diff --git a/src/content/Content.cpp b/src/content/Content.cpp
index 5ee68859..c0093491 100644
--- a/src/content/Content.cpp
+++ b/src/content/Content.cpp
@@ -35,13 +35,15 @@ Content::Content(
     UptrsMap<std::string, BlockMaterial> blockMaterials,
     UptrsMap<std::string, rigging::SkeletonConfig> skeletons,
     ResourceIndicesSet resourceIndices,
-    dv::value defaults
+    dv::value defaults,
+    std::unordered_map<std::string, int> tags
 )
     : indices(std::move(indices)),
       packs(std::move(packs)),
       blockMaterials(std::move(blockMaterials)),
       skeletons(std::move(skeletons)),
       defaults(std::move(defaults)),
+      tags(std::move(tags)),
       blocks(std::move(blocks)),
       items(std::move(items)),
       entities(std::move(entities)),
diff --git a/src/content/Content.hpp b/src/content/Content.hpp
index 81e816b6..599d50fe 100644
--- a/src/content/Content.hpp
+++ b/src/content/Content.hpp
@@ -176,6 +176,7 @@ class Content {
     UptrsMap<std::string, BlockMaterial> blockMaterials;
     UptrsMap<std::string, rigging::SkeletonConfig> skeletons;
     dv::value defaults = nullptr;
+    std::unordered_map<std::string, int> tags;
 public:
     ContentUnitDefs<Block> blocks;
     ContentUnitDefs<ItemDef> items;
@@ -195,7 +196,8 @@ public:
         UptrsMap<std::string, BlockMaterial> blockMaterials,
         UptrsMap<std::string, rigging::SkeletonConfig> skeletons,
         ResourceIndicesSet resourceIndices,
-        dv::value defaults
+        dv::value defaults,
+        std::unordered_map<std::string, int> tags
     );
     ~Content();
 
@@ -211,6 +213,14 @@ public:
         return defaults;
     }
 
+    int getTagIndex(const std::string& tag) const {
+        const auto& found = tags.find(tag);
+        if (found == tags.end()) {
+            return -1;
+        }
+        return found->second;
+    }
+
     const rigging::SkeletonConfig* getSkeleton(const std::string& id) const;
     const rigging::SkeletonConfig& requireSkeleton(const std::string& id) const;
     const BlockMaterial* findBlockMaterial(const std::string& id) const;
diff --git a/src/content/ContentBuilder.cpp b/src/content/ContentBuilder.cpp
index 448adc27..84f2e688 100644
--- a/src/content/ContentBuilder.cpp
+++ b/src/content/ContentBuilder.cpp
@@ -29,7 +29,7 @@ std::unique_ptr<Content> ContentBuilder::build() {
         def.rt.id = blockDefsIndices.size();
         def.rt.emissive = *reinterpret_cast<uint32_t*>(def.emission);
         for (const auto& tag : def.tags) {
-            def.rt.tags.push_back(tags.add(tag));
+            def.rt.tags.insert(tags.add(tag));
         }
 
         if (def.variants) {
@@ -96,7 +96,8 @@ std::unique_ptr<Content> ContentBuilder::build() {
         std::move(blockMaterials),
         std::move(skeletons),
         std::move(resourceIndices),
-        std::move(defaults)
+        std::move(defaults),
+        std::move(tags.map)
     );
 
     // Now, it's time to resolve foreign keys
diff --git a/src/items/ItemDef.hpp b/src/items/ItemDef.hpp
index 52ebd835..40e052b9 100644
--- a/src/items/ItemDef.hpp
+++ b/src/items/ItemDef.hpp
@@ -3,6 +3,7 @@
 #include <glm/glm.hpp>
 #include <string>
 #include <vector>
+#include <set>
 
 #include "data/dv.hpp"
 #include "typedefs.hpp"
@@ -73,7 +74,7 @@ struct ItemDef {
         ItemFuncsSet funcsset {};
         bool emissive = false;
 
-        std::vector<int> tags;
+        std::set<int> tags;
     } rt {};
 
     ItemDef(const std::string& name);
diff --git a/src/logic/scripting/lua/libs/libblock.cpp b/src/logic/scripting/lua/libs/libblock.cpp
index 52e2931c..fd0496fe 100644
--- a/src/logic/scripting/lua/libs/libblock.cpp
+++ b/src/logic/scripting/lua/libs/libblock.cpp
@@ -698,6 +698,15 @@ static int l_reload_script(lua::State* L) {
     return 0;
 }
 
+static int l_has_tag(lua::State* L) {
+    if (auto def = require_block(L)) {
+        auto tag = lua::require_string(L, 2);
+        const auto& tags = def->rt.tags;
+        return lua::pushboolean(L, tags.find(content->getTagIndex(tag)) != tags.end());
+    }
+    return 0;
+}
+
 const luaL_Reg blocklib[] = {
     {"index", lua::wrap<l_index>},
     {"name", lua::wrap<l_get_def>},
@@ -737,5 +746,6 @@ const luaL_Reg blocklib[] = {
     {"get_field", lua::wrap<l_get_field>},
     {"set_field", lua::wrap<l_set_field>},
     {"reload_script", lua::wrap<l_reload_script>},
+    {"has_tag", lua::wrap<l_has_tag>},
     {NULL, NULL}
 };
diff --git a/src/logic/scripting/lua/libs/libitem.cpp b/src/logic/scripting/lua/libs/libitem.cpp
index d70a7211..b26e524c 100644
--- a/src/logic/scripting/lua/libs/libitem.cpp
+++ b/src/logic/scripting/lua/libs/libitem.cpp
@@ -108,6 +108,15 @@ static int l_reload_script(lua::State* L) {
     return 0;
 }
 
+static int l_has_tag(lua::State* L) {
+    if (auto def = get_item_def(L, 1)) {
+        auto tag = lua::require_string(L, 2);
+        const auto& tags = def->rt.tags;
+        return lua::pushboolean(L, tags.find(content->getTagIndex(tag)) != tags.end());
+    }
+    return 0;
+}
+
 const luaL_Reg itemlib[] = {
     {"index", lua::wrap<l_index>},
     {"name", lua::wrap<l_name>},
@@ -121,5 +130,6 @@ const luaL_Reg itemlib[] = {
     {"emission", lua::wrap<l_emission>},
     {"uses", lua::wrap<l_uses>},
     {"reload_script", lua::wrap<l_reload_script>},
+    {"has_tag", lua::wrap<l_has_tag>},
     {NULL, NULL}
 };
diff --git a/src/voxels/Block.hpp b/src/voxels/Block.hpp
index 3d5a86a9..707f6b8b 100644
--- a/src/voxels/Block.hpp
+++ b/src/voxels/Block.hpp
@@ -4,6 +4,7 @@
 #include <string>
 #include <vector>
 #include <array>
+#include <set>
 
 #include "data/dv.hpp"
 #include "maths/UVRegion.hpp"
@@ -288,7 +289,7 @@ public:
 
         blockid_t surfaceReplacement = 0;
 
-        std::vector<int> tags;
+        std::set<int> tags;
     } rt {};
 
     Block(const std::string& name);