_t> UniqueItemMappingIdsToIndices;
 
+void LoadUniqueItemDatFromFile(DataFile &dataFile, std::string_view filename, int32_t baseMappingId);
 void LoadItemData();
 
 } // namespace devilution
diff --git a/Source/items.h b/Source/items.h
index 82202f351..70bf4e0e0 100644
--- a/Source/items.h
+++ b/Source/items.h
@@ -43,7 +43,7 @@ enum item_quality : uint8_t {
 	ITEM_QUALITY_UNIQUE,
 };
 
-enum _unique_items : int8_t {
+enum _unique_items : int32_t {
 	UITEM_CLEAVER,
 	UITEM_SKCROWN,
 	UITEM_INFRARING,
diff --git a/Source/loadsave.cpp b/Source/loadsave.cpp
index 5a410752d..9092e7b27 100644
--- a/Source/loadsave.cpp
+++ b/Source/loadsave.cpp
@@ -263,7 +263,7 @@ struct LevelConversionData {
 	MonsterConversionData monsterConversionData[MaxMonsters];
 };
 
-void LoadItemData(LoadHelper &file, Item &item)
+[[nodiscard]] bool LoadItemData(LoadHelper &file, Item &item)
 {
 	item._iSeed = file.NextLE<uint32_t>();
 	item._iCreateInfo = file.NextLE<uint16_t>();
@@ -321,7 +321,20 @@ void LoadItemData(LoadHelper &file, Item &item)
 	item._iSplLvlAdd = file.NextLE<int8_t>();
 	item._iRequest = file.NextBool8();
 	file.Skip(2); // Alignment
-	item._iUid = file.NextLE<int32_t>();
+
+	const int32_t uniqueMappingId = file.NextLE<int32_t>();
+	if (item._iMagical == ITEM_QUALITY_UNIQUE) {
+		const auto findIt = UniqueItemMappingIdsToIndices.find(uniqueMappingId);
+		if (findIt == UniqueItemMappingIdsToIndices.end()) {
+			return false;
+		}
+
+		const int uniqueIndex = findIt->second;
+		item._iUid = uniqueIndex;
+	} else {
+		item._iUid = 0;
+	}
+
 	item._iFMinDam = file.NextLE<int32_t>();
 	item._iFMaxDam = file.NextLE<int32_t>();
 	item._iLMinDam = file.NextLE<int32_t>();
@@ -352,11 +365,18 @@ void LoadItemData(LoadHelper &file, Item &item)
 	else
 		item._iDamAcFlags = ItemSpecialEffectHf::None;
 	UpdateHellfireFlag(item, item._iIName);
+
+	return true;
 }
 
 void LoadAndValidateItemData(LoadHelper &file, Item &item)
 {
-	LoadItemData(file, item);
+	const bool success = LoadItemData(file, item);
+	if (!success) {
+		item.clear();
+		return;
+	}
+
 	RemoveInvalidItem(item);
 }
 
@@ -1052,7 +1072,11 @@ void LoadMatchingItems(LoadHelper &file, const Player &player, const int n, Item
 
 	for (int i = 0; i < n; i++) {
 		Item &unpackedItem = pItem[i];
-		LoadItemData(file, heroItem);
+		const bool success = LoadItemData(file, heroItem);
+		if (!success) {
+			heroItem.clear();
+			unpackedItem = Item();
+		}
 		if (unpackedItem.isEmpty() || heroItem.isEmpty())
 			continue;
 		if (unpackedItem._iSeed != heroItem._iSeed)
@@ -1190,7 +1214,7 @@ void SaveItem(SaveHelper &file, const Item &item)
 	file.WriteLE<int8_t>(item._iSplLvlAdd);
 	file.WriteLE<int8_t>(item._iRequest ? 1 : 0);
 	file.Skip(2); // Alignment
-	file.WriteLE<int32_t>(item._iUid);
+	file.WriteLE<int32_t>(UniqueItems[item._iUid].mappingId);
 	file.WriteLE<int32_t>(item._iFMinDam);
 	file.WriteLE<int32_t>(item._iFMaxDam);
 	file.WriteLE<int32_t>(item._iLMinDam);
diff --git a/Source/lua/modules/items.cpp b/Source/lua/modules/items.cpp
index a2e34acb4..999e3b6c8 100644
--- a/Source/lua/modules/items.cpp
+++ b/Source/lua/modules/items.cpp
@@ -2,8 +2,11 @@
 
 #include <string_view>
 
+#include <fmt/format.h>
 #include <sol/sol.hpp>
 
+#include "data/file.hpp"
+#include "itemdat.h"
 #include "items.h"
 #include "lua/metadoc.hpp"
 #include "player.h"
@@ -451,6 +454,12 @@ void RegisterItemSpecialEffectHfEnum(sol::state_view &lua)
 	    });
 }
 
+void AddUniqueItemDataFromTsv(const std::string_view path, const int32_t baseMappingId)
+{
+	DataFile dataFile = DataFile::loadOrDie(path);
+	LoadUniqueItemDatFromFile(dataFile, path, baseMappingId);
+}
+
 } // namespace
 
 sol::table LuaItemModule(sol::state_view &lua)
@@ -468,6 +477,8 @@ sol::table LuaItemModule(sol::state_view &lua)
 
 	sol::table table = lua.create_table();
 
+	LuaSetDocFn(table, "addUniqueItemDataFromTsv", "(path: string, baseMappingId: number)", AddUniqueItemDataFromTsv);
+
 	return table;
 }
 
diff --git a/assets/lua/devilutionx/events.lua b/assets/lua/devilutionx/events.lua
index 4df5a9787..8bf4afa35 100644
--- a/assets/lua/devilutionx/events.lua
+++ b/assets/lua/devilutionx/events.lua
@@ -44,6 +44,10 @@ local events = {
   LoadModsComplete = CreateEvent(),
   __doc_LoadModsComplete = "Called after all mods have been loaded.",
 
+  ---Called after the unique item data TSV file has been loaded.
+  UniqueItemDataLoaded = CreateEvent(),
+  __doc_UniqueItemDataLoaded = "Called after the unique item data TSV file has been loaded.",
+
   ---Called after the monster data TSV file has been loaded.
   MonsterDataLoaded = CreateEvent(),
   __doc_MonsterDataLoaded = "Called after the monster data TSV file has been loaded.",