diff --git a/cockatrice/src/abstractclient.cpp b/cockatrice/src/abstractclient.cpp
index 6faf6b33..a91ea784 100644
--- a/cockatrice/src/abstractclient.cpp
+++ b/cockatrice/src/abstractclient.cpp
@@ -19,6 +19,7 @@
 #include "get_pb_extension.h"
 #include <google/protobuf/descriptor.h>
 #include "client_metatypes.h"
+#include "featureset.h"
 
 AbstractClient::AbstractClient(QObject *parent)
     : QObject(parent), nextCmdId(0), status(StatusDisconnected)
@@ -45,6 +46,10 @@ AbstractClient::AbstractClient(QObject *parent)
     qRegisterMetaType<ServerInfo_User>("ServerInfo_User");
     qRegisterMetaType<QList<ServerInfo_User> >("QList<ServerInfo_User>");
     qRegisterMetaType<Event_ReplayAdded>("Event_ReplayAdded");
+    qRegisterMetaType<QList<QString> >("missingFeatures");
+
+    FeatureSet features;
+    features.initalizeFeatureList(clientFeatures);
     
     connect(this, SIGNAL(sigQueuePendingCommand(PendingCommand *)), this, SLOT(queuePendingCommand(PendingCommand *)));
 }
diff --git a/cockatrice/src/abstractclient.h b/cockatrice/src/abstractclient.h
index 939066bc..9c7606a2 100644
--- a/cockatrice/src/abstractclient.h
+++ b/cockatrice/src/abstractclient.h
@@ -25,6 +25,7 @@ class Event_NotifyUser;
 class Event_ConnectionClosed;
 class Event_ServerShutdown;
 class Event_ReplayAdded;
+class FeatureSet;
 
 enum ClientStatus {
     StatusDisconnected,
@@ -96,6 +97,8 @@ public:
     static PendingCommand *prepareRoomCommand(const ::google::protobuf::Message &cmd, int roomId);
     static PendingCommand *prepareModeratorCommand(const ::google::protobuf::Message &cmd);
     static PendingCommand *prepareAdminCommand(const ::google::protobuf::Message &cmd);
+
+    QMap<QString, bool> clientFeatures;
 };
 
 #endif
diff --git a/cockatrice/src/client_metatypes.h b/cockatrice/src/client_metatypes.h
index db1c90f7..d0ece007 100644
--- a/cockatrice/src/client_metatypes.h
+++ b/cockatrice/src/client_metatypes.h
@@ -24,6 +24,6 @@ Q_DECLARE_METATYPE(Event_UserMessage)
 Q_DECLARE_METATYPE(ServerInfo_User)
 Q_DECLARE_METATYPE(QList<ServerInfo_User>)
 Q_DECLARE_METATYPE(Event_ReplayAdded)
-
+Q_DECLARE_METATYPE(QList<QString>)
 
 #endif
diff --git a/cockatrice/src/dlg_settings.cpp b/cockatrice/src/dlg_settings.cpp
index 36733d1f..05e748dd 100644
--- a/cockatrice/src/dlg_settings.cpp
+++ b/cockatrice/src/dlg_settings.cpp
@@ -45,6 +45,7 @@ GeneralSettingsPage::GeneralSettingsPage()
 
     picDownloadCheckBox.setChecked(settingsCache->getPicDownload());
     picDownloadHqCheckBox.setChecked(settingsCache->getPicDownloadHq());
+    updateNotificationCheckBox.setChecked(settingsCache->getNotifyAboutUpdates());
 
     pixmapCacheEdit.setMinimum(PIXMAPCACHE_SIZE_MIN);
     // 2047 is the max value to avoid overflowing of QPixmapCache::setCacheLimit(int size)
@@ -64,19 +65,21 @@ GeneralSettingsPage::GeneralSettingsPage()
     connect(&picDownloadHqCheckBox, SIGNAL(stateChanged(int)), settingsCache, SLOT(setPicDownloadHq(int)));
     connect(&pixmapCacheEdit, SIGNAL(valueChanged(int)), settingsCache, SLOT(setPixmapCacheSize(int)));
     connect(&picDownloadHqCheckBox, SIGNAL(clicked(bool)), this, SLOT(setEnabledStatus(bool)));
+    connect(&updateNotificationCheckBox, SIGNAL(stateChanged(int)), settingsCache, SLOT(setNotifyAboutUpdate(int)));
     connect(highQualityURLEdit, SIGNAL(textChanged(QString)), settingsCache, SLOT(setPicUrlHq(QString)));
 
     QGridLayout *personalGrid = new QGridLayout;
     personalGrid->addWidget(&languageLabel, 0, 0);
     personalGrid->addWidget(&languageBox, 0, 1);
-    personalGrid->addWidget(&pixmapCacheLabel, 1, 0, 1, 1);
-    personalGrid->addWidget(&pixmapCacheEdit, 1, 1, 1, 1);
-    personalGrid->addWidget(&picDownloadCheckBox, 2, 0, 1, 2);
-    personalGrid->addWidget(&picDownloadHqCheckBox, 3, 0, 1, 2);
-    personalGrid->addWidget(&clearDownloadedPicsButton, 4, 0, 1, 1);
-    personalGrid->addWidget(&highQualityURLLabel, 5, 0, 1, 1);
-    personalGrid->addWidget(highQualityURLEdit, 5, 1, 1, 1);
-    personalGrid->addWidget(&highQualityURLLinkLabel, 6, 1, 1, 1);
+    personalGrid->addWidget(&pixmapCacheLabel, 1, 0);
+    personalGrid->addWidget(&pixmapCacheEdit, 1, 1);
+    personalGrid->addWidget(&updateNotificationCheckBox, 2, 0);
+    personalGrid->addWidget(&picDownloadCheckBox, 3, 0);
+    personalGrid->addWidget(&picDownloadHqCheckBox, 4, 0);
+    personalGrid->addWidget(&highQualityURLLabel, 5, 0);
+    personalGrid->addWidget(highQualityURLEdit, 5, 1);
+    personalGrid->addWidget(&highQualityURLLinkLabel, 6, 1);
+    personalGrid->addWidget(&clearDownloadedPicsButton, 6, 0);
     
     highQualityURLLinkLabel.setTextInteractionFlags(Qt::LinksAccessibleByMouse);
     highQualityURLLinkLabel.setOpenExternalLinks(true);
@@ -246,6 +249,7 @@ void GeneralSettingsPage::retranslateUi()
     highQualityURLLabel.setText(tr("Custom Card Download URL:"));
     highQualityURLLinkLabel.setText(QString("<a href='%1'>%2</a>").arg(LINKING_FAQ_URL).arg(tr("Linking FAQ")));
     clearDownloadedPicsButton.setText(tr("Reset/Clear Downloaded Pictures"));
+    updateNotificationCheckBox.setText(tr("Notify when new client features are available"));
 }
 
 void GeneralSettingsPage::setEnabledStatus(bool status)
@@ -914,3 +918,4 @@ void DlgSettings::retranslateUi()
     for (int i = 0; i < pagesWidget->count(); i++)
         dynamic_cast<AbstractSettingsPage *>(pagesWidget->widget(i))->retranslateUi();
 }
+
diff --git a/cockatrice/src/dlg_settings.h b/cockatrice/src/dlg_settings.h
index 2bceda71..45443c0b 100644
--- a/cockatrice/src/dlg_settings.h
+++ b/cockatrice/src/dlg_settings.h
@@ -60,6 +60,7 @@ private:
     QComboBox languageBox;
     QCheckBox picDownloadCheckBox;
     QCheckBox picDownloadHqCheckBox;
+    QCheckBox updateNotificationCheckBox;
     QLabel languageLabel;
     QLabel pixmapCacheLabel;
     QLabel deckPathLabel;
diff --git a/cockatrice/src/main.cpp b/cockatrice/src/main.cpp
index b8216163..c6f303b6 100644
--- a/cockatrice/src/main.cpp
+++ b/cockatrice/src/main.cpp
@@ -33,7 +33,6 @@
 #include <QSystemTrayIcon>
 #include "QtNetwork/QNetworkInterface"
 #include <QCryptographicHash>
-
 #include "main.h"
 #include "window_main.h"
 #include "dlg_settings.h"
@@ -43,6 +42,7 @@
 #include "pixmapgenerator.h"
 #include "rng_sfmt.h"
 #include "soundengine.h"
+#include "featureset.h"
 
 //Q_IMPORT_PLUGIN(qjpeg)
 
diff --git a/cockatrice/src/remoteclient.cpp b/cockatrice/src/remoteclient.cpp
index e149082b..b652726d 100644
--- a/cockatrice/src/remoteclient.cpp
+++ b/cockatrice/src/remoteclient.cpp
@@ -1,3 +1,4 @@
+#include <QList>
 #include <QTimer>
 #include <QThread>
 #include "remoteclient.h"
@@ -81,7 +82,6 @@ void RemoteClient::processServerIdentificationEvent(const Event_ServerIdentifica
         cmdRegister.set_country(country.toStdString());
         cmdRegister.set_real_name(realName.toStdString());
         cmdRegister.set_clientid(settingsCache->getClientID().toStdString());
-
         PendingCommand *pend = prepareSessionCommand(cmdRegister);
         connect(pend, SIGNAL(finished(Response, CommandContainer, QVariant)), this, SLOT(registerResponse(Response)));
         sendCommand(pend);
@@ -105,8 +105,7 @@ void RemoteClient::processServerIdentificationEvent(const Event_ServerIdentifica
     doLogin();
 }
 
-void RemoteClient::doLogin()
-{
+void RemoteClient::doLogin() {
     setStatus(StatusLoggingIn);
 
     Command_Login cmdLogin;
@@ -114,6 +113,13 @@ void RemoteClient::doLogin()
     cmdLogin.set_password(password.toStdString());
     cmdLogin.set_clientid(settingsCache->getClientID().toStdString());
     cmdLogin.set_clientver(VERSION_STRING);
+
+    if (!clientFeatures.isEmpty()) {
+        QMap<QString, bool>::iterator i;
+        for (i = clientFeatures.begin(); i != clientFeatures.end(); ++i)
+            cmdLogin.add_clientfeatures(i.key().toStdString().c_str());
+    }
+
     PendingCommand *pend = prepareSessionCommand(cmdLogin);
     connect(pend, SIGNAL(finished(Response, CommandContainer, QVariant)), this, SLOT(loginResponse(Response)));
     sendCommand(pend);
@@ -140,8 +146,17 @@ void RemoteClient::loginResponse(const Response &response)
         for (int i = resp.ignore_list_size() - 1; i >= 0; --i)
             ignoreList.append(resp.ignore_list(i));
         emit ignoreListReceived(ignoreList);
+
+        if (resp.missing_features_size() > 0 && settingsCache->getNotifyAboutUpdates())
+                emit notifyUserAboutUpdate();
+
     } else {
-        emit loginError(response.response_code(), QString::fromStdString(resp.denied_reason_str()), resp.denied_end_time());
+        QList<QString> missingFeatures;
+        if (resp.missing_features_size() > 0) {
+            for (int i = 0; i < resp.missing_features_size(); ++i)
+                missingFeatures << QString::fromStdString(resp.missing_features(i));
+        }
+        emit loginError(response.response_code(), QString::fromStdString(resp.denied_reason_str()), resp.denied_end_time(), missingFeatures);
         setStatus(StatusDisconnecting);
     }
 }
diff --git a/cockatrice/src/remoteclient.h b/cockatrice/src/remoteclient.h
index c1478732..3e0ae971 100644
--- a/cockatrice/src/remoteclient.h
+++ b/cockatrice/src/remoteclient.h
@@ -11,7 +11,7 @@ class RemoteClient : public AbstractClient {
 signals:
     void maxPingTime(int seconds, int maxSeconds);
     void serverTimeout();
-    void loginError(Response::ResponseCode resp, QString reasonStr, quint32 endTime);
+    void loginError(Response::ResponseCode resp, QString reasonStr, quint32 endTime, QList<QString> missingFeatures);
     void registerError(Response::ResponseCode resp, QString reasonStr, quint32 endTime);
     void activateError();
     void socketError(const QString &errorString);
@@ -21,6 +21,7 @@ signals:
     void sigRegisterToServer(const QString &hostname, unsigned int port, const QString &_userName, const QString &_password, const QString &_email, const int _gender, const QString &_country, const QString &_realname);
     void sigActivateToServer(const QString &_token);
     void sigDisconnectFromServer();
+    void notifyUserAboutUpdate();
 private slots:
     void slotConnected();
     void readData();
diff --git a/cockatrice/src/settingscache.cpp b/cockatrice/src/settingscache.cpp
index 131653ad..3a1b7b5c 100644
--- a/cockatrice/src/settingscache.cpp
+++ b/cockatrice/src/settingscache.cpp
@@ -130,6 +130,7 @@ SettingsCache::SettingsCache()
     if(!QFile(settingsPath+"global.ini").exists())
         translateLegacySettings();
 
+    notifyAboutUpdates = settings->value("personal/updatenotification", true).toBool();
     lang = settings->value("personal/lang").toString();
     keepalive = settings->value("personal/keepalive", 5).toInt();
     deckPath = settings->value("paths/decks").toString();
@@ -620,4 +621,10 @@ void SettingsCache::setRememberGameSettings(const bool _rememberGameSettings)
 {
     rememberGameSettings = _rememberGameSettings;
     settings->setValue("game/remembergamesettings", rememberGameSettings);
+}
+
+void SettingsCache::setNotifyAboutUpdate(int _notifyaboutupdate)
+{
+    notifyAboutUpdates = _notifyaboutupdate;
+    settings->setValue("personal/updatenotification", notifyAboutUpdates);
 }
\ No newline at end of file
diff --git a/cockatrice/src/settingscache.h b/cockatrice/src/settingscache.h
index 775a53d4..1cfe4d42 100644
--- a/cockatrice/src/settingscache.h
+++ b/cockatrice/src/settingscache.h
@@ -58,6 +58,7 @@ private:
     QByteArray mainWindowGeometry;
     QString lang;
     QString deckPath, replaysPath, picsPath, cardDatabasePath, tokenDatabasePath, themeName;
+    bool notifyAboutUpdates;
     bool picDownload;
     bool picDownloadHq;
     bool notificationsEnabled;
@@ -129,6 +130,7 @@ public:
     bool getPicDownloadHq() const { return picDownloadHq; }
     bool getNotificationsEnabled() const { return notificationsEnabled; }
     bool getSpectatorNotificationsEnabled() const { return spectatorNotificationsEnabled; }
+    bool getNotifyAboutUpdates() const { return notifyAboutUpdates; }
 
     bool getDoubleClickToPlay() const { return doubleClickToPlay; }
     bool getPlayToStack() const { return playToStack; }
@@ -251,6 +253,7 @@ public slots:
     void setSpectatorsCanTalk(const bool _spectatorsCanTalk);
     void setSpectatorsCanSeeEverything(const bool _spectatorsCanSeeEverything);
     void setRememberGameSettings(const bool _rememberGameSettings);
+    void setNotifyAboutUpdate(int _notifyaboutupdate);
 };
 
 extern SettingsCache *settingsCache;
diff --git a/cockatrice/src/window_main.cpp b/cockatrice/src/window_main.cpp
index 812fc1df..6ff7a56e 100644
--- a/cockatrice/src/window_main.cpp
+++ b/cockatrice/src/window_main.cpp
@@ -30,6 +30,7 @@
 #include <QDateTime>
 #include <QSystemTrayIcon>
 #include <QApplication>
+
 #if QT_VERSION < 0x050000
     #include <QtGui/qtextdocument.h> // for Qt::escape()
 #endif
@@ -293,9 +294,23 @@ void MainWindow::serverTimeout()
     actConnect();
 }
 
-void MainWindow::loginError(Response::ResponseCode r, QString reasonStr, quint32 endTime)
+void MainWindow::loginError(Response::ResponseCode r, QString reasonStr, quint32 endTime, QList<QString> missingFeatures)
 {
     switch (r) {
+        case Response::RespClientUpdateRequired: {
+            QString formatedMissingFeatures;
+            formatedMissingFeatures = "Missing Features: ";
+            for (int i = 0; i < missingFeatures.size(); ++i)
+                formatedMissingFeatures.append(QString("\n     %1").arg(QChar(0x2022)) + " " + missingFeatures.value(i)   );
+
+            QMessageBox msgBox;
+            msgBox.setIcon(QMessageBox::Critical);
+            msgBox.setWindowTitle(tr("Failed Login"));
+            msgBox.setText(tr("Your client does not support features that the server requires, please update your client and try again."));
+            msgBox.setDetailedText(formatedMissingFeatures);
+            msgBox.exec();
+            break;
+        }
         case Response::RespWrongPassword:
             QMessageBox::critical(this, tr("Error"), tr("Incorrect username or password. Please check your authentication information and try again."));
             break;
@@ -561,13 +576,13 @@ MainWindow::MainWindow(QWidget *parent)
     client = new RemoteClient;
     connect(client, SIGNAL(connectionClosedEventReceived(const Event_ConnectionClosed &)), this, SLOT(processConnectionClosedEvent(const Event_ConnectionClosed &)));
     connect(client, SIGNAL(serverShutdownEventReceived(const Event_ServerShutdown &)), this, SLOT(processServerShutdownEvent(const Event_ServerShutdown &)));
-    connect(client, SIGNAL(loginError(Response::ResponseCode, QString, quint32)), this, SLOT(loginError(Response::ResponseCode, QString, quint32)));
+    connect(client, SIGNAL(loginError(Response::ResponseCode, QString, quint32, QList<QString>)), this, SLOT(loginError(Response::ResponseCode, QString, quint32, QList<QString>)));
     connect(client, SIGNAL(socketError(const QString &)), this, SLOT(socketError(const QString &)));
     connect(client, SIGNAL(serverTimeout()), this, SLOT(serverTimeout()));
     connect(client, SIGNAL(statusChanged(ClientStatus)), this, SLOT(statusChanged(ClientStatus)));
     connect(client, SIGNAL(protocolVersionMismatch(int, int)), this, SLOT(protocolVersionMismatch(int, int)));
     connect(client, SIGNAL(userInfoChanged(const ServerInfo_User &)), this, SLOT(userInfoReceived(const ServerInfo_User &)), Qt::BlockingQueuedConnection);
-
+    connect(client, SIGNAL(notifyUserAboutUpdate()), this, SLOT(notifyUserAboutUpdate()));
     connect(client, SIGNAL(registerAccepted()), this, SLOT(registerAccepted()));
     connect(client, SIGNAL(registerAcceptedNeedsActivate()), this, SLOT(registerAcceptedNeedsActivate()));
     connect(client, SIGNAL(registerError(Response::ResponseCode, QString, quint32)), this, SLOT(registerError(Response::ResponseCode, QString, quint32)));
@@ -795,3 +810,8 @@ void MainWindow::refreshShortcuts()
     aExit->setShortcuts(settingsCache->shortcuts().getShortcut("MainWindow/aExit"));
     aCheckCardUpdates->setShortcuts(settingsCache->shortcuts().getShortcut("MainWindow/aCheckCardUpdates"));
 }
+
+void MainWindow::notifyUserAboutUpdate()
+{
+    QMessageBox::information(this, tr("Information"), tr("Your client appears to be missing features that the server supports.\nThis usually means that your client version is out of date,pleae check to see if there is a new client available for download."));
+}
diff --git a/cockatrice/src/window_main.h b/cockatrice/src/window_main.h
index 5a12676e..149f7197 100644
--- a/cockatrice/src/window_main.h
+++ b/cockatrice/src/window_main.h
@@ -20,6 +20,7 @@
 #ifndef WINDOW_H
 #define WINDOW_H
 
+#include <QList>
 #include <QMainWindow>
 #include <QSystemTrayIcon>
 #include <QProcess>
@@ -42,7 +43,7 @@ private slots:
     void processConnectionClosedEvent(const Event_ConnectionClosed &event);
     void processServerShutdownEvent(const Event_ServerShutdown &event);
     void serverTimeout();
-    void loginError(Response::ResponseCode r, QString reasonStr, quint32 endTime);
+    void loginError(Response::ResponseCode r, QString reasonStr, quint32 endTime, QList<QString> missingFeatures);
     void registerError(Response::ResponseCode r, QString reasonStr, quint32 endTime);
     void activateError();
     void socketError(const QString &errorStr);
@@ -53,7 +54,7 @@ private slots:
     void activateAccepted();
     void localGameEnded();
     void pixmapCacheSizeChanged(int newSizeInMBs);
-
+    void notifyUserAboutUpdate();
     void actConnect();
     void actDisconnect();
     void actSinglePlayer();
diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt
index 47dab1f5..d73dc6f8 100644
--- a/common/CMakeLists.txt
+++ b/common/CMakeLists.txt
@@ -7,6 +7,7 @@ add_subdirectory(pb)
 
 SET(common_SOURCES
     decklist.cpp
+    featureset.cpp
     get_pb_extension.cpp
     rng_abstract.cpp
     rng_sfmt.cpp
diff --git a/common/featureset.cpp b/common/featureset.cpp
new file mode 100644
index 00000000..f940a461
--- /dev/null
+++ b/common/featureset.cpp
@@ -0,0 +1,55 @@
+#include "featureset.h"
+#include <QMap>
+#include <QDebug>
+
+FeatureSet::FeatureSet()
+{
+
+}
+
+QMap<QString, bool> FeatureSet::getDefaultFeatureList() {
+    initalizeFeatureList(featureList);
+    return featureList;
+}
+
+void FeatureSet::initalizeFeatureList(QMap<QString, bool> &featureList){
+    featureList.insert("client_id", false);
+    featureList.insert("client_ver", false);
+    featureList.insert("feature_set", false);
+}
+
+void FeatureSet::enableRequiredFeature(QMap<QString, bool> &featureList, QString featureName){
+    if (featureList.contains(featureName))
+        featureList.insert(featureName,true);
+}
+
+void FeatureSet::disableRequiredFeature(QMap<QString, bool> &featureList, QString featureName){
+    if (featureList.contains(featureName))
+        featureList.insert(featureName,false);
+}
+
+QMap<QString, bool> FeatureSet::addFeature(QMap<QString, bool> &featureList, QString featureName, bool isFeatureRequired){
+    featureList.insert(featureName,isFeatureRequired);
+    return featureList;
+}
+
+QMap<QString, bool> FeatureSet::identifyMissingFeatures(QMap<QString, bool> suppliedFeatures, QMap<QString, bool> requiredFeatures){
+    QMap<QString, bool> missingList;
+    QMap<QString, bool>::iterator i;
+    for (i = requiredFeatures.begin(); i != requiredFeatures.end(); ++i) {
+        if (!suppliedFeatures.contains(i.key())) {
+            missingList.insert(i.key(), i.value());
+        }
+    }
+    return missingList;
+}
+
+bool FeatureSet::isRequiredFeaturesMissing(QMap<QString, bool> suppliedFeatures, QMap<QString, bool> requiredFeatures) {
+    QMap<QString, bool>::iterator i;
+    for (i = requiredFeatures.begin(); i != requiredFeatures.end(); ++i) {
+        if (i.value() && suppliedFeatures.contains(i.key())) {
+                return true;
+        }
+    }
+    return false;
+}
diff --git a/common/featureset.h b/common/featureset.h
new file mode 100644
index 00000000..620ba96a
--- /dev/null
+++ b/common/featureset.h
@@ -0,0 +1,24 @@
+#ifndef FEATURESET_H
+#define FEATURESET_H
+
+#include <QMap>
+#include <QSet>
+#include <QString>
+
+class FeatureSet
+{
+public:
+    FeatureSet();
+    QMap<QString, bool> getDefaultFeatureList();
+    void initalizeFeatureList(QMap<QString, bool> &featureList);
+    void enableRequiredFeature(QMap<QString, bool> &featureList, QString featureName);
+    void disableRequiredFeature(QMap<QString, bool> &featureList, QString featureName);
+    QMap<QString, bool> addFeature(QMap<QString, bool> &featureList, QString featureName, bool isFeatureRequired);
+    QMap<QString, bool> identifyMissingFeatures(QMap<QString, bool> featureListToCheck, QMap<QString, bool> featureListToCompareTo);
+    bool isRequiredFeaturesMissing(QMap<QString, bool> featureListToCheck, QMap<QString, bool> featureListToCompareTo);
+private:
+    QMap<QString, bool> featureList;
+};
+
+
+#endif // FEEATURESET_H
diff --git a/common/pb/response.proto b/common/pb/response.proto
index ba3ccc6a..ce2aec00 100644
--- a/common/pb/response.proto
+++ b/common/pb/response.proto
@@ -37,6 +37,7 @@ message Response {
         RespActivationFailed = 32; // Server didn't accept a reg user activation token
         RespRegistrationAcceptedNeedsActivation = 33; // Server accepted cient registration, but it will need token activation
         RespClientIdRequired = 34; // Server requires client to generate and send its client id before allowing access
+        RespClientUpdateRequired = 35; // Client is missing features that the server is requiring
     }
     enum ResponseType {
         JOIN_ROOM = 1000;
diff --git a/common/pb/response_login.proto b/common/pb/response_login.proto
index fecd9d83..673eaa46 100644
--- a/common/pb/response_login.proto
+++ b/common/pb/response_login.proto
@@ -11,4 +11,5 @@ message Response_Login {
     repeated ServerInfo_User ignore_list = 3;
     optional string denied_reason_str = 4;
     optional uint64 denied_end_time = 5;
+    repeated string missing_features = 6;
 }
diff --git a/common/pb/session_commands.proto b/common/pb/session_commands.proto
index 0d5b12bd..afd85a39 100644
--- a/common/pb/session_commands.proto
+++ b/common/pb/session_commands.proto
@@ -46,6 +46,7 @@ message Command_Login {
     optional string password = 2;
     optional string clientid = 3;
     optional string clientver = 4;
+    repeated string clientfeatures = 5;
 }
 
 message Command_Message {
diff --git a/common/server.cpp b/common/server.cpp
index 88d52909..e0a015ec 100644
--- a/common/server.cpp
+++ b/common/server.cpp
@@ -32,6 +32,7 @@
 #include "pb/session_event.pb.h"
 #include "pb/event_connection_closed.pb.h"
 #include "pb/isl_message.pb.h"
+#include "featureset.h"
 #include <QCoreApplication>
 #include <QThread>
 #include <QDebug>
diff --git a/common/server.h b/common/server.h
index 494ec534..e4b635e0 100644
--- a/common/server.h
+++ b/common/server.h
@@ -51,10 +51,10 @@ public:
     Server_AbstractUserInterface *findUser(const QString &userName) const;
     const QMap<QString, Server_ProtocolHandler *> &getUsers() const { return users; }
     const QMap<qint64, Server_ProtocolHandler *> &getUsersBySessionId() const { return usersBySessionId; }
+    virtual QMap<QString, bool> getServerRequiredFeatureList() const { return QMap<QString, bool>(); }
     void addClient(Server_ProtocolHandler *player);
     void removeClient(Server_ProtocolHandler *player);
     virtual QString getLoginMessage() const { return QString(); }
-
     virtual bool permitUnregisteredUsers() const { return true; }
     virtual bool getGameShouldPing() const { return false; }
     virtual bool getClientIdRequired() const { return false; }
@@ -94,6 +94,7 @@ private:
     mutable QReadWriteLock persistentPlayersLock;
     int nextLocalGameId;
     QMutex nextLocalGameIdMutex;
+
 protected slots:
     void externalUserJoined(const ServerInfo_User &userInfo);
     void externalUserLeft(const QString &userName);
diff --git a/common/server_protocolhandler.cpp b/common/server_protocolhandler.cpp
index c4ed0f51..775b204f 100644
--- a/common/server_protocolhandler.cpp
+++ b/common/server_protocolhandler.cpp
@@ -19,6 +19,8 @@
 #include "pb/event_game_joined.pb.h"
 #include "pb/event_room_say.pb.h"
 #include <google/protobuf/descriptor.h>
+#include "featureset.h"
+
 
 Server_ProtocolHandler::Server_ProtocolHandler(Server *_server, Server_DatabaseInterface *_databaseInterface, QObject *parent)
     : QObject(parent),
@@ -382,10 +384,32 @@ Response::ResponseCode Server_ProtocolHandler::cmdLogin(const Command_Login &cmd
 {
     QString userName = QString::fromStdString(cmd.user_name()).simplified();
     QString clientId = QString::fromStdString(cmd.clientid()).simplified();
-    
+
     if (userName.isEmpty() || (userInfo != 0))
         return Response::RespContextError;
 
+    // check client feature set against server feature set
+    FeatureSet features;
+    QMap<QString, bool> receivedClientFeatures;
+    QMap<QString, bool> missingClientFeatures;
+
+    for (int i = 0; i < cmd.clientfeatures().size(); ++i)
+        receivedClientFeatures.insert(QString::fromStdString(cmd.clientfeatures(i)).simplified(), false);
+
+    missingClientFeatures = features.identifyMissingFeatures(receivedClientFeatures, server->getServerRequiredFeatureList());
+
+    if (!missingClientFeatures.isEmpty()) {
+        if (features.isRequiredFeaturesMissing(missingClientFeatures, server->getServerRequiredFeatureList())) {
+            Response_Login *re = new Response_Login;
+            re->set_denied_reason_str("Client upgrade required");
+            QMap<QString, bool>::iterator i;
+            for (i = missingClientFeatures.begin(); i != missingClientFeatures.end(); ++i)
+                re->add_missing_features(i.key().toStdString().c_str());
+            rc.setResponseExtension(re);
+            return Response::RespClientUpdateRequired;
+        }
+    }
+
     QString reasonStr;
     int banSecondsLeft = 0;
     AuthenticationResult res = server->loginUser(this, userName, QString::fromStdString(cmd.password()), reasonStr, banSecondsLeft, clientId);
@@ -430,6 +454,13 @@ Response::ResponseCode Server_ProtocolHandler::cmdLogin(const Command_Login &cmd
             re->add_ignore_list()->CopyFrom(ignoreIterator.next().value());
     }
 
+    // return to client any missing features the server has that the client does not
+    if (!missingClientFeatures.isEmpty()) {
+        QMap<QString, bool>::iterator i;
+        for (i = missingClientFeatures.begin(); i != missingClientFeatures.end(); ++i)
+            re->add_missing_features(i.key().toStdString().c_str());
+    }
+
     joinPersistentGames(rc);
 
     rc.setResponseExtension(re);
diff --git a/common/server_protocolhandler.h b/common/server_protocolhandler.h
index bf9d1940..5c9aef9a 100644
--- a/common/server_protocolhandler.h
+++ b/common/server_protocolhandler.h
@@ -8,11 +8,13 @@
 #include "pb/response.pb.h"
 #include "pb/server_message.pb.h"
 
+class Features;
 class Server_DatabaseInterface;
 class Server_Player;
 class ServerInfo_User;
 class Server_Room;
 class QTimer;
+class FeatureSet;
 
 class ServerMessage;
 class Response;
diff --git a/servatrice/servatrice.ini.example b/servatrice/servatrice.ini.example
index ce57df53..842fb032 100644
--- a/servatrice/servatrice.ini.example
+++ b/servatrice/servatrice.ini.example
@@ -50,6 +50,12 @@ max_player_inactivity_time=15
 ' require that clients report the client ID in order to log into the server.  Default is false
 requireclientid=false
 
+; You can limit the types of clients that connect to the server by requiring different features be available
+; on the client.  This setting can contain a comma-seperated list of features.  if any of the features
+; listed in this line are not available on the client the client will be denied access to the server upon
+; attempting to log in.  Example: "client_id,client_ver"
+requiredfeatures=""
+
 [authentication]
 
 ; Servatrice can authenticate users connecting. It currently supports 3 different authentication methods:
diff --git a/servatrice/src/main.cpp b/servatrice/src/main.cpp
index 499b468d..d19ebb66 100644
--- a/servatrice/src/main.cpp
+++ b/servatrice/src/main.cpp
@@ -198,6 +198,7 @@ int main(int argc, char *argv[])
 #else
 		qInstallMessageHandler(myMessageOutput);
 #endif
+
 		retval = app.exec();
 		
 		std::cerr << "Server quit." << std::endl;
diff --git a/servatrice/src/servatrice.cpp b/servatrice/src/servatrice.cpp
index 701902f8..f1f29191 100644
--- a/servatrice/src/servatrice.cpp
+++ b/servatrice/src/servatrice.cpp
@@ -38,6 +38,7 @@
 #include "pb/event_server_message.pb.h"
 #include "pb/event_server_shutdown.pb.h"
 #include "pb/event_connection_closed.pb.h"
+#include "featureset.h"
 
 Servatrice_GameServer::Servatrice_GameServer(Servatrice *_server, int _numberPools, const QSqlDatabase &_sqlDatabase, QObject *parent)
     : QTcpServer(parent),
@@ -179,6 +180,16 @@ bool Servatrice::initServer()
     if (registrationEnabled)
         qDebug() << "Require email address to register: " << requireEmailForRegistration;
 
+    FeatureSet features;
+    features.initalizeFeatureList(serverRequiredFeatureList);
+    requiredFeatures = settingsCache->value("server/requiredfeatures","").toString();
+    QStringList listReqFeatures = requiredFeatures.split(",", QString::SkipEmptyParts);
+    if (!listReqFeatures.isEmpty())
+        foreach(QString reqFeature, listReqFeatures)
+            features.enableRequiredFeature(serverRequiredFeatureList,reqFeature);
+
+    qDebug() << "Required client features: " << serverRequiredFeatureList;
+
     QString dbTypeStr = settingsCache->value("database/type").toString();
     if (dbTypeStr == "mysql")
         databaseType = DatabaseMySql;
diff --git a/servatrice/src/servatrice.h b/servatrice/src/servatrice.h
index 4e4a74b2..ad42497b 100644
--- a/servatrice/src/servatrice.h
+++ b/servatrice/src/servatrice.h
@@ -30,6 +30,7 @@
 #include <QMetaType>
 #include "server.h"
 
+
 Q_DECLARE_METATYPE(QSqlDatabase)
 
 class QSqlQuery;
@@ -41,6 +42,7 @@ class Servatrice_ConnectionPool;
 class Servatrice_DatabaseInterface;
 class ServerSocketInterface;
 class IslInterface;
+class FeatureSet;
 
 class Servatrice_GameServer : public QTcpServer {
     Q_OBJECT
@@ -109,6 +111,8 @@ private:
     mutable QMutex loginMessageMutex;
     QString loginMessage;
     QString dbPrefix;
+    QString requiredFeatures;
+    QMap<QString, bool> serverRequiredFeatureList;
     Servatrice_DatabaseInterface *servatriceDatabaseInterface;
     int serverId;
     int uptime;
@@ -134,8 +138,10 @@ public:
     Servatrice(QObject *parent = 0);
     ~Servatrice();
     bool initServer();
+    QMap<QString, bool> getServerRequiredFeatureList() const { return serverRequiredFeatureList; }
     QString getServerName() const { return serverName; }
     QString getLoginMessage() const { QMutexLocker locker(&loginMessageMutex); return loginMessage; }
+    QString getRequiredFeatures() const { return requiredFeatures; }
     bool permitUnregisteredUsers() const { return authenticationMethod != AuthenticationNone; }
     bool getGameShouldPing() const { return true; }
     bool getClientIdRequired() const { return clientIdRequired; }