diff --git a/core/HalfLife2.cpp b/core/HalfLife2.cpp
index 56437402..50203321 100644
--- a/core/HalfLife2.cpp
+++ b/core/HalfLife2.cpp
@@ -37,10 +37,14 @@
 #include "sm_stringutil.h"
 #include "GameConfigs.h"
 #include <compat_wrappers.h>
+#include <Logger.h>
 
 CHalfLife2 g_HL2;
 ConVar *sv_lan = NULL;
 
+static void *g_EntList = NULL;
+static int entInfoOffset = -1;
+
 namespace SourceHook
 {
 	template<>
@@ -123,6 +127,51 @@ void CHalfLife2::OnSourceModAllInitialized()
 	g_ShareSys.AddInterface(NULL, this);
 }
 
+void CHalfLife2::OnSourceModAllInitialized_Post()
+{
+	char *addr = NULL;
+#ifdef PLATFORM_WINDOWS
+	int offset;
+
+	/* gEntList and/or g_pEntityList */
+	if (!g_pGameConf->GetMemSig("LevelShutdown", (void **)&addr))
+	{
+		g_Logger.LogError("Logical Entities not supported by this mod (LevelShutdown) - Reverting to networkable entities only");
+		return;
+	}
+	if (!addr)
+	{
+		g_Logger.LogError("Failed lookup of LevelShutdown - Reverting to networkable entities only");
+		return;
+	}
+	if (!g_pGameConf->GetOffset("gEntList", &offset))
+	{
+		g_Logger.LogError("Logical Entities not supported by this mod (gEntList) - Reverting to networkable entities only");
+		return;
+	}
+	g_EntList = *reinterpret_cast<void **>(addr + offset);
+#elif defined PLATFORM_LINUX
+	/* gEntList and/or g_pEntityList */
+	if (!g_pGameConf->GetMemSig("gEntList", (void **)&addr))
+	{
+		g_Logger.LogError("Logical Entities not supported by this mod (gEntList) - Reverting to networkable entities only");
+		return;
+	}
+	if (!addr)
+	{
+		g_Logger.LogError("Failed lookup of gEntList - Reverting to networkable entities only");
+		return;
+	}
+	g_EntList = reinterpret_cast<void *>(addr);
+#endif
+
+	if (!g_pGameConf->GetOffset("EntInfo", &entInfoOffset))
+	{
+		g_Logger.LogError("Logical Entities not supported by this mod (EntInfo) - Reverting to networkable entities only");
+		return;
+	}
+}
+
 #if !defined METAMOD_PLAPI_VERSION
 bool CHalfLife2::IsOriginalEngine()
 {
@@ -642,3 +691,173 @@ void CHalfLife2::ServerCommand(const char *buffer)
 {
 	engine->ServerCommand(buffer);
 }
+
+cell_t CHalfLife2::EntityToReference(CBaseEntity *pEntity)
+{
+	IServerUnknown *pUnknown = (IServerUnknown *)pEntity;
+	CBaseHandle hndl = pUnknown->GetRefEHandle();
+	return (hndl.ToInt() | (1<<31));
+}
+
+CBaseEntity *CHalfLife2::ReferenceToEntity(cell_t entRef)
+{
+	CEntInfo *pInfo = NULL;
+
+	if (entRef & (1<<31))
+	{
+		/* Proper ent reference */
+		int hndlValue = entRef & ~(1<<31);
+		CBaseHandle hndl(hndlValue);
+
+		pInfo = LookupEntity(hndl.GetEntryIndex());
+		if (pInfo->m_SerialNumber != hndl.GetSerialNumber())
+		{
+			return NULL;
+		}
+	}
+	else
+	{
+		/* Old style index only */
+		pInfo = LookupEntity(entRef);
+	}
+
+	if (!pInfo)
+	{
+		return NULL;
+	}
+
+	IServerUnknown *pUnk = static_cast<IServerUnknown *>(pInfo->m_pEntity);
+	if (pUnk)
+	{
+		return pUnk->GetBaseEntity();
+	}
+
+	return NULL;
+}
+
+/**
+ * Retrieves the CEntInfo pointer from g_EntList for a given entity index
+ */
+CEntInfo *CHalfLife2::LookupEntity(int entIndex)
+{
+	if (!g_EntList || entInfoOffset == -1)
+	{
+		/* Attempt to use engine interface instead */
+		static CEntInfo tempInfo;
+		tempInfo.m_pNext = NULL;
+		tempInfo.m_pPrev = NULL;
+
+		edict_t *pEdict = engine->PEntityOfEntIndex(entIndex);
+
+		if (!pEdict)
+		{
+			return NULL;
+		}
+
+		IServerUnknown *pUnk = pEdict->GetUnknown();
+
+		if (!pUnk)
+		{
+			return NULL;
+		}
+
+		tempInfo.m_pEntity = pUnk;
+		tempInfo.m_SerialNumber = pUnk->GetRefEHandle().GetSerialNumber();
+
+		return &tempInfo;
+	}
+
+	CEntInfo *pArray = (CEntInfo *)(((unsigned char *)g_EntList) + entInfoOffset);
+	return &pArray[entIndex];
+}
+
+/**
+	SERIAL_MASK = 0x7fff (15 bits)
+
+	#define	MAX_EDICT_BITS				11
+	#define NUM_ENT_ENTRY_BITS		(MAX_EDICT_BITS + 1)
+	m_Index = iEntry | (iSerialNumber << NUM_ENT_ENTRY_BITS); 
+	
+	Top 5 bits of a handle are unused.
+	Bit 31 - Our 'reference' flag indicator
+*/
+
+cell_t CHalfLife2::IndexToReference(int entIndex)
+{
+	CBaseEntity *pEnt = ReferenceToEntity(entIndex);
+	if (!pEnt)
+	{
+		return INVALID_EHANDLE_INDEX;
+	}
+
+	return EntityToReference(pEnt);
+}
+
+int CHalfLife2::ReferenceToIndex(cell_t entRef)
+{
+	if (entRef == INVALID_EHANDLE_INDEX)
+	{
+		return INVALID_EHANDLE_INDEX;
+	}
+
+	if (entRef & (1<<31))
+	{
+		/* Proper ent reference */
+		int hndlValue = entRef & ~(1<<31);
+		CBaseHandle hndl(hndlValue);
+
+		CEntInfo *pInfo = LookupEntity(hndl.GetEntryIndex());
+
+		if (pInfo->m_SerialNumber != hndl.GetSerialNumber())
+		{
+			return INVALID_EHANDLE_INDEX;
+		}
+
+		return hndl.GetEntryIndex();
+	}
+
+	return entRef;
+}
+
+cell_t CHalfLife2::EntityToBCompatRef(CBaseEntity *pEntity)
+{
+	if (pEntity == NULL)
+	{
+		return INVALID_EHANDLE_INDEX;
+	}
+
+	IServerUnknown *pUnknown = (IServerUnknown *)pEntity;
+	CBaseHandle hndl = pUnknown->GetRefEHandle();
+
+	if (hndl.GetEntryIndex() >= MAX_EDICTS)
+	{
+		return (hndl.ToInt() | (1<<31));
+	}
+	else
+	{
+		return hndl.GetEntryIndex();
+	}
+}
+
+cell_t CHalfLife2::ReferenceToBCompatRef(cell_t entRef)
+{
+	if (entRef == INVALID_EHANDLE_INDEX)
+	{
+		return INVALID_EHANDLE_INDEX;
+	}
+
+	int hndlValue = entRef & ~(1<<31);
+	CBaseHandle hndl(hndlValue);
+
+	if (hndl.GetEntryIndex() < MAX_EDICTS)
+	{
+		return hndl.GetEntryIndex();
+	}
+
+	return entRef;
+}
+
+void *CHalfLife2::GetGlobalEntityList()
+{
+	return g_EntList;
+}
\ No newline at end of file
diff --git a/core/HalfLife2.h b/core/HalfLife2.h
index b2354661..adf396ee 100644
--- a/core/HalfLife2.h
+++ b/core/HalfLife2.h
@@ -43,6 +43,7 @@
 #include <KeyValues.h>
 #include <server_class.h>
 #include <datamap.h>
+#include <ihandleentity.h>
 
 class CCommand;
 
@@ -86,6 +87,15 @@ struct DelayedKickInfo
 	char buffer[384];
 };
 
+class CEntInfo
+{
+public:
+	IHandleEntity	*m_pEntity;
+	int				m_SerialNumber;
+	CEntInfo		*m_pPrev;
+	CEntInfo		*m_pNext;
+};
+
 class CHalfLife2 : 
 	public SMGlobalClass,
 	public IGameHelpers
@@ -96,6 +106,7 @@ public:
 public:
 	void OnSourceModStartup(bool late);
 	void OnSourceModAllInitialized();
+	void OnSourceModAllInitialized_Post();
 	/*void OnSourceModAllShutdown();*/
 public: //IGameHelpers
 	SendProp *FindInSendTable(const char *classname, const char *offset);
@@ -115,6 +126,14 @@ public: //IGameHelpers
 	void SetHandleEntity(CBaseHandle &hndl, edict_t *pEnt);
 	const char *GetCurrentMap();
 	void ServerCommand(const char *buffer);
+	CBaseEntity *ReferenceToEntity(cell_t entRef);
+	cell_t EntityToReference(CBaseEntity *pEntity);
+	cell_t IndexToReference(int entIndex);
+	int ReferenceToIndex(cell_t entRef);
+	cell_t ReferenceToBCompatRef(cell_t entRef);
+	CEntInfo *LookupEntity(int entIndex);
+	cell_t EntityToBCompatRef(CBaseEntity *pEntity);
+	void *GetGlobalEntityList();
 public:
 	void AddToFakeCliCmdQueue(int client, int userid, const char *cmd);
 	void ProcessFakeCliCmdQueue();
diff --git a/core/smn_banning.cpp b/core/smn_banning.cpp
index b8d8213c..ffd0ede9 100644
--- a/core/smn_banning.cpp
+++ b/core/smn_banning.cpp
@@ -248,7 +248,7 @@ static cell_t BanClient(IPluginContext *pContext, const cell_t *params)
 	char *ban_reason, *ban_cmd;
 	int client, ban_flags, ban_source, ban_time;
 
-	client = params[1];
+	client = g_HL2.ReferenceToIndex(params[1]);
 
 	CPlayer *pPlayer = g_Players.GetPlayerByIndex(client);
 	if (!pPlayer || !pPlayer->IsConnected())
diff --git a/core/smn_bitbuffer.cpp b/core/smn_bitbuffer.cpp
index 11a31229..5ee312b6 100644
--- a/core/smn_bitbuffer.cpp
+++ b/core/smn_bitbuffer.cpp
@@ -33,6 +33,7 @@
 #include "HandleSys.h"
 #include <bitbuf.h>
 #include <vector.h>
+#include <HalfLife2.h>
 
 static cell_t smn_BfWriteBool(IPluginContext *pCtx, const cell_t *params)
 {
@@ -226,7 +227,14 @@ static cell_t smn_BfWriteEntity(IPluginContext *pCtx, const cell_t *params)
 		return pCtx->ThrowNativeError("Invalid bit buffer handle %x (error %d)", hndl, herr);
 	}
 
-	pBitBuf->WriteShort(params[2]);
+	int index = g_HL2.ReferenceToIndex(params[2]);
+
+	if (index == -1)
+	{
+		return 0;
+	}
+
+	pBitBuf->WriteShort(index);
 
 	return 1;
 }
@@ -523,7 +531,9 @@ static cell_t smn_BfReadEntity(IPluginContext *pCtx, const cell_t *params)
 		return pCtx->ThrowNativeError("Invalid bit buffer handle %x (error %d)", hndl, herr);
 	}
 
-	return pBitBuf->ReadShort();
+	int ref = g_HL2.IndexToReference(pBitBuf->ReadShort());
+
+	return g_HL2.ReferenceToBCompatRef(ref);
 }
 
 static cell_t smn_BfReadAngle(IPluginContext *pCtx, const cell_t *params)
diff --git a/core/smn_entities.cpp b/core/smn_entities.cpp
index ab3f2023..0a2d90de 100644
--- a/core/smn_entities.cpp
+++ b/core/smn_entities.cpp
@@ -54,45 +54,74 @@ enum PropFieldType
 	PropField_String_T,			/**< Valid for Data fields.  Read only! */
 };
 
+inline edict_t *BaseEntityToEdict(CBaseEntity *pEntity)
+{
+	IServerUnknown *pUnk = (IServerUnknown *)pEntity;
+	IServerNetworkable *pNet = pUnk->GetNetworkable();
+
+	if (!pNet)
+	{
+		return NULL;
+	}
+
+	return pNet->GetEdict();
+}
+
 inline edict_t *GetEdict(cell_t num)
 {
-	edict_t *pEdict = PEntityOfEntIndex(num);
+	CBaseEntity *pEntity = g_HL2.ReferenceToEntity(num);
+
+	if (!pEntity)
+	{
+		return 0;
+	}
+
+	edict_t *pEdict = ::BaseEntityToEdict(pEntity);
 	if (!pEdict || pEdict->IsFree())
 	{
 		return NULL;
 	}
-	if (num > 0 && num <= g_Players.GetMaxClients())
+
+	int index = g_HL2.ReferenceToIndex(num);
+	if (index > 0 && index <= g_Players.GetMaxClients())
 	{
-		CPlayer *pPlayer = g_Players.GetPlayerByIndex(num);
+		CPlayer *pPlayer = g_Players.GetPlayerByIndex(index);
 		if (!pPlayer || !pPlayer->IsConnected())
 		{
 			return NULL;
 		}
 	}
+
 	return pEdict;
 }
 
 edict_t *GetEntity(cell_t num, CBaseEntity **pData)
 {
-	edict_t *pEdict = PEntityOfEntIndex(num);
-	if (!pEdict || pEdict->IsFree())
+	CBaseEntity *pEntity = g_HL2.ReferenceToEntity(num);
+
+	if (!pEntity)
 	{
-		return NULL;
+		return 0;
 	}
-	if (num > 0 && num <= g_Players.GetMaxClients())
+
+	int index = g_HL2.ReferenceToIndex(num);
+	if (index > 0 && index <= g_Players.GetMaxClients())
 	{
-		CPlayer *pPlayer = g_Players.GetPlayerByIndex(num);
+		CPlayer *pPlayer = g_Players.GetPlayerByIndex(index);
 		if (!pPlayer || !pPlayer->IsConnected())
 		{
 			return NULL;
 		}
 	}
-	IServerUnknown *pUnk;
-	if ((pUnk=pEdict->GetUnknown()) == NULL)
+
+	*pData = pEntity;
+
+	edict_t *pEdict = ::BaseEntityToEdict(pEntity);
+	if (!pEdict || pEdict->IsFree())
 	{
 		return NULL;
 	}
-	*pData = pUnk->GetBaseEntity();
+
 	return pEdict;
 }
 
@@ -161,11 +190,11 @@ static cell_t CreateEdict(IPluginContext *pContext, const cell_t *params)
 
 static cell_t RemoveEdict(IPluginContext *pContext, const cell_t *params)
 {
-	edict_t *pEdict = PEntityOfEntIndex(params[1]);
+	edict_t *pEdict = GetEdict(params[1]);
 
 	if (!pEdict)
 	{
-		return pContext->ThrowNativeError("Edict %d is not a valid edict", params[1]);
+		return pContext->ThrowNativeError("Edict %d (%d) is not a valid edict", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	engine->RemoveEdict(pEdict);
@@ -188,20 +217,8 @@ static cell_t IsValidEdict(IPluginContext *pContext, const cell_t *params)
 
 static cell_t IsValidEntity(IPluginContext *pContext, const cell_t *params)
 {
-	edict_t *pEdict = GetEdict(params[1]);
+	CBaseEntity *pEntity = g_HL2.ReferenceToEntity(params[1]);
 
-	if (!pEdict)
-	{
-		return 0;
-	}
-
-	IServerUnknown *pUnknown = pEdict->GetUnknown();
-	if (!pUnknown)
-	{
-		return 0;
-	}
-
-	CBaseEntity *pEntity = pUnknown->GetBaseEntity();
 	return (pEntity != NULL) ? 1 : 0;
 }
 
@@ -228,7 +245,7 @@ static cell_t GetEdictFlags(IPluginContext *pContext, const cell_t *params)
 
 	if (!pEdict)
 	{
-		return pContext->ThrowNativeError("Invalid edict (%d)", params[1]);
+		return pContext->ThrowNativeError("Invalid edict (%d - %d)", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	return pEdict->m_fStateFlags;
@@ -240,7 +257,7 @@ static cell_t SetEdictFlags(IPluginContext *pContext, const cell_t *params)
 
 	if (!pEdict)
 	{
-		return pContext->ThrowNativeError("Invalid edict (%d)", params[1]);
+		return pContext->ThrowNativeError("Invalid edict (%d - %d)", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	pEdict->m_fStateFlags = params[2];
@@ -254,7 +271,7 @@ static cell_t GetEdictClassname(IPluginContext *pContext, const cell_t *params)
 
 	if (!pEdict)
 	{
-		return pContext->ThrowNativeError("Invalid edict (%d)", params[1]);
+		return pContext->ThrowNativeError("Invalid edict (%d - %d)", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	const char *cls = pEdict->GetClassName();
@@ -271,14 +288,16 @@ static cell_t GetEdictClassname(IPluginContext *pContext, const cell_t *params)
 
 static cell_t GetEntityNetClass(IPluginContext *pContext, const cell_t *params)
 {
-	edict_t *pEdict = GetEdict(params[1]);
+	CBaseEntity *pEntity = g_HL2.ReferenceToEntity(params[1]);
 
-	if (!pEdict)
+	IServerUnknown *pUnk = (IServerUnknown *)pEntity;
+
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Invalid edict (%d)", params[1]);
+		return pContext->ThrowNativeError("Invalid entity (%d - %d)", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	IServerNetworkable *pNet = pEdict->GetNetworkable();
+	IServerNetworkable *pNet = pUnk->GetNetworkable();
 	if (!pNet)
 	{
 		return 0;
@@ -294,11 +313,11 @@ static cell_t GetEntityNetClass(IPluginContext *pContext, const cell_t *params)
 static cell_t GetEntData(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -325,9 +344,9 @@ static cell_t SetEntData(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -336,7 +355,7 @@ static cell_t SetEntData(IPluginContext *pContext, const cell_t *params)
 		return pContext->ThrowNativeError("Offset %d is invalid", offset);
 	}
 
-	if (params[5])
+	if (params[5] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -368,11 +387,11 @@ static cell_t SetEntData(IPluginContext *pContext, const cell_t *params)
 static cell_t GetEntDataFloat(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -391,9 +410,9 @@ static cell_t SetEntDataFloat(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -404,7 +423,7 @@ static cell_t SetEntDataFloat(IPluginContext *pContext, const cell_t *params)
 
 	*(float *)((uint8_t *)pEntity + offset) = sp_ctof(params[3]);
 
-	if (params[4])
+	if (params[4] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -415,11 +434,11 @@ static cell_t SetEntDataFloat(IPluginContext *pContext, const cell_t *params)
 static cell_t GetEntDataVector(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -445,9 +464,9 @@ static cell_t SetEntDataVector(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -465,7 +484,7 @@ static cell_t SetEntDataVector(IPluginContext *pContext, const cell_t *params)
 	v->y = sp_ctof(vec[1]);
 	v->z = sp_ctof(vec[2]);
 
-	if (params[4])
+	if (params[4] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -477,11 +496,11 @@ static cell_t SetEntDataVector(IPluginContext *pContext, const cell_t *params)
 static cell_t GetEntDataEnt(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -497,7 +516,8 @@ static cell_t GetEntDataEnt(IPluginContext *pContext, const cell_t *params)
 		return 0;
 	}
 
-	return hndl.GetEntryIndex();
+	int ref = g_HL2.IndexToReference(hndl.GetEntryIndex());
+	return g_HL2.ReferenceToBCompatRef(ref);
 }
 
 int CheckBaseHandle(CBaseHandle &hndl)
@@ -537,11 +557,11 @@ int CheckBaseHandle(CBaseHandle &hndl)
 static cell_t GetEntDataEnt2(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (pEdict == NULL || pEntity == NULL)
+	if (pEntity == NULL)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -552,7 +572,8 @@ static cell_t GetEntDataEnt2(IPluginContext *pContext, const cell_t *params)
 
 	CBaseHandle &hndl = *(CBaseHandle *)((uint8_t *)pEntity + offset);
 
-	return CheckBaseHandle(hndl);
+	int ref = g_HL2.IndexToReference(hndl.GetEntryIndex());
+	return g_HL2.ReferenceToBCompatRef(ref);
 }
 
 /* THIS GUY IS DEPRECATED. */
@@ -561,9 +582,9 @@ static cell_t SetEntDataEnt(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -574,20 +595,23 @@ static cell_t SetEntDataEnt(IPluginContext *pContext, const cell_t *params)
 
 	CBaseHandle &hndl = *(CBaseHandle *)((uint8_t *)pEntity + offset);
 
-	if (params[3] == 0)
+	if (params[3] == 0 || params[3] == INVALID_EHANDLE_INDEX)
 	{
 		hndl.Set(NULL);
 	} else {
-		edict_t *pEdict = GetEdict(params[3]);
-		if (!pEdict)
+		CBaseEntity *pOther;
+		GetEntity(params[3], &pOther);
+
+		if (!pOther)
 		{
-			return pContext->ThrowNativeError("Entity %d is invalid", params[3]);
+			return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[3]), params[3]);
 		}
-		IServerEntity *pEntOther = pEdict->GetIServerEntity();
-		hndl.Set(pEntOther);
+
+		IHandleEntity *pHandleEnt = (IHandleEntity *)pOther;
+		hndl.Set(pHandleEnt);
 	}
 
-	if (params[4])
+	if (params[4] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -600,9 +624,9 @@ static cell_t SetEntDataEnt2(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -613,22 +637,25 @@ static cell_t SetEntDataEnt2(IPluginContext *pContext, const cell_t *params)
 
 	CBaseHandle &hndl = *(CBaseHandle *)((uint8_t *)pEntity + offset);
 
-	if (params[3] == -1)
+	if (params[3] == INVALID_EHANDLE_INDEX)
 	{
 		hndl.Set(NULL);
 	}
 	else
 	{
-		edict_t *pEdict = GetEdict(params[3]);
-		if (!pEdict)
+		CBaseEntity *pOther;
+		GetEntity(params[3], &pOther);
+
+		if (!pOther)
 		{
-			return pContext->ThrowNativeError("Entity %d is invalid", params[3]);
+			return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[3]), params[3]);
 		}
-		IServerEntity *pEntOther = pEdict->GetIServerEntity();
-		hndl.Set(pEntOther);
+
+		IHandleEntity *pHandleEnt = (IHandleEntity *)pOther;
+		hndl.Set(pHandleEnt);
 	}
 
-	if (params[4])
+	if (params[4] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -642,7 +669,7 @@ static cell_t ChangeEdictState(IPluginContext *pContext, const cell_t *params)
 
 	if (!pEdict)
 	{
-		return pContext->ThrowNativeError("Edict %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Edict %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	g_HL2.SetEdictStateChanged(pEdict, params[2]);
@@ -725,11 +752,11 @@ static cell_t FindDataMapOffs(IPluginContext *pContext, const cell_t *params)
 	datamap_t *pMap;
 	typedescription_t *td;
 	char *offset;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	if ((pMap=CBaseEntity_GetDataDescMap(pEntity)) == NULL)
@@ -830,11 +857,11 @@ static cell_t FindDataMapOffs(IPluginContext *pContext, const cell_t *params)
 static cell_t GetEntDataString(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict = GetEntity(params[1], &pEntity);
+	GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -855,9 +882,9 @@ static cell_t SetEntDataString(IPluginContext *pContext, const cell_t *params)
 	CBaseEntity *pEntity;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	int offset = params[2];
@@ -872,7 +899,7 @@ static cell_t SetEntDataString(IPluginContext *pContext, const cell_t *params)
 	pContext->LocalToString(params[3], &src);
 	size_t len = strncopy(dest, src, params[4]);
 
-	if (params[5])
+	if (params[5] && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -895,10 +922,11 @@ static cell_t SetEntDataString(IPluginContext *pContext, const cell_t *params)
 	}
 
 #define FIND_PROP_SEND(pProp) \
-	IServerNetworkable *pNet = pEdict->GetNetworkable(); \
+	IServerUnknown *pUnk = (IServerUnknown *)pEntity; \
+	IServerNetworkable *pNet = pUnk->GetNetworkable(); \
 	if (!pNet) \
 	{ \
-		return pContext->ThrowNativeError("Edict %d is not networkable", params[1]); \
+		return pContext->ThrowNativeError("Edict %d (%d) is not networkable", g_HL2.ReferenceToIndex(params[1]), params[1]); \
 	} \
 	if (!g_HL2.FindSendPropInfo(pNet->GetServerClass()->GetName(), prop, pProp)) \
 	{ \
@@ -942,12 +970,13 @@ static cell_t GetEntProp(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	/* TODO: Find a way to lookup classname without having an edict - Is this a guaranteed prop? */
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1033,12 +1062,12 @@ static cell_t SetEntProp(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1123,12 +1152,12 @@ static cell_t GetEntPropFloat(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1194,12 +1223,12 @@ static cell_t SetEntPropFloat(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1252,7 +1281,7 @@ static cell_t SetEntPropFloat(IPluginContext *pContext, const cell_t *params)
 
 	*(float *)((uint8_t *)pEntity + offset) = sp_ctof(params[4]);
 
-	if (params[2] == Prop_Send)
+	if (params[2] == Prop_Send && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -1270,12 +1299,12 @@ static cell_t GetEntPropEnt(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1326,7 +1355,8 @@ static cell_t GetEntPropEnt(IPluginContext *pContext, const cell_t *params)
 
 	CBaseHandle &hndl = *(CBaseHandle *)((uint8_t *)pEntity + offset);
 
-	return CheckBaseHandle(hndl);
+	int ref = g_HL2.IndexToReference(hndl.GetEntryIndex());
+	return g_HL2.ReferenceToBCompatRef(ref);
 }
 
 static cell_t SetEntPropEnt(IPluginContext *pContext, const cell_t *params)
@@ -1339,12 +1369,12 @@ static cell_t SetEntPropEnt(IPluginContext *pContext, const cell_t *params)
 
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1401,18 +1431,19 @@ static cell_t SetEntPropEnt(IPluginContext *pContext, const cell_t *params)
 	}
 	else
 	{
-		edict_t *pOther;
-		CBaseEntity *pOtherEnt;
+		CBaseEntity *pOther;
+		GetEntity(params[4], &pOther);
 
-		if ((pOther = GetEntity(params[4], &pOtherEnt)) == NULL)
+		if (!pOther)
 		{
-			return pContext->ThrowNativeError("Invalid entity %d", params[4]);
+			return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[4]), params[4]);
 		}
 
-		hndl.Set(pOther->GetIServerEntity());
+		IHandleEntity *pHandleEnt = (IHandleEntity *)pOther;
+		hndl.Set(pHandleEnt);
 	}
 
-	if (params[2] == Prop_Send)
+	if (params[2] == Prop_Send && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -1430,12 +1461,12 @@ static cell_t GetEntPropVector(IPluginContext *pContext, const cell_t *params)
 	
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1508,12 +1539,12 @@ static cell_t SetEntPropVector(IPluginContext *pContext, const cell_t *params)
 	
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1573,7 +1604,7 @@ static cell_t SetEntPropVector(IPluginContext *pContext, const cell_t *params)
 	v->y = sp_ctof(vec[1]);
 	v->z = sp_ctof(vec[2]);
 
-	if (params[2] == Prop_Send)
+	if (params[2] == Prop_Send && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
@@ -1592,12 +1623,12 @@ static cell_t GetEntPropString(IPluginContext *pContext, const cell_t *params)
 	
 	pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
-	if ((class_name = pEdict->GetClassName()) == NULL)
+	if (!pEdict || (class_name = pEdict->GetClassName()) == NULL)
 	{
 		class_name = "";
 	}
@@ -1682,9 +1713,9 @@ static cell_t SetEntPropString(IPluginContext *pContext, const cell_t *params)
 	int maxlen;
 	edict_t *pEdict = GetEntity(params[1], &pEntity);
 
-	if (!pEdict || !pEntity)
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
+		return pContext->ThrowNativeError("Entity %d (%d) is invalid", g_HL2.ReferenceToIndex(params[1]), params[1]);
 	}
 
 	switch (params[2])
@@ -1713,7 +1744,8 @@ static cell_t SetEntPropString(IPluginContext *pContext, const cell_t *params)
 	case Prop_Send:
 		{
 			char *prop;
-			IServerNetworkable *pNet = pEdict->GetNetworkable();
+			IServerUnknown *pUnk = (IServerUnknown *)pEntity;
+			IServerNetworkable *pNet = pUnk->GetNetworkable();
 			if (!pNet)
 			{
 				return pContext->ThrowNativeError("The edict is not networkable");
@@ -1744,7 +1776,7 @@ static cell_t SetEntPropString(IPluginContext *pContext, const cell_t *params)
 	pContext->LocalToString(params[4], &src);
 	size_t len = strncopy(dest, src, maxlen);
 
-	if (params[2] == Prop_Send)
+	if (params[2] == Prop_Send && (pEdict != NULL))
 	{
 		g_HL2.SetEdictStateChanged(pEdict, offset);
 	}
diff --git a/core/smn_halflife.cpp b/core/smn_halflife.cpp
index 155c254f..0e98237d 100644
--- a/core/smn_halflife.cpp
+++ b/core/smn_halflife.cpp
@@ -475,6 +475,26 @@ static cell_t GuessSDKVersion(IPluginContext *pContext, const cell_t *params)
 	return 0;
 }
 
+static cell_t IndexToReference(IPluginContext *pContext, const cell_t *params)
+{
+	if (params[1] >= NUM_ENT_ENTRIES || params[1] < 0)
+	{
+		return pContext->ThrowNativeError("Invalid entity index %i", params[1]);
+	}
+
+	return g_HL2.IndexToReference(params[1]);
+}
+
+static cell_t ReferenceToIndex(IPluginContext *pContext, const cell_t *params)
+{
+	return g_HL2.ReferenceToIndex(params[1]);
+}
+
+static cell_t ReferenceToBCompatRef(IPluginContext *pContext, const cell_t *params)
+{
+	return g_HL2.ReferenceToBCompatRef(params[1]);
+}
+
 REGISTER_NATIVES(halflifeNatives)
 {
 	{"CreateFakeClient",		CreateFakeClient},
@@ -505,5 +525,8 @@ REGISTER_NATIVES(halflifeNatives)
 	{"ShowVGUIPanel",			ShowVGUIPanel},
 	{"IsPlayerAlive",			smn_IsPlayerAlive},
 	{"GuessSDKVersion",			GuessSDKVersion},
+	{"EntIndexToEntRef",		IndexToReference},
+	{"EntRefToEntIndex",		ReferenceToIndex},
+	{"MakeCompatEntRef",		ReferenceToBCompatRef},
 	{NULL,						NULL},
 };
diff --git a/extensions/sdktools/inputnatives.cpp b/extensions/sdktools/inputnatives.cpp
index b0bcbf44..03090bb5 100644
--- a/extensions/sdktools/inputnatives.cpp
+++ b/extensions/sdktools/inputnatives.cpp
@@ -37,21 +37,11 @@
 ICallWrapper *g_pAcceptInput = NULL;
 unsigned char g_Variant_t[SIZEOF_VARIANT_T] = {0};
 
-#define ENTINDEX_TO_CBASEENTITY(index, buffer) \
-	pEdict = PEntityOfEntIndex(index); \
-	if (!pEdict || pEdict->IsFree()) \
-	{ \
-		return pContext->ThrowNativeError("Entity %d is not valid or is freed", index); \
-	} \
-	pUnk = pEdict->GetUnknown(); \
-	if (!pUnk) \
-	{ \
-		return pContext->ThrowNativeError("Entity %d is a not an IServerUnknown", index); \
-	} \
-	buffer = pUnk->GetBaseEntity(); \
+#define ENTINDEX_TO_CBASEENTITY(ref, buffer) \
+	buffer = gamehelpers->ReferenceToEntity(ref); \
 	if (!buffer) \
 	{ \
-		return pContext->ThrowNativeError("Entity %d is not a CBaseEntity", index); \
+		return pContext->ThrowNativeError("Entity %d (%d) is not a CBaseEntity", gamehelpers->ReferenceToIndex(ref), ref); \
 	}
 
 /* Hack to init the variant_t object for the first time */
@@ -109,8 +99,6 @@ static cell_t AcceptEntityInput(IPluginContext *pContext, const cell_t *params)
 	}
 
 	CBaseEntity *pActivator, *pCaller, *pDest;
-	edict_t *pEdict;
-	IServerUnknown *pUnk;
 
 	char *inputname;
 	unsigned char vstk[sizeof(void *) + sizeof(const char *) + sizeof(CBaseEntity *)*2 + SIZEOF_VARIANT_T + sizeof(int)];
@@ -257,8 +245,6 @@ static cell_t SetVariantColor(IPluginContext *pContext, const cell_t *params)
 static cell_t SetVariantEntity(IPluginContext *pContext, const cell_t *params)
 {
 	CBaseEntity *pEntity;
-	edict_t *pEdict;
-	IServerUnknown *pUnk;
 	unsigned char *vptr = g_Variant_t;
 	CBaseHandle bHandle;
 
diff --git a/extensions/sdktools/output.cpp b/extensions/sdktools/output.cpp
index a77163ae..97a6786d 100644
--- a/extensions/sdktools/output.cpp
+++ b/extensions/sdktools/output.cpp
@@ -205,20 +205,12 @@ void EntityOutputManager::FireEventDetour(void *pOutput, CBaseEntity *pActivator
 	// attempt to directly lookup a hook using the pOutput pointer
 	OutputNameStruct *pOutputName = NULL;
 
-	edict_t *pEdict = gameents->BaseEntityToEdict(pCaller);
-
-	/* TODO: Add support for entities without an edict */
-	if (pEdict == NULL)
-	{
-		return;
-	}
-
 	bool fastLookup = false;
 	
 	// Fast lookup failed - check the slow way for hooks that havn't fired yet
 	if ((fastLookup = EntityOutputs->Retrieve(sOutput, (void **)&pOutputName)) == false)
 	{
-		const char *classname = pEdict->GetClassName();
+		const char *classname = GetEntityClassname(pCaller);
 		const char *outputname = FindOutputName(pOutput, pCaller);
 
 		pOutputName = FindOutputPointer(classname, outputname, false);
@@ -249,37 +241,31 @@ void EntityOutputManager::FireEventDetour(void *pOutput, CBaseEntity *pActivator
 
 			hook->in_use = true;
 
-			int serial = pEdict->m_NetworkSerialNumber;
+			cell_t ref = gamehelpers->EntityToReference(pCaller);
 			
-			if (serial != hook->entity_filter && hook->entity_index == IndexOfEdict(pEdict))
+			if (hook->entity_ref != -1 
+					&& gamehelpers->ReferenceToIndex(hook->entity_ref) == gamehelpers->ReferenceToIndex(ref)
+					&& ref != hook->entity_ref)
 			{
-				// same entity index but different serial number. Entity has changed, kill the hook.
+				// same entity index but different reference. Entity has changed, kill the hook.
 				_iter = pOutputName->hooks.erase(_iter);
 				CleanUpHook(hook);
 
 				continue;
 			}
 
-			if (hook->entity_filter == -1 || hook->entity_filter == serial) // Global classname hook
+			if (hook->entity_ref == -1 || hook->entity_ref == ref) // Global classname hook
 			{
 				//fire the forward to hook->pf
 				hook->pf->PushString(pOutputName->Name);
-				hook->pf->PushCell(IndexOfEdict(pEdict));
-				
-				edict_t *pEdictActivator = gameents->BaseEntityToEdict(pActivator);
-				if (!pEdictActivator)
-				{
-					hook->pf->PushCell(-1);
-				}
-				else
-				{
-					hook->pf->PushCell(IndexOfEdict(pEdictActivator));
-				}
+				hook->pf->PushCell(gamehelpers->ReferenceToBCompatRef(ref));
+				hook->pf->PushCell(gamehelpers->EntityToBCompatRef(pActivator));
+
 				//hook->pf->PushCell(handle);
 				hook->pf->PushFloat(fDelay);
 				hook->pf->Execute(NULL);
 
-				if ((hook->entity_filter != -1) && hook->only_once)
+				if ((hook->entity_ref != -1) && hook->only_once)
 				{
 					_iter = pOutputName->hooks.erase(_iter);
 					CleanUpHook(hook);
@@ -454,36 +440,15 @@ const char *EntityOutputManager::FindOutputName(void *pOutput, CBaseEntity *pCal
 	return NULL;
 }
 
-// Thanks SM core
-edict_t *EntityOutputManager::BaseHandleToEdict(CBaseHandle &hndl)
+const char *EntityOutputManager::GetEntityClassname(CBaseEntity *pEntity)
 {
-	if (!hndl.IsValid())
+	static int offset = -1;
+	if (offset == -1)
 	{
-		return NULL;
+		datamap_t *pMap = gamehelpers->GetDataMap(pEntity);
+		typedescription_t *pDesc = gamehelpers->FindInDataMap(pMap, "m_iClassname");
+		offset = pDesc->fieldOffset[TD_OFFSET_NORMAL];
 	}
 
-	int index = hndl.GetEntryIndex();
-
-	edict_t *pStoredEdict;
-
-	pStoredEdict = PEntityOfEntIndex(index);
-
-	if (pStoredEdict == NULL)
-	{
-		return NULL;
-	}
-
-	IServerEntity *pSE = pStoredEdict->GetIServerEntity();
-
-	if (pSE == NULL)
-	{
-		return NULL;
-	}
-
-	if (pSE->GetRefEHandle() != hndl)
-	{
-		return NULL;
-	}
-
-	return pStoredEdict;
-}
+	return (const char *)(((unsigned char *)pEntity) + offset);
+}
\ No newline at end of file
diff --git a/extensions/sdktools/output.h b/extensions/sdktools/output.h
index c696feeb..afaf40d9 100644
--- a/extensions/sdktools/output.h
+++ b/extensions/sdktools/output.h
@@ -49,8 +49,7 @@ struct OutputNameStruct;
  */
 struct omg_hooks 
 {
-	int entity_filter; // if not -1 is an entity signature
-	int entity_index;
+	cell_t entity_ref;
 	bool only_once;
 	IPluginFunction *pf;
 	OutputNameStruct *m_parent;
@@ -110,6 +109,8 @@ public:
 	void OnHookAdded();
 	void OnHookRemoved();
 
+	const char *GetEntityClassname(CBaseEntity *pEntity);
+
 private:
 	bool enabled;
 
@@ -123,7 +124,6 @@ private:
 	void DeleteFireEventDetour();
 
 	const char *FindOutputName(void *pOutput, CBaseEntity *pCaller);
-	edict_t *BaseHandleToEdict(CBaseHandle &hndl);
 
 	//Maps CEntityOutput * to a OutputNameStruct
 	IBasicTrie *EntityOutputs;
diff --git a/extensions/sdktools/outputnatives.cpp b/extensions/sdktools/outputnatives.cpp
index dc33cd50..4c14683b 100644
--- a/extensions/sdktools/outputnatives.cpp
+++ b/extensions/sdktools/outputnatives.cpp
@@ -40,12 +40,13 @@ cell_t HookSingleEntityOutput(IPluginContext *pContext, const cell_t *params)
 		return pContext->ThrowNativeError("Entity Outputs are disabled - See error logs for details");
 	}
 
-	edict_t *pEdict = PEntityOfEntIndex(params[1]);
-	if (!pEdict)
+	CBaseEntity *pEntity = gamehelpers->ReferenceToEntity(params[1]);
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Invalid Entity index %i", params[1]);
+		return pContext->ThrowNativeError("Invalid Entity index %i (%i)", gamehelpers->ReferenceToIndex(params[1]), params[1]);
 	}
-	const char *classname = pEdict->GetClassName();
+
+	const char *classname = g_OutputManager.GetEntityClassname(pEntity);
 
 	char *outputname;
 	pContext->LocalToString(params[2], &outputname);
@@ -63,7 +64,7 @@ cell_t HookSingleEntityOutput(IPluginContext *pContext, const cell_t *params)
 	for (_iter=pOutputName->hooks.begin(); _iter!=pOutputName->hooks.end(); _iter++)
 	{
 		hook = (omg_hooks *)*_iter;
-		if (hook->pf == pFunction && hook->entity_filter == pEdict->m_NetworkSerialNumber)
+		if (hook->pf == pFunction && hook->entity_ref == gamehelpers->EntityToReference(pEntity))
 		{
 			return 0;
 		}
@@ -71,8 +72,7 @@ cell_t HookSingleEntityOutput(IPluginContext *pContext, const cell_t *params)
 
 	hook = g_OutputManager.NewHook();
 
-	hook->entity_filter = pEdict->m_NetworkSerialNumber;
-	hook->entity_index = IndexOfEdict(pEdict);
+	hook->entity_ref = gamehelpers->EntityToReference(pEntity);
 	hook->only_once= !!params[4];
 	hook->pf = pFunction;
 	hook->m_parent = pOutputName;
@@ -125,7 +125,7 @@ cell_t HookEntityOutput(IPluginContext *pContext, const cell_t *params)
 	for (_iter=pOutputName->hooks.begin(); _iter!=pOutputName->hooks.end(); _iter++)
 	{
 		hook = (omg_hooks *)*_iter;
-		if (hook->pf == pFunction && hook->entity_filter == -1)
+		if (hook->pf == pFunction && hook->entity_ref == -1)
 		{
 			//already hooked to this function...
 			//throw an error or just let them get away with stupidity?
@@ -136,7 +136,7 @@ cell_t HookEntityOutput(IPluginContext *pContext, const cell_t *params)
 
 	hook = g_OutputManager.NewHook();
 
-	hook->entity_filter = -1;
+	hook->entity_ref = -1;
 	hook->pf = pFunction;
 	hook->m_parent = pOutputName;
 	hook->in_use = false;
@@ -192,7 +192,7 @@ cell_t UnHookEntityOutput(IPluginContext *pContext, const cell_t *params)
 	for (_iter=pOutputName->hooks.begin(); _iter!=pOutputName->hooks.end(); _iter++)
 	{
 		hook = (omg_hooks *)*_iter;
-		if (hook->pf == pFunction && hook->entity_filter == -1)
+		if (hook->pf == pFunction && hook->entity_ref == -1)
 		{
 			// remove this hook.
 			if (hook->in_use)
@@ -220,13 +220,13 @@ cell_t UnHookSingleEntityOutput(IPluginContext *pContext, const cell_t *params)
 	}
 
 	// Find the classname of the entity and lookup the classname and output structures
-	edict_t *pEdict = PEntityOfEntIndex(params[1]);
-	if (!pEdict)
+	CBaseEntity *pEntity = gamehelpers->ReferenceToEntity(params[1]);
+	if (!pEntity)
 	{
-		return pContext->ThrowNativeError("Invalid Entity index %i", params[1]);
+		return pContext->ThrowNativeError("Invalid Entity index %i (%i)", gamehelpers->ReferenceToIndex(params[1]), params[1]);
 	}
 
-	const char *classname = pEdict->GetClassName();
+	const char *classname = g_OutputManager.GetEntityClassname(pEntity);
 
 	char *outputname;
 	pContext->LocalToString(params[2], &outputname);
@@ -249,7 +249,8 @@ cell_t UnHookSingleEntityOutput(IPluginContext *pContext, const cell_t *params)
 	for (_iter=pOutputName->hooks.begin(); _iter!=pOutputName->hooks.end(); _iter++)
 	{
 		hook = (omg_hooks *)*_iter;
-		if (hook->pf == pFunction && hook->entity_index == IndexOfEdict(pEdict))
+		/* We're not serial checking and just removing by index here - This was always allowed so is left for bcompat */
+		if (hook->pf == pFunction && gamehelpers->ReferenceToIndex(hook->entity_ref) == gamehelpers->ReferenceToIndex(params[1]))
 		{
 			// remove this hook.
 			if (hook->in_use)
diff --git a/extensions/sdktools/trnatives.cpp b/extensions/sdktools/trnatives.cpp
index 3bf555de..6503921a 100644
--- a/extensions/sdktools/trnatives.cpp
+++ b/extensions/sdktools/trnatives.cpp
@@ -38,8 +38,7 @@ public:
 	bool ShouldHitEntity(IHandleEntity *pEntity, int contentsMask)
 	{
 		cell_t res = 1;
-		edict_t *pEdict = gameents->BaseEntityToEdict(reinterpret_cast<CBaseEntity *>(pEntity));
-		m_pFunc->PushCell(IndexOfEdict(pEdict));
+		m_pFunc->PushCell(gamehelpers->EntityToBCompatRef(reinterpret_cast<CBaseEntity *>(pEntity)));
 		m_pFunc->PushCell(contentsMask);
 		m_pFunc->PushCell(m_Data);
 		m_pFunc->Execute(&res);
@@ -505,8 +504,7 @@ static cell_t smn_TRGetEntityIndex(IPluginContext *pContext, const cell_t *param
 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", params[1], err);
 	}
 
-	edict_t *pEdict = gameents->BaseEntityToEdict(tr->m_pEnt);
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(tr->m_pEnt);
 }
 
 static cell_t smn_TRGetPointContents(IPluginContext *pContext, const cell_t *params)
@@ -532,8 +530,7 @@ static cell_t smn_TRGetPointContents(IPluginContext *pContext, const cell_t *par
 #else
 		mask = enginetrace->GetPointContents(pos, &hentity);
 #endif
-		edict_t *pEdict = gameents->BaseEntityToEdict(reinterpret_cast<CBaseEntity *>(hentity));
-		*ent = IndexOfEdict(pEdict);
+		*ent = gamehelpers->EntityToBCompatRef(reinterpret_cast<CBaseEntity *>(hentity));
 	}
 
 	return mask;
@@ -541,7 +538,8 @@ static cell_t smn_TRGetPointContents(IPluginContext *pContext, const cell_t *par
 
 static cell_t smn_TRGetPointContentsEnt(IPluginContext *pContext, const cell_t *params)
 {
-	edict_t *pEdict = PEntityOfEntIndex(params[1]);
+	/* TODO: See if we can get the collidable with a prop and remove the reliance on edicts */
+	edict_t *pEdict = PEntityOfEntIndex(gamehelpers->ReferenceToIndex(params[1]));
 	if (!pEdict || pEdict->IsFree())
 	{
 		return pContext->ThrowNativeError("Entity %d is invalid", params[1]);
diff --git a/extensions/sdktools/vdecoder.cpp b/extensions/sdktools/vdecoder.cpp
index 1e6e2131..9c08a244 100644
--- a/extensions/sdktools/vdecoder.cpp
+++ b/extensions/sdktools/vdecoder.cpp
@@ -222,8 +222,7 @@ DataStatus EncodeValveParam(IPluginContext *pContext,
 			CBaseEntity *pEntity = *(CBaseEntity **)buffer;
 			if (pEntity)
 			{
-				edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-				*addr = IndexOfEdict(pEdict);
+				*addr = gamehelpers->EntityToBCompatRef(pEntity);
 			} else {
 				*addr = -1;
 			}
@@ -384,16 +383,21 @@ DataStatus DecodeValveParam(IPluginContext *pContext,
 		}
 	case Valve_CBasePlayer:
 		{
-			edict_t *pEdict;
+			CBaseEntity *pEntity = NULL;
 			if (data->decflags & VDECODE_FLAG_BYREF)
 			{
 				cell_t *addr;
 				pContext->LocalToPhysAddr(param, &addr);
 				param = *addr;
 			}
-			if (param >= 1 && param <= playerhelpers->GetMaxClients())
+			int index = gamehelpers->ReferenceToIndex(param);
+			if (index == INVALID_EHANDLE_INDEX && param != -1)
 			{
-				IGamePlayer *player = playerhelpers->GetGamePlayer(param);
+				return Data_Fail;
+			}
+			if (index >= 1 && index <= playerhelpers->GetMaxClients())
+			{
+				IGamePlayer *player = playerhelpers->GetGamePlayer(index);
 				if ((data->decflags & VDECODE_FLAG_ALLOWNOTINGAME)
 					&& !player->IsConnected())
 				{
@@ -403,44 +407,20 @@ DataStatus DecodeValveParam(IPluginContext *pContext,
 					pContext->ThrowNativeError("Client %d is not in game", param);
 					return Data_Fail;
 				}
-				pEdict = player->GetEdict();
+				pEntity = gamehelpers->ReferenceToEntity(param);
 			} else if (param == -1) {
 				if (data->decflags & VDECODE_FLAG_ALLOWNULL)
 				{
-					pEdict = NULL;
+					pEntity = NULL;
 				} else {
 					pContext->ThrowNativeError("NULL not allowed");
 					return Data_Fail;
 				}
-			} else if (param == 0) {
-				if (data->decflags & VDECODE_FLAG_ALLOWWORLD)
-				{
-					pEdict = PEntityOfEntIndex(0);
-				} else {
-					pContext->ThrowNativeError("World not allowed");
-					return Data_Fail;
-				}
 			} else {
 				pContext->ThrowNativeError("Entity index %d is not a valid client", param);
 				return Data_Fail;
 			}
-			CBaseEntity *pEntity = NULL;
-			if (pEdict)
-			{
-				IServerUnknown *pUnknown = pEdict->GetUnknown();
-				if (!pUnknown)
-				{
-					pContext->ThrowNativeError("Entity %d is a not an IServerUnknown", param);
-					return Data_Fail;
-				}
-				pEntity = pUnknown->GetBaseEntity();
-				if (!pEntity)
-				{
-					pContext->ThrowNativeError("Entity %d is not a CBaseEntity", param);
-					return Data_Fail;
-				}
-			}
-
+			
 			CBaseEntity **ebuf = (CBaseEntity **)buffer;
 			*ebuf = pEntity;
 
@@ -448,16 +428,21 @@ DataStatus DecodeValveParam(IPluginContext *pContext,
 		}
 	case Valve_CBaseEntity:
 		{
-			edict_t *pEdict;
+			CBaseEntity *pEntity = NULL;
 			if (data->decflags & VDECODE_FLAG_BYREF)
 			{
 				cell_t *addr;
 				pContext->LocalToPhysAddr(param, &addr);
 				param = *addr;
 			}
-			if (param >= 1 && param <= playerhelpers->GetMaxClients())
+			int index = gamehelpers->ReferenceToIndex(param);
+			if (index == INVALID_EHANDLE_INDEX && param != -1)
 			{
-				IGamePlayer *player = playerhelpers->GetGamePlayer(param);
+				return Data_Fail;
+			}
+			if (index >= 1 && index <= playerhelpers->GetMaxClients())
+			{
+				IGamePlayer *player = playerhelpers->GetGamePlayer(index);
 				if ((data->decflags & VDECODE_FLAG_ALLOWNOTINGAME)
 					&& !player->IsConnected())
 				{
@@ -467,44 +452,28 @@ DataStatus DecodeValveParam(IPluginContext *pContext,
 					pContext->ThrowNativeError("Client %d is not in game", param);
 					return Data_Fail;
 				}
-				pEdict = player->GetEdict();
+				pEntity = gamehelpers->ReferenceToEntity(param);
 			} else if (param == -1) {
 				if (data->decflags & VDECODE_FLAG_ALLOWNULL)
 				{
-					pEdict = NULL;
+					pEntity = NULL;
 				} else {
 					pContext->ThrowNativeError("NULL not allowed");
 					return Data_Fail;
 				}
-			} else if (param == 0) {
+			} else if (index == 0) {
 				if (data->decflags & VDECODE_FLAG_ALLOWWORLD)
 				{
-					pEdict = PEntityOfEntIndex(0);
+					pEntity = gamehelpers->ReferenceToEntity(0);
 				} else {
 					pContext->ThrowNativeError("World not allowed");
 					return Data_Fail;
 				}
 			} else {
-				pEdict = PEntityOfEntIndex(param);
-				if (!pEdict || pEdict->IsFree())
-				{
-					pContext->ThrowNativeError("Entity %d is not valid or is freed", param);
-					return Data_Fail;
-				}
-			}
-			CBaseEntity *pEntity = NULL;
-			if (pEdict)
-			{
-				IServerUnknown *pUnknown = pEdict->GetUnknown();
-				if (!pUnknown)
-				{
-					pContext->ThrowNativeError("Entity %d is a not an IServerUnknown", param);
-					return Data_Fail;
-				}
-				pEntity = pUnknown->GetBaseEntity();
+				pEntity = gamehelpers->ReferenceToEntity(param);
 				if (!pEntity)
 				{
-					pContext->ThrowNativeError("Entity %d is not a CBaseEntity", param);
+					pContext->ThrowNativeError("Entity %d is not valid", param);
 					return Data_Fail;
 				}
 			}
diff --git a/extensions/sdktools/vglobals.cpp b/extensions/sdktools/vglobals.cpp
index 1102538b..681d21cf 100644
--- a/extensions/sdktools/vglobals.cpp
+++ b/extensions/sdktools/vglobals.cpp
@@ -34,54 +34,35 @@
 void **g_pGameRules = NULL;
 void *g_EntList = NULL;
 
-#ifdef PLATFORM_WINDOWS
+
 void InitializeValveGlobals()
 {
-	char *addr = NULL;
-	int offset;
+	g_EntList = gamehelpers->GetGlobalEntityList();
 
-	/* gEntList and/or g_pEntityList */
-	if (!g_pGameConf->GetMemSig("LevelShutdown", (void **)&addr) || !addr)
-	{
-		return;
-	}
-	if (!g_pGameConf->GetOffset("gEntList", &offset) || !offset)
-	{
-		return;
-	}
-	g_EntList = *reinterpret_cast<void **>(addr + offset);
+	char *addr;
 
+#ifdef PLATFORM_WINDOWS
 	/* g_pGameRules */
 	if (!g_pGameConf->GetMemSig("CreateGameRulesObject", (void **)&addr) || !addr)
 	{
 		return;
 	}
+
+	int offset;
 	if (!g_pGameConf->GetOffset("g_pGameRules", &offset) || !offset)
 	{
 		return;
 	}
 	g_pGameRules = *reinterpret_cast<void ***>(addr + offset);
-}
 #elif defined PLATFORM_LINUX
-void InitializeValveGlobals()
-{
-	char *addr = NULL;
-
-	/* gEntList and/or g_pEntityList */
-	if (!g_pGameConf->GetMemSig("gEntList", (void **)&addr) || !addr)
-	{
-		return;
-	}
-	g_EntList = reinterpret_cast<void *>(addr);
-
 	/* g_pGameRules */
 	if (!g_pGameConf->GetMemSig("g_pGameRules", (void **)&addr) || !addr)
 	{
 		return;
 	}
 	g_pGameRules = reinterpret_cast<void **>(addr);
-}
 #endif
+}
 
 size_t UTIL_StringToSignature(const char *str, char buffer[], size_t maxlength)
 {
diff --git a/extensions/sdktools/vhelpers.cpp b/extensions/sdktools/vhelpers.cpp
index 1c25c742..0f6035c6 100644
--- a/extensions/sdktools/vhelpers.cpp
+++ b/extensions/sdktools/vhelpers.cpp
@@ -241,13 +241,8 @@ int GetClientAimTarget(edict_t *pEdict, bool only_players)
 		return -1;
 	}
 
-	edict_t *pTarget = gameents->BaseEntityToEdict(tr.m_pEnt);
-	if (pTarget == NULL)
-	{
-		return -1;
-	}
-
-	int ent_index = IndexOfEdict(pTarget);
+	int ent_ref = gamehelpers->EntityToBCompatRef(tr.m_pEnt);
+	int ent_index = gamehelpers->ReferenceToIndex(ent_ref);
 
 	IGamePlayer *pTargetPlayer = playerhelpers->GetGamePlayer(ent_index);
 	if (pTargetPlayer != NULL && !pTargetPlayer->IsInGame())
@@ -259,7 +254,7 @@ int GetClientAimTarget(edict_t *pEdict, bool only_players)
 		return -1;
 	}
 
-	return ent_index;
+	return ent_ref;
 }
 
 bool IsEyeAnglesSupported()
diff --git a/extensions/sdktools/vnatives.cpp b/extensions/sdktools/vnatives.cpp
index 7fb4c59f..aee2dd02 100644
--- a/extensions/sdktools/vnatives.cpp
+++ b/extensions/sdktools/vnatives.cpp
@@ -164,18 +164,7 @@ static cell_t GiveNamedItem(IPluginContext *pContext, const cell_t *params)
 	DECODE_VALVE_PARAM(3, vparams, 1);
 	FINISH_CALL_SIMPLE(&pEntity);
 
-	if (pEntity == NULL)
-	{
-		return -1;
-	}
-
-	edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-	if (!pEdict)
-	{
-		return -1;
-	}
-
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(pEntity);
 }
 
 static cell_t GetPlayerWeaponSlot(IPluginContext *pContext, const cell_t *params)
@@ -200,18 +189,7 @@ static cell_t GetPlayerWeaponSlot(IPluginContext *pContext, const cell_t *params
 	DECODE_VALVE_PARAM(2, vparams, 0);
 	FINISH_CALL_SIMPLE(&pEntity);
 
-	if (pEntity == NULL)
-	{
-		return -1;
-	}
-
-	edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-	if (!pEdict)
-	{
-		return -1;
-	}
-
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(pEntity);
 }
 
 #if SOURCE_ENGINE != SE_DARKMESSIAH
@@ -389,7 +367,7 @@ static cell_t SetClientViewEntity(IPluginContext *pContext, const cell_t *params
 		return pContext->ThrowNativeError("Client %d is not in game", params[1]);
 	}
 
-	edict_t *pEdict = PEntityOfEntIndex(params[2]);
+	edict_t *pEdict = PEntityOfEntIndex(gamehelpers->ReferenceToIndex(params[1]));
 	if (!pEdict || pEdict->IsFree())
 	{
 		return pContext->ThrowNativeError("Entity %d is not valid", params[2]);
@@ -477,13 +455,12 @@ static cell_t SlapPlayer(IPluginContext *pContext, const cell_t *params)
 	}
 
 	/* First check if the client is valid */
-	int client = params[1];
-	IGamePlayer *player = playerhelpers->GetGamePlayer(client);
+	IGamePlayer *player = playerhelpers->GetGamePlayer(params[1]);
 	if (!player)
 	{
-		return pContext->ThrowNativeError("Client %d is not valid", client);
+		return pContext->ThrowNativeError("Client %d is not valid", params[1]);
 	} else if (!player->IsInGame()) {
-		return pContext->ThrowNativeError("Client %d is not in game", client);
+		return pContext->ThrowNativeError("Client %d is not in game", params[1]);
 	}
 
 	edict_t *pEdict = player->GetEdict();
@@ -551,7 +528,7 @@ static cell_t SlapPlayer(IPluginContext *pContext, const cell_t *params)
 			CellRecipientFilter rf;
 			rf.SetToReliable(true);
 			rf.Initialize(player_list, total_players);
-			engsound->EmitSound(rf, client, CHAN_AUTO, sound_name, VOL_NORM, ATTN_NORM, 0, PITCH_NORM, &pos);
+			engsound->EmitSound(rf, params[1], CHAN_AUTO, sound_name, VOL_NORM, ATTN_NORM, 0, PITCH_NORM, &pos);
 		}
 	}
 
@@ -619,16 +596,15 @@ static cell_t GetClientEyePosition(IPluginContext *pContext, const cell_t *param
 
 static cell_t GetClientEyeAngles(IPluginContext *pContext, const cell_t *params)
 {
-	int client = params[1];
-	IGamePlayer *pPlayer = playerhelpers->GetGamePlayer(client);
+	IGamePlayer *pPlayer = playerhelpers->GetGamePlayer(params[1]);
 
 	if (!pPlayer)
 	{
-		return pContext->ThrowNativeError("Invalid client index %d", client);
+		return pContext->ThrowNativeError("Invalid client index %d", params[1]);
 	}
 	else if (!pPlayer->IsInGame())
 	{
-		return pContext->ThrowNativeError("Client %d is not in game", client);
+		return pContext->ThrowNativeError("Client %d is not in game", params[1]);
 	}
 
 	edict_t *pEdict = pPlayer->GetEdict();
@@ -678,18 +654,7 @@ static cell_t FindEntityByClassname(IPluginContext *pContext, const cell_t *para
 	DECODE_VALVE_PARAM(2, vparams, 1);
 	FINISH_CALL_SIMPLE(&pEntity);
 
-	if (pEntity == NULL)
-	{
-		return -1;
-	}
-
-	edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-	if (!pEdict)
-	{
-		return -1;
-	}
-
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(pEntity);
 }
 
 #if SOURCE_ENGINE == SE_LEFT4DEAD
@@ -718,18 +683,7 @@ static cell_t CreateEntityByName(IPluginContext *pContext, const cell_t *params)
 	*(bool *)(vptr + 8) = true;
 	FINISH_CALL_SIMPLE(&pEntity);
 
-	if (pEntity == NULL)
-	{
-		return -1;
-	}
-
-	edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-	if (!pEdict)
-	{
-		return -1;
-	}
-
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(pEntity);
 }
 #else
 static cell_t CreateEntityByName(IPluginContext *pContext, const cell_t *params)
@@ -755,18 +709,7 @@ static cell_t CreateEntityByName(IPluginContext *pContext, const cell_t *params)
 	DECODE_VALVE_PARAM(2, vparams, 1);
 	FINISH_CALL_SIMPLE(&pEntity);
 
-	if (pEntity == NULL)
-	{
-		return -1;
-	}
-
-	edict_t *pEdict = gameents->BaseEntityToEdict(pEntity);
-	if (!pEdict)
-	{
-		return -1;
-	}
-
-	return IndexOfEdict(pEdict);
+	return gamehelpers->EntityToBCompatRef(pEntity);
 }
 #endif
 
@@ -881,16 +824,15 @@ static cell_t DispatchKeyValueVector(IPluginContext *pContext, const cell_t *par
 
 static cell_t sm_GetClientAimTarget(IPluginContext *pContext, const cell_t *params)
 {
-	int client = params[1];
-	IGamePlayer *pPlayer = playerhelpers->GetGamePlayer(client);
+	IGamePlayer *pPlayer = playerhelpers->GetGamePlayer(params[1]);
 
 	if (!pPlayer)
 	{
-		return pContext->ThrowNativeError("Invalid client index %d", client);
+		return pContext->ThrowNativeError("Invalid client index %d", params[1]);
 	}
 	else if (!pPlayer->IsInGame())
 	{
-		return pContext->ThrowNativeError("Client %d is not in game", client);
+		return pContext->ThrowNativeError("Client %d is not in game", params[1]);
 	}
 
 	return GetClientAimTarget(pPlayer->GetEdict(), params[2] ? true : false);
diff --git a/extensions/sdktools/vsound.cpp b/extensions/sdktools/vsound.cpp
index 224d5c50..51aefe07 100644
--- a/extensions/sdktools/vsound.cpp
+++ b/extensions/sdktools/vsound.cpp
@@ -383,7 +383,7 @@ static cell_t EmitAmbientSound(IPluginContext *pContext, const cell_t *params)
 	float vol, delay;
 	int pitch, flags, level;
 
-	entity = params[3];
+	entity = gamehelpers->ReferenceToIndex(params[3]);
 
 	cell_t *addr;
 	pContext->LocalToPhysAddr(params[2], &addr);
@@ -436,7 +436,7 @@ static cell_t FadeClientVolume(IPluginContext *pContext, const cell_t *params)
 
 static cell_t StopSound(IPluginContext *pContext, const cell_t *params)
 {
-	int entity = params[1];
+	int entity = gamehelpers->ReferenceToIndex(params[1]);
 	int channel = params[2];
 
 	char *name;
@@ -477,7 +477,7 @@ static cell_t EmitSound(IPluginContext *pContext, const cell_t *params)
 	char *sample;
 	pContext->LocalToString(params[3], &sample);
 	
-	int entity = params[4];
+	int entity = gamehelpers->ReferenceToIndex(params[4]);
 	int channel = params[5];
 	int level = params[6];
 	int flags = params[7];
@@ -648,7 +648,7 @@ static cell_t EmitSentence(IPluginContext *pContext, const cell_t *params)
 	crf.Initialize(addr, numClients);
 
 	int sentence = params[3];
-	int entity = params[4];
+	int entity = gamehelpers->ReferenceToIndex(params[4]);
 	int channel = params[5];
 	int level = params[6];
 	int flags = params[7];
diff --git a/gamedata/core.games/engine.darkm.txt b/gamedata/core.games/engine.darkm.txt
new file mode 100644
index 00000000..d84d54b3
--- /dev/null
+++ b/gamedata/core.games/engine.darkm.txt
@@ -0,0 +1,46 @@
+/**
+ * Do not edit this file.  Any changes will be overwritten by the gamedata
+ * updater or by upgrading your SourceMod install.
+ *
+ * To override data in this file, create a subdirectory named "custom" and
+ * place your own gamedata file(s) inside of it.  Such files will be parsed
+ * after SM's own.
+ *
+ * For more information, see http://wiki.alliedmods.net/Gamedata_Updating_(SourceMod)
+ */
+
+"Games"
+{
+	/* CGlobalEntityList */
+	"#default"
+	{
+		"#supported"
+		{
+			"game"		"!Might and Magic Multiplayer"
+		}
+		
+		"Offsets"
+		{
+			/* Offset into LevelShutdown */
+			"gEntList"
+			{
+				"windows"	"11"
+			}
+
+			"EntInfo"
+			{
+				"windows"	"4"	
+				"linux"		"4"
+			}
+		}
+		
+		"Signatures"
+		{
+			"LevelShutdown"
+			{
+				"library"	"server"
+				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
+			}
+		}
+	}
+}
diff --git a/gamedata/core.games/engine.ep1.txt b/gamedata/core.games/engine.ep1.txt
new file mode 100644
index 00000000..ce4def20
--- /dev/null
+++ b/gamedata/core.games/engine.ep1.txt
@@ -0,0 +1,62 @@
+/**
+ * Do not edit this file.  Any changes will be overwritten by the gamedata
+ * updater or by upgrading your SourceMod install.
+ *
+ * To override data in this file, create a subdirectory named "custom" and
+ * place your own gamedata file(s) inside of it.  Such files will be parsed
+ * after SM's own.
+ *
+ * For more information, see http://wiki.alliedmods.net/Gamedata_Updating_(SourceMod)
+ */
+
+"Games"
+{
+	/* CGlobalEntityList */
+	"#default"
+	{
+		"#supported"
+		{
+			"game"		"cstrike"
+			"game"		"garrysmod"
+			"game"		"hl2mp"
+			"game"		"ship"
+			"game"		"insurgency"
+			"game"		"pvkii"
+			"game"		"sourceforts"
+			"game"		"FortressForever"
+			"game"		"empires"
+			"game"		"synergy"
+			"game"		"hidden"
+			"game"		"zombie_master"
+		}
+		
+		"Offsets"
+		{
+			/* Offset into LevelShutdown */
+			"gEntList"
+			{
+				"windows"	"11"
+			}
+
+			"EntInfo"
+			{
+				"windows"	"4"	
+				"linux"		"4"
+			}
+		}
+		
+		"Signatures"
+		{
+			"LevelShutdown"
+			{
+				"library"	"server"
+				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
+			}
+			"gEntList"
+			{
+				"library"	"server"
+				"linux"		"@gEntList"
+			}
+		}
+	}
+}
diff --git a/gamedata/core.games/engine.ep2.txt b/gamedata/core.games/engine.ep2.txt
new file mode 100644
index 00000000..74a698ba
--- /dev/null
+++ b/gamedata/core.games/engine.ep2.txt
@@ -0,0 +1,54 @@
+/**
+ * Do not edit this file.  Any changes will be overwritten by the gamedata
+ * updater or by upgrading your SourceMod install.
+ *
+ * To override data in this file, create a subdirectory named "custom" and
+ * place your own gamedata file(s) inside of it.  Such files will be parsed
+ * after SM's own.
+ *
+ * For more information, see http://wiki.alliedmods.net/Gamedata_Updating_(SourceMod)
+ */
+
+"Games"
+{
+	/* CGlobalEntityList */
+	"#default"
+	{
+		"#supported"
+		{
+			"game"		"dod"
+			"game"		"tf"
+			"game"		"ageofchivalry"
+			"game"		"ZPS"
+		}
+		
+		"Offsets"
+		{
+			/* Offset into LevelShutdown */
+			"gEntList"
+			{
+				"windows"	"11"
+			}
+
+			"EntInfo"
+			{
+				"windows"	"4"	
+				"linux"		"4"
+			}
+		}
+		
+		"Signatures"
+		{
+			"LevelShutdown"
+			{
+				"library"	"server"
+				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
+			}
+			"gEntList"
+			{
+				"library"	"server"
+				"linux"		"@gEntList"
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/gamedata/core.games/engine.l4d.txt b/gamedata/core.games/engine.l4d.txt
new file mode 100644
index 00000000..b8c09ce7
--- /dev/null
+++ b/gamedata/core.games/engine.l4d.txt
@@ -0,0 +1,51 @@
+/**
+ * Do not edit this file.  Any changes will be overwritten by the gamedata
+ * updater or by upgrading your SourceMod install.
+ *
+ * To override data in this file, create a subdirectory named "custom" and
+ * place your own gamedata file(s) inside of it.  Such files will be parsed
+ * after SM's own.
+ *
+ * For more information, see http://wiki.alliedmods.net/Gamedata_Updating_(SourceMod)
+ */
+
+"Games"
+{
+	/* CGlobalEntityList */
+	"#default"
+	{
+		"#supported"
+		{
+			"game"		"left4dead"
+		}
+		
+		"Offsets"
+		{
+			/* Offset into LevelShutdown */
+			"gEntList"
+			{
+				"windows"	"11"
+			}
+
+			"EntInfo"
+			{
+				"windows"	"4"	
+				"linux"		"4"
+			}
+		}
+		
+		"Signatures"
+		{
+			"LevelShutdown"
+			{
+				"library"	"server"
+				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
+			}
+			"gEntList"
+			{
+				"library"	"server"
+				"linux"		"@gEntList"
+			}
+		}
+	}
+}
diff --git a/gamedata/core.games/master.games.txt b/gamedata/core.games/master.games.txt
index 370491dd..0c554aff 100644
--- a/gamedata/core.games/master.games.txt
+++ b/gamedata/core.games/master.games.txt
@@ -14,4 +14,25 @@
 	"common.games.txt"
 	{
 	}
-}
+
+	"engine.l4d.txt"
+	{
+		"engine"	"left4dead"
+	}
+	
+	"engine.ep2.txt"
+	{
+		"engine"	"orangebox"
+	}
+	
+	"engine.ep1.txt"
+	{
+		"engine"	"original"
+	}
+	
+	"engine.darkm.txt"
+	{
+		"engine"	"darkmessiah"
+	}
+
+}
\ No newline at end of file
diff --git a/gamedata/sdktools.games/engine.darkm.txt b/gamedata/sdktools.games/engine.darkm.txt
index fae2c01b..a0969526 100644
--- a/gamedata/sdktools.games/engine.darkm.txt
+++ b/gamedata/sdktools.games/engine.darkm.txt
@@ -105,24 +105,9 @@
 		{
 			"game"		"!Might and Magic Multiplayer"
 		}
-		
-		"Offsets"
-		{
-			/* Offset into LevelShutdown */
-			"gEntList"
-			{
-				"windows"	"11"
-			}
-		}
-		
+				
 		"Signatures"
 		{
-			"LevelShutdown"
-			{
-				"library"	"server"
-				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
-			}
-
 			/* Functions in CGlobalEntityList */
 			"FindEntityByClassname"
 			{
@@ -239,7 +224,7 @@
 			/**
 			 * CBaseClient::SetUserCVar(char  const*,char  const*);
 			 * Linux offset straight from VTable dump.
-			 * Windows offset is crazy. Found the windows 'SetName' function using string "(%d)%-0.*s"
+			 * Windows offset is crazy. Found the windows SetName function using string "(%d)%-0.*s"
 			 * Cross referenced back to the vtable and counted manually (SetUserCvar is 1 higher, offsets start from 1)
 			 */
 			"SetUserCvar"
diff --git a/gamedata/sdktools.games/engine.ep1.txt b/gamedata/sdktools.games/engine.ep1.txt
index c2a2f435..337e5069 100644
--- a/gamedata/sdktools.games/engine.ep1.txt
+++ b/gamedata/sdktools.games/engine.ep1.txt
@@ -139,28 +139,8 @@
 			"game"		"zombie_master"
 		}
 		
-		"Offsets"
-		{
-			/* Offset into LevelShutdown */
-			"gEntList"
-			{
-				"windows"	"11"
-			}
-		}
-		
 		"Signatures"
-		{
-			"LevelShutdown"
-			{
-				"library"	"server"
-				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
-			}
-			"gEntList"
-			{
-				"library"	"server"
-				"linux"		"@gEntList"
-			}
-			
+		{	
 			/* Functions in CGlobalEntityList */
 			"FindEntityByClassname"
 			{
@@ -288,7 +268,7 @@
 			/**
 			 * CBaseClient::SetUserCVar(char  const*,char  const*);
 			 * Linux offset straight from VTable dump.
-			 * Windows offset is crazy. Found the windows 'SetName' function using string "(%d)%-0.*s"
+			 * Windows offset is crazy. Found the windows SetName function using string "(%d)%-0.*s"
 			 * Cross referenced back to the vtable and counted manually (SetUserCvar is 1 higher, offsets start from 1)
 			 */
 			"SetUserCvar"
diff --git a/gamedata/sdktools.games/engine.ep2.txt b/gamedata/sdktools.games/engine.ep2.txt
index c40722bc..7216f73c 100644
--- a/gamedata/sdktools.games/engine.ep2.txt
+++ b/gamedata/sdktools.games/engine.ep2.txt
@@ -100,28 +100,8 @@
 			"game"		"ZPS"
 		}
 		
-		"Offsets"
-		{
-			/* Offset into LevelShutdown */
-			"gEntList"
-			{
-				"windows"	"11"
-			}
-		}
-		
 		"Signatures"
 		{
-			"LevelShutdown"
-			{
-				"library"	"server"
-				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
-			}
-			"gEntList"
-			{
-				"library"	"server"
-				"linux"		"@gEntList"
-			}
-			
 			/* Functions in CGlobalEntityList */
 			"FindEntityByClassname"
 			{
@@ -261,7 +241,7 @@
 			/**
 			 * CBaseClient::SetUserCVar(char  const*,char  const*);
 			 * Linux offset straight from VTable dump.
-			 * Windows offset is crazy. Found the windows 'SetName' function using string "(%d)%-0.*s"
+			 * Windows offset is crazy. Found the windows SetName function using string "(%d)%-0.*s"
 			 * Cross referenced back to the vtable and counted manually (SetUserCvar is 1 higher, offsets start from 1)
 			 */
 			"SetUserCvar"
diff --git a/gamedata/sdktools.games/engine.l4d.txt b/gamedata/sdktools.games/engine.l4d.txt
index a18ca0f1..62fbd3af 100644
--- a/gamedata/sdktools.games/engine.l4d.txt
+++ b/gamedata/sdktools.games/engine.l4d.txt
@@ -101,29 +101,9 @@
 		{
 			"game"		"left4dead"
 		}
-		
-		"Offsets"
-		{
-			/* Offset into LevelShutdown */
-			"gEntList"
-			{
-				"windows"	"11"
-			}
-		}
-		
+			
 		"Signatures"
 		{
-			"LevelShutdown"
-			{
-				"library"	"server"
-				"windows"	"\xE8\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xB9\x2A\x2A\x2A\x2A\xE8\x2A\x2A\x2A\x2A\xE8"
-			}
-			"gEntList"
-			{
-				"library"	"server"
-				"linux"		"@gEntList"
-			}
-			
 			/* Functions in CGlobalEntityList */
 			"FindEntityByClassname"
 			{
@@ -258,7 +238,7 @@
 			/**
 			 * CBaseClient::SetUserCVar(char  const*,char  const*);
 			 * Linux offset straight from VTable dump.
-			 * Windows offset is crazy. Found the windows 'SetName' function using string "(%d)%-0.*s"
+			 * Windows offset is crazy. Found the windows SetName function using string "(%d)%-0.*s"
 			 * Cross referenced back to the vtable and counted manually (SetUserCvar is 1 higher, offsets start from 1)
 			 */
 			"SetUserCvar"
diff --git a/plugins/include/halflife.inc b/plugins/include/halflife.inc
index 1d59a188..b40807b0 100644
--- a/plugins/include/halflife.inc
+++ b/plugins/include/halflife.inc
@@ -56,6 +56,8 @@ enum DialogType
 	DialogType_AskConnect	/**< ask the client to connect to a specified IP */
 };
 
+#define INVALID_ENT_REFERENCE 0xFFFFFFFF
+
 /**
  * Logs a generic message to the HL2 logs.
  *
@@ -544,3 +546,28 @@ stock DisplayAskConnectBox(client, Float:time, const String:ip[])
 	CreateDialog(client, Kv, DialogType_AskConnect);
 	CloseHandle(Kv);
 }
+
+/**
+ * Converts an entity index into a serial encoded entity reference.
+ *
+ * @param entity		Entity index.
+ * @return				Entity reference.
+ */
+native EntIndexToEntRef(entity);
+
+/**
+ * Retrieves the entity index from a reference.
+ *
+ * @param ref			Entity reference.
+ * @return				Entity index.
+ */
+native EntRefToEntIndex(ref);
+
+/**
+ * Converts a reference into a backwards compatible version.
+ *
+ * @param ref			Entity reference.
+ * @return				Bcompat reference.
+ */
+native MakeCompatEntRef(ref);
+
diff --git a/public/IGameHelpers.h b/public/IGameHelpers.h
index 8bf5a751..19d59871 100644
--- a/public/IGameHelpers.h
+++ b/public/IGameHelpers.h
@@ -193,6 +193,63 @@ namespace SourceMod
 		 * @param buffer		Command buffer (does not auto \n terminate).
 		 */
 		virtual void ServerCommand(const char *buffer) =0;
+
+		/**
+		 * @brief Looks up a reference and returns the CBasseEntity* it points to.
+		 *
+		 * @note Supports 'old style' simple indexes and does a serial confirmation check on references.
+		 *
+		 * @param entRef		Entity reference.
+		 * @return				Entity pointer.
+		 */
+		virtual CBaseEntity *ReferenceToEntity(cell_t entRef) =0;
+
+		/**
+		 * @brief Returns the entity reference for an entity.
+		 *
+		 * @param pEntity		Entity pointer.
+		 * @return				Entity reference.
+		 */
+		virtual cell_t EntityToReference(CBaseEntity *pEntity) =0;
+
+		/**
+		 * @brief Returns the entity reference for logical entities, or the index for networked entities.
+		 *
+		 * @param pEntity		Entity pointer.
+		 * @return				Entity reference/index.
+		 */
+		virtual cell_t EntityToBCompatRef(CBaseEntity *pEntity) =0;
+
+		/**
+		 * @brief Converts an entity index into an entity reference.
+		 *
+		 * @param entIndex		Entity index.
+		 * @return				Entity reference.
+		 */
+		virtual cell_t IndexToReference(int entIndex) =0;
+
+		/**
+		 * @brief Retrieves the entity index from a reference.
+		 *
+		 * @param entRef		Entity reference.
+		 * @return				Entity index.
+		 */
+		virtual int ReferenceToIndex(cell_t entRef) =0;
+
+		/**
+		 * @brief Converts a reference into a bcompat version (index for networked entities).
+		 *
+		 * @param entRef		Entity reference.
+		 * @return				Entity reference/index.
+		 */
+		virtual cell_t ReferenceToBCompatRef(cell_t entRef) =0;
+		
+		/**
+		 * @brief Returns the g_EntList pointer.
+		 *
+		 * @return				g_EntList pointer.
+		 */
+		virtual void *GetGlobalEntityList() =0;
 	};
 }