diff --git a/Sources/Plasma/CoreLib/hsThread.cpp b/Sources/Plasma/CoreLib/hsThread.cpp
index 6c455469..d36f8bb5 100644
--- a/Sources/Plasma/CoreLib/hsThread.cpp
+++ b/Sources/Plasma/CoreLib/hsThread.cpp
@@ -57,14 +57,14 @@ hsReaderWriterLock::hsReaderWriterLock(Callback * cb)
 void hsReaderWriterLock::LockForReading()
 {
     if ( fCallback )
-        fCallback->OnLockingForRead( this );
-    fReaderCountLock.Lock();
-    fReaderLock.Lock();
-    fReaderCount++;
-    if ( fReaderCount==1 )
-        fWriterSema.Wait();
-    fReaderLock.Unlock();
-    fReaderCountLock.Unlock();
+        fCallback->OnLockingForRead(this);
+    {
+        std::lock_guard<std::mutex> lock_count(fReaderCountLock);
+        std::lock_guard<std::mutex> lock(fReaderLock);
+        fReaderCount++;
+        if (fReaderCount == 1)
+            fWriterSema.Wait();
+    }
     if ( fCallback )
         fCallback->OnLockedForRead( this );
 }
@@ -72,12 +72,13 @@ void hsReaderWriterLock::LockForReading()
 void hsReaderWriterLock::UnlockForReading()
 {
     if ( fCallback )
-        fCallback->OnUnlockingForRead( this );
-    fReaderLock.Lock();
-    fReaderCount--;
-    if ( fReaderCount==0 )
-        fWriterSema.Signal();
-    fReaderLock.Unlock();
+        fCallback->OnUnlockingForRead(this);
+    {
+        std::lock_guard<std::mutex> lock(fReaderLock);
+        fReaderCount--;
+        if (fReaderCount == 0)
+            fWriterSema.Signal();
+    }
     if ( fCallback )
         fCallback->OnUnlockedForRead( this );
 }
@@ -86,7 +87,7 @@ void hsReaderWriterLock::LockForWriting()
 {
     if ( fCallback )
         fCallback->OnLockingForWrite( this );
-    fReaderCountLock.Lock();
+    fReaderCountLock.lock();
     fWriterSema.Wait();
     hsAssert( fReaderCount==0, "Locked for writing, but fReaderCount>0" );
     if ( fCallback )
@@ -98,7 +99,7 @@ void hsReaderWriterLock::UnlockForWriting()
     if ( fCallback )
         fCallback->OnUnlockingForWrite( this );
     fWriterSema.Signal();
-    fReaderCountLock.Unlock();
+    fReaderCountLock.unlock();
     if ( fCallback )
         fCallback->OnUnlockedForWrite( this );
 }
diff --git a/Sources/Plasma/CoreLib/hsThread.h b/Sources/Plasma/CoreLib/hsThread.h
index 88ff8e89..d45625f6 100644
--- a/Sources/Plasma/CoreLib/hsThread.h
+++ b/Sources/Plasma/CoreLib/hsThread.h
@@ -43,6 +43,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #define hsThread_Defined
 
 #include "HeadSpin.h"
+#include <mutex>
 
 typedef uint32_t hsMilliseconds;
 
@@ -106,44 +107,6 @@ public:
 
 //////////////////////////////////////////////////////////////////////////////
 
-class hsMutex {
-#if HS_BUILD_FOR_WIN32
-    HANDLE  fMutexH;
-#elif HS_BUILD_FOR_UNIX
-    pthread_mutex_t fPMutex;
-#endif
-public:
-    hsMutex();
-    virtual ~hsMutex();
-
-#ifdef HS_BUILD_FOR_WIN32
-    HANDLE GetHandle() const { return fMutexH; }
-#endif
-
-    void        Lock();
-    bool        TryLock();
-    void        Unlock();
-};
-
-class hsTempMutexLock {
-    hsMutex*    fMutex;
-public:
-    hsTempMutexLock(hsMutex* mutex) : fMutex(mutex)
-    {
-        fMutex->Lock();
-    }
-    hsTempMutexLock(hsMutex& mutex) : fMutex(&mutex)
-    {
-        fMutex->Lock();
-    }
-    ~hsTempMutexLock()
-    {
-        fMutex->Unlock();
-    }
-};
-
-//////////////////////////////////////////////////////////////////////////////
-
 class hsSemaphore {
 #if HS_BUILD_FOR_WIN32
     HANDLE  fSemaH;
@@ -181,8 +144,8 @@ class hsEvent
 #else
     enum { kRead, kWrite };
     int     fFds[2];
-    hsMutex fWaitLock;
-    hsMutex fSignalLock;
+    std::mutex fWaitLock;
+    std::mutex fSignalLock;
 #endif // PSEUDO_EVENT
 #elif HS_BUILD_FOR_WIN32
     HANDLE fEvent;
@@ -231,8 +194,8 @@ public:
 
 private:
     int     fReaderCount;
-    hsMutex fReaderCountLock;
-    hsMutex fReaderLock;
+    std::mutex  fReaderCountLock;
+    std::mutex  fReaderLock;
     hsSemaphore fWriterSema;
     Callback *  fCallback;
 };
diff --git a/Sources/Plasma/CoreLib/hsThread_Mac.cpp b/Sources/Plasma/CoreLib/hsThread_Mac.cpp
index f7a9594e..9429604d 100644
--- a/Sources/Plasma/CoreLib/hsThread_Mac.cpp
+++ b/Sources/Plasma/CoreLib/hsThread_Mac.cpp
@@ -115,32 +115,6 @@ void hsThread::ThreadYield()
 
 //////////////////////////////////////////////////////////////////////////////
 
-hsMutex::hsMutex()
-{
-    OSStatus status = ::MPCreateCriticalRegion(&fCriticalRegion);
-    hsThrowIfOSErr(status);
-}
-
-hsMutex::~hsMutex()
-{
-    OSStatus    status = ::MPDeleteCriticalRegion(fCriticalRegion);
-    hsThrowIfOSErr(status);
-}
-
-void hsMutex::Lock()
-{
-    OSStatus    status = ::MPEnterCriticalRegion(fCriticalRegion, kDurationForever);
-    hsThrowIfOSErr(status);
-}
-
-void hsMutex::Unlock()
-{
-    OSStatus    status = ::MPExitCriticalRegion(fCriticalRegion);
-    hsThrowIfOSErr(status);
-}
-
-//////////////////////////////////////////////////////////////////////////////
-
 hsSemaphore::hsSemaphore(int initialValue)
 {
     OSStatus    status = MPCreateSemaphore(kPosInfinity32, initialValue, &fSemaId);
diff --git a/Sources/Plasma/CoreLib/hsThread_Unix.cpp b/Sources/Plasma/CoreLib/hsThread_Unix.cpp
index 786ced38..c6eb1a09 100644
--- a/Sources/Plasma/CoreLib/hsThread_Unix.cpp
+++ b/Sources/Plasma/CoreLib/hsThread_Unix.cpp
@@ -190,83 +190,6 @@ static void InitEventLoggingFile()
 
 #endif
 
-hsMutex::hsMutex()
-{
-
-#ifdef MUTEX_TIMING
-    InitMutexTimerFile();
-#endif
-
-    // create mutex attributes
-    pthread_mutexattr_t attr;
-    int status = ::pthread_mutexattr_init(&attr);
-    hsThrowIfOSErr(status);
-
-    // make the mutex attributes recursive
-    status = ::pthread_mutexattr_settype(&attr,PTHREAD_MUTEX_RECURSIVE);
-    hsThrowIfOSErr(status);
-
-    //init the mutex
-    status = ::pthread_mutex_init(&fPMutex, &attr);
-    hsThrowIfOSErr(status);
-
-    // destroy the attributes
-    status = ::pthread_mutexattr_destroy(&attr);
-    hsThrowIfOSErr(status);
-}
-
-hsMutex::~hsMutex()
-{
-    int status = ::pthread_mutex_destroy(&fPMutex);
-    hsThrowIfOSErr(status);
-}
-
-void hsMutex::Lock()
-{
-#ifdef MUTEX_TIMING
-# ifndef HS_DEBUGGING
-    timeval tv;
-    hsWide start;
-    gettimeofday( &tv, nil );
-    start.Mul( tv.tv_sec, 1000000 )->Add( tv.tv_usec );
-# endif
-#endif
-
-    int status = ::pthread_mutex_lock(&fPMutex);
-    hsThrowIfOSErr(status);
-
-#ifdef MUTEX_TIMING
-# ifndef HS_DEBUGGING
-    hsWide diff;
-    gettimeofday( &tv, nil );
-    diff.Mul( tv.tv_sec, 1000000 )->Add( tv.tv_usec )->Sub( &start )->Div( 1000000 );
-    double duration = diff.AsDouble();
-    if ( gMutexTimerFile && duration>0.005 )
-    {
-        time_t t;
-        time( &t );
-        struct tm *now = localtime( &t );
-        char tmp[30];
-        strftime( tmp, 30, "%c", now );
-        fprintf( gMutexTimerFile, "[%s] [%lu:%lu] %f\n", tmp, getpid(), hsThread::GetMyThreadId(), duration );
-    }
-# endif
-#endif
-}
-
-bool hsMutex::TryLock()
-{
-    int status = ::pthread_mutex_trylock(&fPMutex);
-    hsThrowIfOSErr(status);
-    return status==EBUSY?false:true;
-}
-
-void hsMutex::Unlock()
-{
-    int status = ::pthread_mutex_unlock(&fPMutex);
-    hsThrowIfOSErr(status);
-}
-
 /////////////////////////////////////////////////////////////////////////////
 
 hsSemaphore::hsSemaphore(int initialValue, const char* name)
@@ -538,7 +461,7 @@ hsEvent::~hsEvent()
 
 bool hsEvent::Wait( hsMilliseconds timeToWait )
 {
-    hsTempMutexLock lock( fWaitLock );
+    std::lock_guard<std::mutex> lock(fWaitLock);
 
     fd_set  fdset;
     FD_ZERO( &fdset );
@@ -572,7 +495,7 @@ bool hsEvent::Wait( hsMilliseconds timeToWait )
 
 void hsEvent::Signal()
 {
-    hsTempMutexLock lock( fSignalLock );
+    std::lock_guard<std::mutex> lock(fSignalLock);
     write( fFds[kWrite], "*", 1 );
 }
 
diff --git a/Sources/Plasma/CoreLib/hsThread_Win.cpp b/Sources/Plasma/CoreLib/hsThread_Win.cpp
index 4fb4e3c8..90f7d617 100644
--- a/Sources/Plasma/CoreLib/hsThread_Win.cpp
+++ b/Sources/Plasma/CoreLib/hsThread_Win.cpp
@@ -135,42 +135,6 @@ void hsThread::ThreadYield()
 
 //////////////////////////////////////////////////////////////////////////////
 
-hsMutex::hsMutex()
-{
-    fMutexH = ::CreateMutex(nil, false, nil);
-    if (fMutexH == nil)
-        throw hsOSException(-1);
-}
-
-hsMutex::~hsMutex()
-{
-    ::CloseHandle(fMutexH);
-}
-
-void hsMutex::Lock()
-{
-    DWORD state = ::WaitForSingleObject(fMutexH, INFINITE);
-    hsAssert(state != WAIT_FAILED,"hsMutex::Lock -> Wait Failed");
-    hsAssert(state != WAIT_ABANDONED,"hsMutex::Lock -> Abandoned Mutex");
-    hsAssert(state != WAIT_TIMEOUT,"hsMutex::Lock -> Infinite Timeout expired?");
-}
-
-bool hsMutex::TryLock()
-{
-    DWORD state = ::WaitForSingleObject(fMutexH, 0);
-    hsAssert(state != WAIT_ABANDONED,"hsMutex::TryLock -> Abandoned Mutex");
-    return state == WAIT_OBJECT_0?true:false;
-}
-
-void hsMutex::Unlock()
-{
-    BOOL result = ::ReleaseMutex(fMutexH);
-    hsAssert(result != 0, "hsMutex::Unlock Failed!");
-
-}
-
-//////////////////////////////////////////////////////////////////////////////
-
 hsSemaphore::hsSemaphore(int initialValue, const char *name)
 {
     fSemaH = ::CreateSemaphore(nil, initialValue, kPosInfinity32, name);
diff --git a/Sources/Plasma/FeatureLib/pfPatcher/pfPatcher.cpp b/Sources/Plasma/FeatureLib/pfPatcher/pfPatcher.cpp
index 8e08c3a6..961d386a 100644
--- a/Sources/Plasma/FeatureLib/pfPatcher/pfPatcher.cpp
+++ b/Sources/Plasma/FeatureLib/pfPatcher/pfPatcher.cpp
@@ -42,6 +42,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 
 #include <algorithm>
 #include <deque>
+#include <mutex>
 
 #include "pfPatcher.h"
 
@@ -101,8 +102,8 @@ struct pfPatcherWorker : public hsThread
     std::deque<Request> fRequests;
     std::deque<NetCliFileManifestEntry> fQueuedFiles;
 
-    hsMutex fRequestMut;
-    hsMutex fFileMut;
+    std::mutex fRequestMut;
+    std::mutex fFileMut;
     hsSemaphore fFileSignal;
 
     pfPatcher::CompletionFunc fOnComplete;
@@ -243,7 +244,7 @@ static void IGotAuthFileList(ENetError result, void* param, const NetCliAuthFile
         // so everything goes directly into the Requests deque because AuthSrv lists
         // don't have any hashes attached. WHY did eap think this was a good idea?!?!
         {
-            hsTempMutexLock lock(patcher->fRequestMut);
+            std::lock_guard<std::mutex> lock(patcher->fRequestMut);
             for (unsigned i = 0; i < infoCount; ++i) {
                 PatcherLogYellow("\tEnqueuing Legacy File '%S'", infoArr[i].filename);
 
@@ -268,7 +269,7 @@ static void IHandleManifestDownload(pfPatcherWorker* patcher, const wchar_t grou
 {
     PatcherLogGreen("\tDownloaded Manifest '%S'", group);
     {
-        hsTempMutexLock lock(patcher->fFileMut);
+        std::lock_guard<std::mutex> lock(patcher->fFileMut);
         for (unsigned i = 0; i < entryCount; ++i)
             patcher->fQueuedFiles.push_back(manifest[i]);
         patcher->fFileSignal.Signal();
@@ -287,7 +288,7 @@ static void IPreloaderManifestDownloadCB(ENetError result, void* param, const wc
 
         // so, we need to ask the AuthSrv about our game code
         {
-            hsTempMutexLock lock(patcher->fRequestMut);
+            std::lock_guard<std::mutex> lock(patcher->fRequestMut);
             patcher->fRequests.push_back(pfPatcherWorker::Request(plString::Null, pfPatcherWorker::Request::kPythonList));
             patcher->fRequests.push_back(pfPatcherWorker::Request(plString::Null, pfPatcherWorker::Request::kSdlList));
         }
@@ -341,7 +342,7 @@ pfPatcherWorker::pfPatcherWorker() :
 pfPatcherWorker::~pfPatcherWorker()
 {
     {
-        hsTempMutexLock lock(fRequestMut);
+        std::lock_guard<std::mutex> lock(fRequestMut);
         std::for_each(fRequests.begin(), fRequests.end(),
             [] (const Request& req) {
                 if (req.fStream) req.fStream->Close();
@@ -352,7 +353,7 @@ pfPatcherWorker::~pfPatcherWorker()
     }
 
     {
-        hsTempMutexLock lock(fFileMut);
+        std::lock_guard<std::mutex> lock(fFileMut);
         fQueuedFiles.clear();
     }
 }
@@ -386,7 +387,7 @@ void pfPatcherWorker::EndPatch(ENetError result, const plString& msg)
 
 bool pfPatcherWorker::IssueRequest()
 {
-    hsTempMutexLock lock(fRequestMut);
+    std::lock_guard<std::mutex> lock(fRequestMut);
     if (fRequests.empty()) {
         fRequestActive = false;
         fFileSignal.Signal(); // make sure the patch thread doesn't deadlock!
@@ -451,7 +452,7 @@ hsError pfPatcherWorker::Run()
     do {
         fFileSignal.Wait();
 
-        hsTempMutexLock fileLock(fFileMut);
+        std::lock_guard<std::mutex> fileLock(fFileMut);
         if (!fQueuedFiles.empty()) {
             ProcessFile();
             continue;
@@ -515,8 +516,10 @@ void pfPatcherWorker::ProcessFile()
         pfPatcherStream* s = new pfPatcherStream(this, dlName, entry);
         s->Open(clName, "wb");
 
-        hsTempMutexLock lock(fRequestMut);
-        fRequests.push_back(Request(dlName, Request::kFile, s));
+        {
+            std::lock_guard<std::mutex> lock(fRequestMut);
+            fRequests.push_back(Request(dlName, Request::kFile, s));
+        }
         fQueuedFiles.pop_front();
 
         if (!fRequestActive)
@@ -615,19 +618,19 @@ void pfPatcher::OnSelfPatch(FileDownloadFunc cb)
 
 void pfPatcher::RequestGameCode()
 {
-    hsTempMutexLock lock(fWorker->fRequestMut);
+    std::lock_guard<std::mutex> lock(fWorker->fRequestMut);
     fWorker->fRequests.push_back(pfPatcherWorker::Request("SecurePreloader", pfPatcherWorker::Request::kSecurePreloader));
 }
 
 void pfPatcher::RequestManifest(const plString& mfs)
 {
-    hsTempMutexLock lock(fWorker->fRequestMut);
+    std::lock_guard<std::mutex> lock(fWorker->fRequestMut);
     fWorker->fRequests.push_back(pfPatcherWorker::Request(mfs, pfPatcherWorker::Request::kManifest));
 }
 
 void pfPatcher::RequestManifest(const std::vector<plString>& mfs)
 {
-    hsTempMutexLock lock(fWorker->fRequestMut);
+    std::lock_guard<std::mutex> lock(fWorker->fRequestMut);
     std::for_each(mfs.begin(), mfs.end(),
         [&] (const plString& name) {
             fWorker->fRequests.push_back(pfPatcherWorker::Request(name, pfPatcherWorker::Request::kManifest));
diff --git a/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.cpp b/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.cpp
index 82b0ece8..f28c0853 100644
--- a/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.cpp
+++ b/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.cpp
@@ -84,7 +84,7 @@ public:
     uint32_t                          GetNumReceivers() const { return fReceivers.GetCount(); }
 };
 
-int32_t                   plDispatch::fNumBufferReq = 0;
+int32_t                 plDispatch::fNumBufferReq = 0;
 bool                    plDispatch::fMsgActive = false;
 plMsgWrap*              plDispatch::fMsgCurrent = nil;
 plMsgWrap*              plDispatch::fMsgHead = nil;
@@ -92,8 +92,8 @@ plMsgWrap*              plDispatch::fMsgTail = nil;
 hsTArray<plMessage*>    plDispatch::fMsgWatch;
 MsgRecieveCallback      plDispatch::fMsgRecieveCallback = nil;
 
-hsMutex     plDispatch::fMsgCurrentMutex; // mutex for fMsgCurrent
-hsMutex     plDispatch::fMsgDispatchLock; // mutex for IMsgDispatch
+std::recursive_mutex    plDispatch::fMsgCurrentMutex; // mutex for fMsgCurrent
+std::mutex              plDispatch::fMsgDispatchLock; // mutex for IMsgDispatch
 
 
 plDispatch::plDispatch()
@@ -227,18 +227,19 @@ bool plDispatch::IListeningForExactType(uint16_t hClass)
 
 void plDispatch::IMsgEnqueue(plMsgWrap* msgWrap, bool async)
 {
-    fMsgCurrentMutex.Lock();
+    {
+        std::lock_guard<std::recursive_mutex> lock(fMsgCurrentMutex);
 
 #ifdef HS_DEBUGGING
-    if( msgWrap->fMsg->HasBCastFlag(plMessage::kMsgWatch) )
-        fMsgWatch.Append(msgWrap->fMsg);
+        if (msgWrap->fMsg->HasBCastFlag(plMessage::kMsgWatch))
+            fMsgWatch.Append(msgWrap->fMsg);
 #endif // HS_DEBUGGING
 
-    if( fMsgTail )
-        fMsgTail = IInsertToQueue(&fMsgTail->fNext, msgWrap);
-    else
-        fMsgTail = IInsertToQueue(&fMsgHead, msgWrap);
-    fMsgCurrentMutex.Unlock();
+        if (fMsgTail)
+            fMsgTail = IInsertToQueue(&fMsgTail->fNext, msgWrap);
+        else
+            fMsgTail = IInsertToQueue(&fMsgHead, msgWrap);
+    }
 
     if( !async )
         // Test for fMsgActive in IMsgDispatch(), properly wrapped inside a mutex -mcn
@@ -248,25 +249,22 @@ void plDispatch::IMsgEnqueue(plMsgWrap* msgWrap, bool async)
 // On starts deferring msg delivery until buffering is set to off again.
 bool plDispatch::SetMsgBuffering(bool on)
 {
-    fMsgCurrentMutex.Lock();
-    if( on )
     {
-        hsAssert(fNumBufferReq || !fMsgActive, "Can't start deferring message delivery while delivering messages. See mf");
-        if( !fNumBufferReq && fMsgActive )
+        std::lock_guard<std::recursive_mutex> lock(fMsgCurrentMutex);
+        if (on)
         {
-            fMsgCurrentMutex.Unlock();
-            return false;
-        }
+            hsAssert(fNumBufferReq || !fMsgActive, "Can't start deferring message delivery while delivering messages. See mf");
+            if (!fNumBufferReq && fMsgActive)
+                return false;
 
-        fNumBufferReq++;
-        fMsgActive = true;
-        fMsgCurrentMutex.Unlock();
-    }
-    else if( !--fNumBufferReq )
-    {
-        fMsgActive = false;
-        fMsgCurrentMutex.Unlock();
-        IMsgDispatch();
+            fNumBufferReq++;
+            fMsgActive = true;
+        }
+        else if (!--fNumBufferReq)
+        {
+            fMsgActive = false;
+            IMsgDispatch();
+        }
     }
     hsAssert(fNumBufferReq >= 0, "Mismatched number of on/off dispatch buffering requests");
 
@@ -275,25 +273,25 @@ bool plDispatch::SetMsgBuffering(bool on)
 
 void plDispatch::IMsgDispatch()
 {
-    if( !fMsgDispatchLock.TryLock() )
+    if (!fMsgDispatchLock.try_lock())
         return;
 
     if( fMsgActive )
     {
-        fMsgDispatchLock.Unlock();
+        fMsgDispatchLock.unlock();
         return;
     }
 
     fMsgActive = true;
     int responseLevel=0;
 
-    fMsgCurrentMutex.Lock();
+    fMsgCurrentMutex.lock();
 
     plMsgWrap* origTail = fMsgTail;
     while((fMsgCurrent = fMsgHead))
     {
         IDequeue(&fMsgHead, &fMsgTail);
-        fMsgCurrentMutex.Unlock();
+        fMsgCurrentMutex.unlock();
 
         plMessage* msg = fMsgCurrent->fMsg;
         bool nonLocalMsg = msg && msg->HasBCastFlag(plMessage::kNetNonLocal);
@@ -402,16 +400,16 @@ void plDispatch::IMsgDispatch()
 //          }
 //      }
 
-        fMsgCurrentMutex.Lock();
+        fMsgCurrentMutex.lock();
 
         delete fMsgCurrent;
         // TEMP
         fMsgCurrent = (class plMsgWrap *)0xdeadc0de;
     }
-    fMsgCurrentMutex.Unlock();
+    fMsgCurrentMutex.unlock();
 
     fMsgActive = false;
-    fMsgDispatchLock.Unlock();
+    fMsgDispatchLock.unlock();
 }
 
 //
@@ -419,12 +417,12 @@ void plDispatch::IMsgDispatch()
 //
 bool plDispatch::IMsgNetPropagate(plMessage* msg)
 {
-    fMsgCurrentMutex.Lock();
-
-    // Make sure cascaded messages all have the same net flags
-    plNetClientApp::InheritNetMsgFlags(fMsgCurrent ? fMsgCurrent->fMsg : nil, msg, false);
+    {
+        std::lock_guard<std::recursive_mutex> lock(fMsgCurrentMutex);
 
-    fMsgCurrentMutex.Unlock();
+        // Make sure cascaded messages all have the same net flags
+        plNetClientApp::InheritNetMsgFlags(fMsgCurrent ? fMsgCurrent->fMsg : nil, msg, false);
+    }
 
     // Decide if msg should go out over the network.
     // If kNetForce is used, this message should always go out over the network, even if it's already 
@@ -511,10 +509,9 @@ void plDispatch::MsgQueue(plMessage* msg)
 {
     if (fQueuedMsgOn)
     {
-        fQueuedMsgListMutex.Lock();
+        std::lock_guard<std::mutex> lock(fQueuedMsgListMutex);
         hsAssert(msg,"Message missing");
         fQueuedMsgList.push_back(msg);
-        fQueuedMsgListMutex.Unlock();
     }
     else
         MsgSend(msg, false);
@@ -522,23 +519,23 @@ void plDispatch::MsgQueue(plMessage* msg)
 
 void plDispatch::MsgQueueProcess()
 {
-        // Process all messages on Queue, unlock while sending them
-        // this would allow other threads to put new messages on the list while we send()
-    while (1)
-    {   
-        plMessage * pMsg = nil;
-        fQueuedMsgListMutex.Lock();
-        int size = fQueuedMsgList.size();
-        if (size)
-        {   pMsg = fQueuedMsgList.front();
-            fQueuedMsgList.pop_front();
+    // Process all messages on Queue, unlock while sending them
+    // this would allow other threads to put new messages on the list while we send()
+    bool empty = false;
+    while (!empty)
+    {
+        plMessage * pMsg = nullptr;
+        {
+            std::lock_guard<std::mutex> lock(fQueuedMsgListMutex);
+            empty = fQueuedMsgList.empty();
+            if (!empty)
+            {
+                pMsg = fQueuedMsgList.front();
+                fQueuedMsgList.pop_front();
+            }
         }
-        fQueuedMsgListMutex.Unlock();
         if (pMsg)
-        {   MsgSend(pMsg, false);
-        }
-        if (!size)
-            break;
+            MsgSend(pMsg, false);
     }
 }
 
diff --git a/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.h b/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.h
index a4b31329..9c38bb03 100644
--- a/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.h
+++ b/Sources/Plasma/NucleusLib/pnDispatch/plDispatch.h
@@ -42,7 +42,9 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 
 #ifndef plDispatch_inc
 #define plDispatch_inc
+
 #include <list>
+#include <mutex>
 #include "hsTemplates.h"
 #include "plgDispatch.h"
 #include "hsThread.h"
@@ -74,10 +76,10 @@ protected:
     hsKeyedObject*                  fOwner;
 
     plMsgWrap*                      fFutureMsgQueue;
-    static int32_t                    fNumBufferReq;
+    static int32_t                  fNumBufferReq;
     static plMsgWrap*               fMsgCurrent;
-    static hsMutex                  fMsgCurrentMutex; // mutex for above
-    static hsMutex                  fMsgDispatchLock;   // mutex for IMsgDispatch
+    static std::recursive_mutex     fMsgCurrentMutex; // mutex for above
+    static std::mutex               fMsgDispatchLock;   // mutex for IMsgDispatch
     static plMsgWrap*               fMsgHead;
     static plMsgWrap*               fMsgTail;
     static bool                     fMsgActive;
@@ -86,7 +88,7 @@ protected:
 
     hsTArray<plTypeFilter*>         fRegisteredExactTypes;
     std::list<plMessage*>           fQueuedMsgList;
-    hsMutex                         fQueuedMsgListMutex; // mutex for above
+    std::mutex                      fQueuedMsgListMutex; // mutex for above
     bool                            fQueuedMsgOn;       // Turns on or off Queued Messages, Plugins need them off
 
     hsKeyedObject*                  IGetOwner() { return fOwner; }
diff --git a/Sources/Plasma/NucleusLib/pnNetCli/pnNcChannel.cpp b/Sources/Plasma/NucleusLib/pnNetCli/pnNcChannel.cpp
index 027310f7..91d5fdf6 100644
--- a/Sources/Plasma/NucleusLib/pnNetCli/pnNcChannel.cpp
+++ b/Sources/Plasma/NucleusLib/pnNetCli/pnNcChannel.cpp
@@ -46,8 +46,8 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 ***/
 
 #include "Pch.h"
-#include "hsThread.h"
 #include <list>
+#include <mutex>
 #include "hsRefCnt.h"
 #pragma hdrstop
 
@@ -61,16 +61,24 @@ namespace pnNetCli {
 ***/
 
 struct ChannelCrit {
-    ~ChannelCrit ();
-    ChannelCrit ();
-    inline void Enter ()        { m_critsect.Lock();               }
-    inline void Leave ()        { m_critsect.Unlock();             }
-    inline void EnterSafe ()    { if (m_init) m_critsect.Lock();   }
-    inline void LeaveSafe ()    { if (m_init) m_critsect.Unlock(); }
+    ~ChannelCrit();
+    ChannelCrit() : m_init(true) { }
+
+    inline void lock()
+    {
+        hsAssert(m_init, "Bad things have happened.");
+        m_critsect.lock();
+    }
+
+    inline void unlock()
+    {
+        hsAssert(m_init, "Bad things have happened.");
+        m_critsect.unlock();
+    }
 
 private:
     bool        m_init;
-    hsMutex     m_critsect;
+    std::mutex  m_critsect;
 };
 
 struct NetMsgChannel : hsRefCnt {
@@ -100,14 +108,10 @@ static std::list<NetMsgChannel*>*   s_channels;
 *
 ***/
 
-//===========================================================================
-ChannelCrit::ChannelCrit () {
-    m_init = true;
-}
-
 //===========================================================================
 ChannelCrit::~ChannelCrit () {
-    EnterSafe();
+    std::lock_guard<ChannelCrit> lock(*this);
+
     if (s_channels) {
         while (s_channels->size()) {
             NetMsgChannel* const channel = s_channels->front();
@@ -118,7 +122,6 @@ ChannelCrit::~ChannelCrit () {
         delete s_channels;
         s_channels = nil;
     }
-    LeaveSafe();
 }
 
 
@@ -298,15 +301,14 @@ NetMsgChannel * NetMsgChannelLock (
     uint32_t *      largestRecv
 ) {
     NetMsgChannel * channel;
-    s_channelCrit.Enter();
-    if (nil != (channel = FindChannel_CS(protocol, server))) {
+    std::lock_guard<ChannelCrit> lock(s_channelCrit);
+    if (nullptr != (channel = FindChannel_CS(protocol, server))) {
         *largestRecv = channel->m_largestRecv;
         channel->Ref("ChannelLock");
     }
     else {
         *largestRecv = 0;
     }
-    s_channelCrit.Leave();
     return channel;
 }
 
@@ -314,11 +316,9 @@ NetMsgChannel * NetMsgChannelLock (
 void NetMsgChannelUnlock (
     NetMsgChannel * channel
 ) {
-    s_channelCrit.Enter();
-    {
-        channel->UnRef("ChannelLock");
-    }
-    s_channelCrit.Leave();
+    std::lock_guard<ChannelCrit> lock(s_channelCrit);
+
+    channel->UnRef("ChannelLock");
 }
 
 //============================================================================
@@ -388,33 +388,31 @@ void NetMsgProtocolRegister (
     const plBigNum&         dh_xa,    // client: dh_x     server: dh_a
     const plBigNum&         dh_n
 ) {
-    s_channelCrit.EnterSafe();
-    {
-        NetMsgChannel * channel = FindOrCreateChannel_CS(protocol, server);
+    std::lock_guard<ChannelCrit> lock(s_channelCrit);
 
-        // make sure no connections have been established on this protocol, otherwise
-        // we'll be modifying a live data structure; NetCli's don't lock their protocol
-        // to operate on it once they have linked to it!
-        ASSERT(channel->RefCnt() == 1);
+    NetMsgChannel * channel = FindOrCreateChannel_CS(protocol, server);
 
-        channel->m_dh_g     = dh_g;
-        channel->m_dh_xa    = dh_xa;
-        channel->m_dh_n     = dh_n;
+    // make sure no connections have been established on this protocol, otherwise
+    // we'll be modifying a live data structure; NetCli's don't lock their protocol
+    // to operate on it once they have linked to it!
+    ASSERT(channel->RefCnt() == 1);
 
-        if (sendMsgCount)
-            AddSendMsgs_CS(channel, sendMsgs, sendMsgCount);
-        if (recvMsgCount)
-            AddRecvMsgs_CS(channel, recvMsgs, recvMsgCount);
-    }
-    s_channelCrit.LeaveSafe();
+    channel->m_dh_g     = dh_g;
+    channel->m_dh_xa    = dh_xa;
+    channel->m_dh_n     = dh_n;
+
+    if (sendMsgCount)
+        AddSendMsgs_CS(channel, sendMsgs, sendMsgCount);
+    if (recvMsgCount)
+        AddRecvMsgs_CS(channel, recvMsgs, recvMsgCount);
 }
 
 //===========================================================================
 void NetMsgProtocolDestroy (uint32_t protocol, bool server) {
-    s_channelCrit.EnterSafe();
+    std::lock_guard<ChannelCrit> lock(s_channelCrit);
+
     if (NetMsgChannel* channel = FindChannel_CS(protocol, server)) {
         s_channels->remove(channel);
         channel->UnRef("ChannelLink");
     }
-    s_channelCrit.LeaveSafe();
 }
diff --git a/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.cpp b/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.cpp
index 4a6c24cb..cb3fdac0 100644
--- a/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.cpp
+++ b/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.cpp
@@ -90,12 +90,13 @@ hsError plSoundPreloader::Run()
 
     while (fRunning)
     {
-        fCritSect.Lock();
-        while (fBuffers.GetCount())
         {
-            templist.Append(fBuffers.Pop());
+            std::lock_guard<std::mutex> lock(fCritSect);
+            while (fBuffers.GetCount())
+            {
+                templist.Append(fBuffers.Pop());
+            }
         }
-        fCritSect.Unlock();
 
         if (templist.GetCount() == 0)
         {
@@ -130,14 +131,15 @@ hsError plSoundPreloader::Run()
     }
 
     // we need to be sure that all buffers are removed from our load list when shutting this thread down or we will hang,
-    // since the sound buffer will wait to be destroyed until it is marked as loaded 
-    fCritSect.Lock();
-    while (fBuffers.GetCount())
+    // since the sound buffer will wait to be destroyed until it is marked as loaded
     {
-        plSoundBuffer* buf = fBuffers.Pop();
-        buf->SetLoaded(true);
+        std::lock_guard<std::mutex> lock(fCritSect);
+        while (fBuffers.GetCount())
+        {
+            plSoundBuffer* buf = fBuffers.Pop();
+            buf->SetLoaded(true);
+        }
     }
-    fCritSect.Unlock();
 
     return hsOK;
 }
diff --git a/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.h b/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.h
index 44cea75f..32ef586d 100644
--- a/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.h
+++ b/Sources/Plasma/PubUtilLib/plAudioCore/plSoundBuffer.h
@@ -57,6 +57,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #include "plAudioFileReader.h"
 #include "hsThread.h"
 #include "plFileSystem.h"
+#include <mutex>
 
 //// Class Definition ////////////////////////////////////////////////////////
 
@@ -165,7 +166,7 @@ protected:
     hsTArray<plSoundBuffer*> fBuffers;
     hsEvent fEvent;
     bool fRunning;
-    hsMutex fCritSect;
+    std::mutex fCritSect;
 
 public:
     virtual hsError Run();
@@ -184,9 +185,10 @@ public:
     bool IsRunning() const { return fRunning; }
 
     void AddBuffer(plSoundBuffer* buffer) {
-        fCritSect.Lock();
-        fBuffers.Push(buffer);
-        fCritSect.Unlock();
+        {
+            std::lock_guard<std::mutex> lock(fCritSect);
+            fBuffers.Push(buffer);
+        }
 
         fEvent.Signal();
     }
diff --git a/Sources/Plasma/PubUtilLib/plFile/plStreamSource.cpp b/Sources/Plasma/PubUtilLib/plFile/plStreamSource.cpp
index cba9a979..d26ee3cf 100644
--- a/Sources/Plasma/PubUtilLib/plFile/plStreamSource.cpp
+++ b/Sources/Plasma/PubUtilLib/plFile/plStreamSource.cpp
@@ -56,7 +56,7 @@ plStreamSource::plStreamSource()
 
 void plStreamSource::ICleanup()
 {
-    hsTempMutexLock lock(fMutex);
+    std::lock_guard<std::mutex> lock(fMutex);
 
     // loop through all the file data records, and delete the streams
     decltype(fFileData.begin()) curData;
@@ -72,7 +72,7 @@ void plStreamSource::ICleanup()
 
 hsStream* plStreamSource::GetFile(const plFileName& filename)
 {
-    hsTempMutexLock lock(fMutex);
+    std::lock_guard<std::mutex> lock(fMutex);
 
     plFileName sFilename = filename.Normalize('/');
     if (fFileData.find(sFilename) == fFileData.end())
@@ -112,7 +112,7 @@ std::vector<plFileName> plStreamSource::GetListOfNames(const plFileName& dir, co
 {
     plFileName sDir = dir.Normalize('/');
     hsAssert(ext.CharAt(0) != '.', "Don't add a dot");
-    hsTempMutexLock lock(fMutex);
+    std::lock_guard<std::mutex> lock(fMutex);
 
     // loop through all the file data records, and create the list
     std::vector<plFileName> retVal;
@@ -142,7 +142,7 @@ bool plStreamSource::InsertFile(const plFileName& filename, hsStream* stream)
 {
     plFileName sFilename = filename.Normalize('/');
 
-    hsTempMutexLock lock(fMutex);
+    std::lock_guard<std::mutex> lock(fMutex);
     if (fFileData.find(sFilename) != fFileData.end())
         return false; // duplicate entry, return failure
 
diff --git a/Sources/Plasma/PubUtilLib/plFile/plStreamSource.h b/Sources/Plasma/PubUtilLib/plFile/plStreamSource.h
index f9b3908c..c5a32563 100644
--- a/Sources/Plasma/PubUtilLib/plFile/plStreamSource.h
+++ b/Sources/Plasma/PubUtilLib/plFile/plStreamSource.h
@@ -43,8 +43,8 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #define plStreamSource_h_inc
 
 #include <map>
+#include <mutex>
 #include "hsStream.h"
-#include "hsThread.h"
 
 // A class for holding and accessing file streams. The preloader will insert
 // files in here once they are loaded. In internal builds, if a requested file
@@ -60,7 +60,7 @@ private:
         hsStream*       fStream; // we own this pointer, so clean it up
     };
     std::map<plFileName, fileData, plFileName::less_i> fFileData; // key is filename
-    hsMutex fMutex;
+    std::mutex fMutex;
     uint32_t fServerKey[4];
 
     void ICleanup(); // closes all file pointers and cleans up after itself
diff --git a/Sources/Plasma/PubUtilLib/plMath/plAvg.cpp b/Sources/Plasma/PubUtilLib/plMath/plAvg.cpp
index 58baceeb..cefae7fd 100644
--- a/Sources/Plasma/PubUtilLib/plMath/plAvg.cpp
+++ b/Sources/Plasma/PubUtilLib/plMath/plAvg.cpp
@@ -55,7 +55,7 @@ const float TimeBasedAvgRing<T>::kPercision = 0.001;
 template <class T>
 void TimeBasedAvgRing<T>::AddItem(T value, double time)
 {
-    hsTempMutexLock lock( fLock );
+    std::lock_guard<std::mutex> lock(fLock);
 
     if ( fList.empty() )
     {
diff --git a/Sources/Plasma/PubUtilLib/plMath/plAvg.h b/Sources/Plasma/PubUtilLib/plMath/plAvg.h
index 80721d3d..e4994cf1 100644
--- a/Sources/Plasma/PubUtilLib/plMath/plAvg.h
+++ b/Sources/Plasma/PubUtilLib/plMath/plAvg.h
@@ -44,9 +44,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 
 #include "HeadSpin.h"
 #include <list>
-
-#include "hsThread.h"
-
+#include <mutex>
 
 // A Time based Value Averaging class
 //  implemented in a ring buffer
@@ -91,7 +89,7 @@ private:
     float fMaxAvg;
     double fTotal;
     TimeListIterator fRingStart, fRingEnd;
-    hsMutex fLock;
+    std::mutex fLock;
 public:
     TimeBasedAvgRing():fLen(0.f),fAvg(0.f),fMaxAvg(0.f),fTotal(0.0) {}
 
diff --git a/Sources/Plasma/PubUtilLib/plStatusLog/plStatusLog.h b/Sources/Plasma/PubUtilLib/plStatusLog/plStatusLog.h
index ef8635ba..65fe3484 100644
--- a/Sources/Plasma/PubUtilLib/plStatusLog/plStatusLog.h
+++ b/Sources/Plasma/PubUtilLib/plStatusLog/plStatusLog.h
@@ -69,7 +69,6 @@ class plPipeline;
 //  really be visible at any given time.
 
 class plStatusLogMgr;
-class hsMutex;
 class plStatusLogDrawerStub;
 class plStatusLog
 {
@@ -206,8 +205,6 @@ class plStatusLogMgr
 
         static plFileName IGetBasePath();
 
-        hsMutex     fMutex;     // To make multithreaded-safe
-
     public:
 
         enum