diff --git a/Runtime/CStateManager.cpp b/Runtime/CStateManager.cpp
index d37afdc8d..24d06449f 100644
--- a/Runtime/CStateManager.cpp
+++ b/Runtime/CStateManager.cpp
@@ -2004,7 +2004,7 @@ void CStateManager::UpdateAreaSounds() {
       occState = area.GetOcclusionState();
     }
     if (occState == CGameArea::EOcclusionState::Visible) {
-      areas.push_back(area.GetAreaId());
+      areas.push_back(area.GetAreaIndex());
     }
   }
   CSfxManager::SetActiveAreas(areas);
diff --git a/Runtime/Character/CActorLights.cpp b/Runtime/Character/CActorLights.cpp
index 70530aebf..3365ae2f1 100644
--- a/Runtime/Character/CActorLights.cpp
+++ b/Runtime/Character/CActorLights.cpp
@@ -183,7 +183,7 @@ bool CActorLights::BuildAreaLightList(const CStateManager& mgr, const CGameArea&
   }
 
   zeus::CVector3f vec;
-  if (!x298_24_dirty && x294_aid == area.GetAreaId()) {
+  if (!x298_24_dirty && x294_aid == area.GetAreaIndex()) {
     /* Early return if not ready for update */
     if (mgr.GetInputFrameIdx() - x2a4_lastUpdateFrame < x2a8_areaUpdateFramePeriod)
       return false;
@@ -193,7 +193,7 @@ bool CActorLights::BuildAreaLightList(const CStateManager& mgr, const CGameArea&
         return false;
     x2c0_lastActorPos = vec;
   } else {
-    if (x294_aid != area.GetAreaId())
+    if (x294_aid != area.GetAreaIndex())
       x2d8_brightLightIdx = -1;
     x2a4_lastUpdateFrame = sFrameSchedulerCount + mgr.GetInputFrameIdx();
     vec = aabb.center() + x2ac_actorPosBias;
@@ -203,7 +203,7 @@ bool CActorLights::BuildAreaLightList(const CStateManager& mgr, const CGameArea&
   /* Reset lighting state */
   x2d4_worldLightingLevel = worldLightingLevel;
   x298_24_dirty = false;
-  x294_aid = area.GetAreaId();
+  x294_aid = area.GetAreaIndex();
   x29c_shadowLightArrIdx = -1;
   x288_ambientColor = zeus::skClear;
 
diff --git a/Runtime/World/CGameArea.cpp b/Runtime/World/CGameArea.cpp
index 786c254cc..696ed5b22 100644
--- a/Runtime/World/CGameArea.cpp
+++ b/Runtime/World/CGameArea.cpp
@@ -306,7 +306,7 @@ CDummyGameArea::CDummyGameArea(CInputStream& in, int idx, int mlvlVersion) {
   aabb.readBoundingBoxBig(in);
   xc_mrea = in.readUint32Big();
   if (mlvlVersion > 15)
-    x10_areaId = in.readUint32Big();
+    x10_areaId = CAssetId(in);
 
   u32 attachAreaCount = in.readUint32Big();
   x44_attachedAreaIndices.reserve(attachAreaCount);
@@ -332,7 +332,7 @@ std::pair<std::unique_ptr<u8[]>, s32> CDummyGameArea::IGetScriptingMemoryAlways(
   return GetScriptingMemoryAlways(*this);
 }
 
-TAreaId CDummyGameArea::IGetAreaId() const { return x10_areaId; }
+CAssetId CDummyGameArea::IGetAreaId() const { return x10_areaId; }
 
 CAssetId CDummyGameArea::IGetAreaAssetId() const { return xc_mrea; }
 
@@ -354,9 +354,9 @@ CGameArea::CGameArea(CInputStream& in, int idx, int mlvlVersion) : x4_selfIdx(id
 
   x84_mrea = in.readUint32Big();
   if (mlvlVersion > 15)
-    x88_areaId = in.readInt32Big();
+    x88_areaId = CAssetId(in);
   else
-    x88_areaId = -1;
+    x88_areaId = CAssetId();
 
   const u32 attachedCount = in.readUint32Big();
   x8c_attachedAreaIndices.reserve(attachedCount);
@@ -782,7 +782,7 @@ bool CGameArea::Invalidate(CStateManager* mgr) {
   }
 
   if (mgr)
-    mgr->PrepareAreaUnload(GetAreaId());
+    mgr->PrepareAreaUnload(GetAreaIndex());
 
 #if 0
     dword_805a8eb0 -= GetPostConstructedSize();
@@ -797,7 +797,7 @@ bool CGameArea::Invalidate(CStateManager* mgr) {
   KillmAreaData();
   ClearTokenList();
   if (mgr)
-    mgr->AreaUnloaded(GetAreaId());
+    mgr->AreaUnloaded(GetAreaIndex());
 
   return true;
 }
diff --git a/Runtime/World/CGameArea.hpp b/Runtime/World/CGameArea.hpp
index 4d9f7c1ca..e6e2c1a43 100644
--- a/Runtime/World/CGameArea.hpp
+++ b/Runtime/World/CGameArea.hpp
@@ -47,7 +47,7 @@ class CDummyGameArea final : public IGameArea {
   int x4_mlvlVersion;
   CAssetId x8_nameSTRG;
   CAssetId xc_mrea;
-  TAreaId x10_areaId;
+  CAssetId x10_areaId;
   zeus::CTransform x14_transform;
   std::vector<u16> x44_attachedAreaIndices;
   std::vector<Dock> x54_docks;
@@ -56,7 +56,7 @@ public:
   CDummyGameArea(CInputStream& in, int idx, int mlvlVersion);
 
   std::pair<std::unique_ptr<u8[]>, s32> IGetScriptingMemoryAlways() const override;
-  TAreaId IGetAreaId() const override;
+  CAssetId IGetAreaId() const override;
   CAssetId IGetAreaAssetId() const override;
   bool IIsActive() const override;
   TAreaId IGetAttachedAreaId(int) const override;
@@ -278,8 +278,8 @@ public:
   void SetLoadPauseState(bool paused);
 
   std::pair<std::unique_ptr<u8[]>, s32> IGetScriptingMemoryAlways() const override;
-  TAreaId GetAreaId() const { return x4_selfIdx; }
-  TAreaId IGetAreaId() const override { return x4_selfIdx; }
+  CAssetId GetAreaIndex() const { return x4_selfIdx; }
+  CAssetId IGetAreaId() const override { return x88_areaId; }
   CAssetId IGetAreaAssetId() const override { return x84_mrea; }
   bool IIsActive() const override;
   TAreaId IGetAttachedAreaId(int) const override;
diff --git a/Runtime/World/CMorphBallShadow.cpp b/Runtime/World/CMorphBallShadow.cpp
index 0d60b55e0..e9c3886e4 100644
--- a/Runtime/World/CMorphBallShadow.cpp
+++ b/Runtime/World/CMorphBallShadow.cpp
@@ -16,7 +16,7 @@ void CMorphBallShadow::GatherAreas(const CStateManager& mgr) {
     if (area.IsPostConstructed())
       occState = area.GetPostConstructed()->x10dc_occlusionState;
     if (occState == CGameArea::EOcclusionState::Visible)
-      x18_areas.push_back(area.GetAreaId());
+      x18_areas.push_back(area.GetAreaIndex());
   }
 }
 
@@ -105,7 +105,7 @@ bool CMorphBallShadow::AreasValid(const CStateManager& mgr) const {
       continue;
     if (it == x18_areas.end())
       return false;
-    if (*it != area.GetAreaId())
+    if (*it != area.GetAreaIndex())
       return false;
     ++it;
   }
diff --git a/Runtime/World/CScriptDoor.cpp b/Runtime/World/CScriptDoor.cpp
index 78384e62b..a0ec4b435 100644
--- a/Runtime/World/CScriptDoor.cpp
+++ b/Runtime/World/CScriptDoor.cpp
@@ -364,7 +364,7 @@ CScriptDoor::EDoorOpenCondition CScriptDoor::GetDoorOpenCondition(CStateManager&
   }
 
   for (const CGameArea& aliveArea : *world) {
-    if (aliveArea.GetAreaId() == area->GetAreaId()) {
+    if (aliveArea.GetAreaIndex() == area->GetAreaIndex()) {
       continue;
     }
 
diff --git a/Runtime/World/IGameArea.hpp b/Runtime/World/IGameArea.hpp
index 9eb2c870b..9dd8a7579 100644
--- a/Runtime/World/IGameArea.hpp
+++ b/Runtime/World/IGameArea.hpp
@@ -49,7 +49,7 @@ public:
   };
 
   virtual std::pair<std::unique_ptr<u8[]>, s32> IGetScriptingMemoryAlways() const = 0;
-  virtual TAreaId IGetAreaId() const = 0;
+  virtual CAssetId IGetAreaId() const = 0;
   virtual CAssetId IGetAreaAssetId() const = 0;
   virtual bool IIsActive() const = 0;
   virtual TAreaId IGetAttachedAreaId(int) const = 0;