diff --git a/binaries/data/mods/public/gui/lobby/lobby.js b/binaries/data/mods/public/gui/lobby/lobby.js
index d857f94926..654e44a859 100644
--- a/binaries/data/mods/public/gui/lobby/lobby.js
+++ b/binaries/data/mods/public/gui/lobby/lobby.js
@@ -35,7 +35,7 @@ const g_GameColors = {
 	"init": "0 219 0",
 	"waiting": "255 127 0",
 	"running": "219 0 0"
-}
+};
 
 /**
  * The playerlist will be assembled using these values.
@@ -91,6 +91,81 @@ var g_SelectedPlayer = "";
  */
 var g_SelectedGameIP = "";
 
+/**
+ * Notifications sent by XmppClient.cpp
+ */
+var g_NetMessageTypes = {
+	"system": {
+		// Three cases are handled in prelobby.js
+		"registered": msg => {
+		},
+		"login-failed": msg => {
+		},
+		"connected": msg => {
+		},
+		"disconnected": msg => {
+			updateGameList();
+			updateLeaderboard();
+			updatePlayerList();
+			Engine.GetGUIObjectByName("hostButton").enabled = false;
+			addChatMessage({ "from": "system", "text": translate("Disconnected."), "color": g_SystemColor });
+		},
+		"error": msg => {
+			addChatMessage({ "from": "system", "text": escapeText(msg.text), "color": g_SystemColor });
+		}
+	},
+	"chat": {
+		"subject": msg => {
+			updateSubject(msg.text);
+		},
+		"join": msg => {
+			addChatMessage({
+				"text": "/special " + sprintf(translate("%(nick)s has joined."), { "nick": msg.text }),
+				"isSpecial": true
+			});
+			Engine.SendGetRatingList();
+		},
+		"leave": msg => {
+			addChatMessage({
+				"text": "/special " + sprintf(translate("%(nick)s has left."), { "nick": msg.text }),
+				"isSpecial": true
+			});
+		},
+		"presence": msg => {
+		},
+		"nick": msg => {
+			addChatMessage({
+				"text": "/special " + sprintf(translate("%(oldnick)s is now known as %(newnick)s."), {
+					"oldnick": msg.text,
+					"newnick": msg.data
+				}),
+				"isSpecial": true
+			});
+		},
+		"room-message": msg => {
+			addChatMessage({
+				"from": escapeText(msg.from),
+				"text": escapeText(msg.text),
+				"datetime": msg.datetime
+			});
+		},
+		"private-message": msg => {
+			if (Engine.LobbyGetPlayerRole(msg.from) == "moderator")
+				addChatMessage({
+					"from": "(Private) " + escapeText(msg.from), // TODO: placeholder
+					"text": escapeText(msg.text.trim()), // some XMPP clients send trailing whitespace
+					"datetime": msg.datetime
+				});
+		}
+	},
+	"game": {
+		"gamelist": msg => updateGameList(),
+		"profile": msg => updateProfile(),
+		"leaderboard": msg => updateLeaderboard(),
+		"ratinglist": msg => updatePlayerList()
+	}
+};
+
 /**
  * Called after the XmppConnection succeeded and when returning from a game.
  *
@@ -276,7 +351,7 @@ function updatePlayerList()
 	playersBox.list_status = presenceList;
 	playersBox.list_rating = ratingList;
 	playersBox.list = nickList;
-	playersBox.selected = playersBox.list.indexOf(g_SelectedPlayer)
+	playersBox.selected = playersBox.list.indexOf(g_SelectedPlayer);
 }
 
 /**
@@ -566,80 +641,25 @@ function onTick()
 
 	while (true)
 	{
-		var message = Engine.LobbyGuiPollMessage();
-		if (!message)
+		let msg = Engine.LobbyGuiPollMessage();
+		if (!msg)
 			break;
-		switch (message.type)
+
+		if (!g_NetMessageTypes[msg.type])
 		{
-		case "mucmessage":
-			addChatMessage({ "from": escapeText(message.from), "text": escapeText(message.text), "datetime": message.datetime});
-			break;
-		case "muc":
-			switch(message.level)
-			{
-			case "join":
-				addChatMessage({ "text": "/special " + sprintf(translate("%(nick)s has joined."), { "nick": message.text }), "isSpecial": true });
-				Engine.SendGetRatingList();
-				break;
-			case "leave":
-				addChatMessage({ "text": "/special " + sprintf(translate("%(nick)s has left."), { "nick": message.text }), "isSpecial": true });
-				break;
-			case "nick":
-				addChatMessage({ "text": "/special " + sprintf(translate("%(oldnick)s is now known as %(newnick)s."), { "oldnick": message.text, "newnick": message.data }), "isSpecial": true });
-				break;
-			case "presence":
-				break;
-			case "subject":
-				updateSubject(message.text);
-				break;
-			default:
-				warn(sprintf("Unknown message.level '%(msglvl)s'", { "msglvl": message.level }));
-				break;
-			}
-			// To improve performance, only update the playerlist GUI when the last update in the current stack is processed
-			if (Engine.LobbyGetMucMessageCount() == 0)
-				updatePlayerList();
-			break;
-		case "system":
-			switch (message.level)
-			{
-			case "standard":
-				addChatMessage({ "from": "system", "text": escapeText(message.text), "color": g_SystemColor });
-				if (message.text == "disconnected")
-				{
-					updateGameList();
-					updateLeaderboard();
-					updatePlayerList();
-					Engine.GetGUIObjectByName("hostButton").enabled = false;
-				}
-				else if (message.text == "connected")
-					Engine.GetGUIObjectByName("hostButton").enabled = true;
-				break;
-			case "error":
-				addChatMessage({ "from": "system", "text": escapeText(message.text), "color": g_SystemColor });
-				break;
-			case "internal":
-				switch (message.text)
-				{
-				case "gamelist updated":
-					updateGameList();
-					break;
-				case "boardlist updated":
-					updateLeaderboard();
-					break;
-				case "ratinglist updated":
-					updatePlayerList();
-					break;
-				case "profile updated":
-					updateProfile();
-					break;
-				}
-				break;
-			}
-			break;
-		default:
-			error(sprintf("Unrecognised message type %(msgtype)s", { "msgtype": message.type }));
+			warn("Unrecognised message type: " + msg.type);
+			continue;
 		}
+		if (!g_NetMessageTypes[msg.type][msg.level])
+		{
+			warn("Unrecognised message level: " + msg.level);
+			continue;
+		}
+		g_NetMessageTypes[msg.type][msg.level](msg);
+
+		// To improve performance, only update the playerlist GUI when the last update in the current stack is processed
+		if (msg.type == "chat" && Engine.LobbyGetMucMessageCount() == 0)
+			updatePlayerList();
 	}
 }
 
@@ -888,7 +908,7 @@ function isSpam(text, from)
  */
 function checkSpamMonitor()
 {
-	var time = Math.floor(Date.now() / 1000)
+	var time = Math.floor(Date.now() / 1000);
 	for (let i in g_SpamMonitor)
 	{
 		let stats = g_SpamMonitor[i];
diff --git a/binaries/data/mods/public/gui/lobby/prelobby.js b/binaries/data/mods/public/gui/lobby/prelobby.js
index ba053f3668..45ee322ab1 100644
--- a/binaries/data/mods/public/gui/lobby/prelobby.js
+++ b/binaries/data/mods/public/gui/lobby/prelobby.js
@@ -5,6 +5,39 @@ var g_TermsOfServiceRead = false;
 var g_TermsOfUseRead = false;
 var g_HasSystemMessage = false;
 
+/**
+ * Notifications sent by XmppClient.cpp
+ * Other types are handled in lobby.js
+ */
+var g_SystemMessageTypes = {
+	"error": (message, username, password) => {
+		Engine.GetGUIObjectByName("feedback").caption = message.text;
+		Engine.StopXmppClient();
+	},
+	"login-failed": (message, username, password) => {
+		Engine.GetGUIObjectByName("feedback").caption = translate("Authentication failed");
+		Engine.StopXmppClient();
+	},
+	"registered": (message, username, password) => {
+		Engine.GetGUIObjectByName("feedback").caption = translate("Registered");
+		Engine.GetGUIObjectByName("connectUsername").caption = username;
+		Engine.GetGUIObjectByName("connectPassword").caption = password;
+		Engine.StopXmppClient();
+		switchPage("connect");
+	},
+	"connected": (message, username, password) => {
+		Engine.PopGuiPage();
+		Engine.SwitchGuiPage("page_lobby.xml");
+		
+		Engine.ConfigDB_CreateValue("user", "playername", sanitizePlayerName(username, true, true));
+		Engine.ConfigDB_CreateValue("user", "lobby.login", username);
+		if (password != g_EncrytedPassword.substring(0, 10))
+			g_EncrytedPassword = Engine.EncryptPassword(password, username);
+		Engine.ConfigDB_CreateValue("user", "lobby.password", g_EncrytedPassword);
+		Engine.ConfigDB_WriteFile("user", "config/user.cfg");
+	}
+};
+
 function init()
 {
 	g_EncrytedPassword = Engine.ConfigDB_GetValue("user", "lobby.password");
@@ -69,21 +102,13 @@ function lobbyStartRegister()
 function onTick()
 {
 	var pageRegisterHidden = Engine.GetGUIObjectByName("pageRegister").hidden;
-	if (pageRegisterHidden)
-	{
-		var username = Engine.GetGUIObjectByName("connectUsername").caption;
-		var password = Engine.GetGUIObjectByName("connectPassword").caption;
-	}
-	else
-	{
-		var username = Engine.GetGUIObjectByName("registerUsername").caption;
-		var password = Engine.GetGUIObjectByName("registerPassword").caption;
-	}
+	var username = Engine.GetGUIObjectByName(pageRegisterHidden ? "connectUsername" : "registerUsername").caption;
+	var password = Engine.GetGUIObjectByName(pageRegisterHidden ? "connectPassword" : "registerPassword").caption;
 	var passwordAgain = Engine.GetGUIObjectByName("registerPasswordAgain").caption;
+
 	var agreeTerms = Engine.GetGUIObjectByName("registerAgreeTerms");
 	var feedback = Engine.GetGUIObjectByName("feedback");
 	var continueButton = Engine.GetGUIObjectByName("continue");
-	var sanitizedName = sanitizePlayerName(username, true, true);
 
 	// Do not change feedback while connecting.
 	if (g_LobbyIsConnecting) {}
@@ -99,7 +124,7 @@ function onTick()
 		feedback.caption = translate("Please enter your username");
 	}
 	// Check that they are using a valid username.
-	else if (username != sanitizedName)
+	else if (username != sanitizePlayerName(username, true, true))
 	{
 		continueButton.enabled = false;
 		feedback.caption = translate("Usernames can't contain \\[, ], unicode, whitespace, or commas");
@@ -161,49 +186,20 @@ function onTick()
 
 	// The XmppClient has been created, we are waiting
 	// to be connected or to receive an error.
-
-	//Receive messages
 	while (true)
 	{
-		var message = Engine.LobbyGuiPollMessage();
+		let message = Engine.LobbyGuiPollMessage();
 		if (!message)
 			break;
 
-		if (message.type == "system" && message.text == "connected")
-		{
-			// We are connected, switch to the lobby page
-			Engine.PopGuiPage();
-			// Use username as nick.
-			var nick = sanitizePlayerName(username, true, true);
+		if (message.type != "system")
+			continue;
 
-			// Switch to lobby
-			Engine.SwitchGuiPage("page_lobby.xml");
-			// Store nick, login, and password
-			Engine.ConfigDB_CreateValue("user", "playername", nick);
-			Engine.ConfigDB_CreateValue("user", "lobby.login", username);
-			// We only store the encrypted password, so make sure to re-encrypt it if changed before saving.
-			if (password != g_EncrytedPassword.substring(0, 10))
-				g_EncrytedPassword = Engine.EncryptPassword(password, username);
-			Engine.ConfigDB_CreateValue("user", "lobby.password", g_EncrytedPassword);
-			Engine.ConfigDB_WriteFile("user", "config/user.cfg");
-		}
-		else if (message.type == "system" && message.text == "registered")
-		{
-			// Great, we are registered. Switch to the connection window.
-			feedback.caption = translate("Registered");
-			Engine.StopXmppClient();
-			g_LobbyIsConnecting = false;
-			Engine.GetGUIObjectByName("connectUsername").caption = username;
-			Engine.GetGUIObjectByName("connectPassword").caption = password;
-			switchPage("connect");
-		}
-		else if(message.type == "system" && (message.level == "error" || message.text == "disconnected"))
-		{
-			g_HasSystemMessage = true;
-			feedback.caption = message.text == "disconnected" ? translate("Disconnected") : message.text;
-			Engine.StopXmppClient();
-			g_LobbyIsConnecting = false;
-		}
+		g_HasSystemMessage = true;
+		g_LobbyIsConnecting = false;
+
+		if (g_SystemMessageTypes[message.level])
+			g_SystemMessageTypes[message.level](message, username, password);
 	}
 }
 
diff --git a/source/lobby/XmppClient.cpp b/source/lobby/XmppClient.cpp
index 0a7965b60a..f0f65ecf42 100644
--- a/source/lobby/XmppClient.cpp
+++ b/source/lobby/XmppClient.cpp
@@ -189,7 +189,7 @@ void XmppClient::onConnect()
 {
 	if (m_mucRoom)
 	{
-		CreateSimpleMessage("system", "connected");
+		CreateGUIMessage("system", "connected");
 		m_mucRoom->join();
 	}
 
@@ -220,9 +220,9 @@ void XmppClient::onDisconnect(gloox::ConnectionError error)
 	m_Profile.clear();
 
 	if (error == gloox::ConnAuthenticationFailed)
-		CreateSimpleMessage("system", g_L10n.Translate("Authentication failed"), "error");
+		CreateGUIMessage("system", "login-failed");
 	else
-		CreateSimpleMessage("system", "disconnected");
+		CreateGUIMessage("system", "disconnected");
 }
 
 /**
@@ -249,7 +249,7 @@ bool XmppClient::onTLSConnect(const glooxwrapper::CertInfo& info)
 void XmppClient::handleMUCError(glooxwrapper::MUCRoom*, gloox::StanzaError err)
 {
 	std::string msg = StanzaErrorToString(err);
-	CreateSimpleMessage("system", msg, "error");
+	CreateGUIMessage("system", "error", msg);
 }
 
 /*****************************************************
@@ -445,9 +445,7 @@ void XmppClient::handleRegistrationFields(const glooxwrapper::JID&, int fields,
 void XmppClient::handleRegistrationResult(const glooxwrapper::JID&, gloox::RegistrationResult result)
 {
 	if (result == gloox::RegistrationSuccess)
-	{
-		CreateSimpleMessage("system", "registered");
-	}
+		CreateGUIMessage("system", "registered");
 	else
 	{
 		std::string msg;
@@ -465,7 +463,7 @@ void XmppClient::handleRegistrationResult(const glooxwrapper::JID&, gloox::Regis
 		default: msg = g_L10n.Translate("Registration unknown error");
 		}
 #undef CASE
-		CreateSimpleMessage("system", msg, "error");
+		CreateGUIMessage("system", "error", msg);
 	}
 	disconnect();
 }
@@ -613,8 +611,6 @@ void XmppClient::GuiPollMessage(ScriptInterface& scriptInterface, JS::MutableHan
 		scriptInterface.SetProperty(ret, "text", message.text);
 	if (!message.level.empty())
 		scriptInterface.SetProperty(ret, "level", message.level);
-	if (!message.message.empty())
-		scriptInterface.SetProperty(ret, "message", message.message);
 	if (!message.data.empty())
 		scriptInterface.SetProperty(ret, "data", message.data);
 	if (!message.datetime.empty())
@@ -651,7 +647,7 @@ void XmppClient::ClearPresenceUpdates()
 		std::remove_if(m_GuiMessageQueue.begin(), m_GuiMessageQueue.end(),
 			[](XmppClient::GUIMessage& message)
 			{
-				return message.type == L"muc" && message.level == L"presence";
+				return message.type == L"chat" && message.level == L"presence";
 			}
 	), m_GuiMessageQueue.end());
 }
@@ -664,19 +660,20 @@ int XmppClient::GetMucMessageCount()
 	return std::count_if(m_GuiMessageQueue.begin(), m_GuiMessageQueue.end(),
 		[](XmppClient::GUIMessage& message)
 		{
-			return message.type == L"muc";
+			return message.type == L"chat";
 		});
 }
 
 /**
- * Handle a standard MUC textual message.
+ * Handle a room message.
  */
 void XmppClient::handleMUCMessage(glooxwrapper::MUCRoom*, const glooxwrapper::Message& msg, bool)
 {
 	DbgXMPP(msg.from().resource() << " said " << msg.body());
 
 	GUIMessage message;
-	message.type = L"mucmessage";
+	message.type = L"chat";
+	message.level = L"room-message";
 	message.from = wstring_from_utf8(msg.from().resource().to_string());
 	message.text = wstring_from_utf8(msg.body().to_string());
 	if (msg.when())
@@ -686,7 +683,7 @@ void XmppClient::handleMUCMessage(glooxwrapper::MUCRoom*, const glooxwrapper::Me
 }
 
 /**
- * Handle a standard textual message.
+ * Handle a private message.
  */
 void XmppClient::handleMessage(const glooxwrapper::Message& msg, glooxwrapper::MessageSession *)
 {
@@ -694,8 +691,10 @@ void XmppClient::handleMessage(const glooxwrapper::Message& msg, glooxwrapper::M
 	  << ", message " << msg.body() << ", thread id " << msg.thread());
 
 	GUIMessage message;
+	message.type = L"chat";
+	message.level = L"private-message";
 	message.from = wstring_from_utf8(msg.from().username().to_string());
-	message.message = wstring_from_utf8(msg.body().to_string());
+	message.text = wstring_from_utf8(msg.body().to_string());
 	if (msg.when())
 		//See http://xmpp.org/extensions/xep-0082.html#sect-idp285136 for format
 		message.datetime = msg.when()->stamp().to_string();
@@ -723,7 +722,7 @@ bool XmppClient::handleIq(const glooxwrapper::IQ& iq)
 			for (const glooxwrapper::Tag* const& t : gq->m_GameList)
 				m_GameList.emplace_back(t->clone());
 
-			CreateSimpleMessage("system", "gamelist updated", "internal");
+			CreateGUIMessage("game", "gamelist");
 		}
 		if (bq)
 		{
@@ -736,7 +735,7 @@ bool XmppClient::handleIq(const glooxwrapper::IQ& iq)
 				for (const glooxwrapper::Tag* const& t : bq->m_StanzaBoardList)
 					m_BoardList.emplace_back(t->clone());
 
-				CreateSimpleMessage("system", "boardlist updated", "internal");
+				CreateGUIMessage("game", "leaderboard");
 			}
 			else if (bq->m_Command == "ratinglist")
 			{
@@ -747,7 +746,7 @@ bool XmppClient::handleIq(const glooxwrapper::IQ& iq)
 						m_PlayerMap[name][1] = t->findAttribute("rating").to_string();
 				}
 
-				CreateSimpleMessage("system", "ratinglist updated", "internal");
+				CreateGUIMessage("game", "ratinglist");
 			}
 		}
 		if (pq)
@@ -759,22 +758,21 @@ bool XmppClient::handleIq(const glooxwrapper::IQ& iq)
 			for (const glooxwrapper::Tag* const& t : pq->m_StanzaProfile)
 				m_Profile.emplace_back(t->clone());
 
-			CreateSimpleMessage("system", "profile updated", "internal");
+			CreateGUIMessage("game", "profile");
 		}
 	}
 	else if (iq.subtype() == gloox::IQ::Error)
 	{
 		gloox::StanzaError err = iq.error_error();
 		std::string msg = StanzaErrorToString(err);
-		CreateSimpleMessage("system", msg, "error");
+		CreateGUIMessage("system", "error", msg);
 	}
 	else
 	{
-		CreateSimpleMessage("system", g_L10n.Translate("unknown subtype (see logs)"), "error");
+		CreateGUIMessage("system", "error", g_L10n.Translate("unknown subtype (see logs)"));
 		std::string tag = tag_name(iq);
 		LOGMESSAGE("unknown subtype '%s'", tag.c_str());
 	}
-
 	return true;
 }
 
@@ -786,7 +784,7 @@ bool XmppClient::handleIq(const glooxwrapper::IQ& iq)
  * @param text Body of the message
  * @param data Optional field, used for auxiliary data
  */
-void XmppClient::CreateSimpleMessage(const std::string& type, const std::string& text, const std::string& level, const std::string& data)
+void XmppClient::CreateGUIMessage(const std::string& type, const std::string& level, const std::string& text, const std::string& data)
 {
 	GUIMessage message;
 	message.type = wstring_from_utf8(type);
@@ -820,10 +818,10 @@ void XmppClient::handleMUCParticipantPresence(glooxwrapper::MUCRoom*, const gloo
 			m_PlayerMap[newNick].resize(3);
 			m_PlayerMap[newNick][0] = presenceString;
 			m_PlayerMap[newNick][2] = roleString;
-			CreateSimpleMessage("muc", nick, "nick", participant.newNick.to_string());
+			CreateGUIMessage("chat", "nick", nick, participant.newNick.to_string());
 		}
 		else
-			CreateSimpleMessage("muc", nick, "leave");
+			CreateGUIMessage("chat", "leave", nick);
 
 		DbgXMPP(nick << " left the room");
 		m_PlayerMap.erase(nick);
@@ -840,9 +838,9 @@ void XmppClient::handleMUCParticipantPresence(glooxwrapper::MUCRoom*, const gloo
 				m_initialLoadComplete = true;
 		}
 		else if (m_PlayerMap.find(nick) == m_PlayerMap.end())
-			CreateSimpleMessage("muc", nick, "join");
+			CreateGUIMessage("chat", "join", nick);
 		else
-			CreateSimpleMessage("muc", nick, "presence");
+			CreateGUIMessage("chat", "presence", nick);
 
 		DbgXMPP(nick << " is in the room, presence : " << (int)presenceType);
 		m_PlayerMap[nick].resize(3);
@@ -857,7 +855,7 @@ void XmppClient::handleMUCParticipantPresence(glooxwrapper::MUCRoom*, const gloo
 void XmppClient::handleMUCSubject(glooxwrapper::MUCRoom*, const glooxwrapper::string& UNUSED(nick), const glooxwrapper::string& subject)
 {
 	m_Subject = subject.c_str();
-	CreateSimpleMessage("muc", m_Subject, "subject");
+	CreateGUIMessage("chat", "subject", m_Subject);
 }
 
 /**
diff --git a/source/lobby/XmppClient.h b/source/lobby/XmppClient.h
index 72fadf37c8..062350f8eb 100644
--- a/source/lobby/XmppClient.h
+++ b/source/lobby/XmppClient.h
@@ -144,7 +144,7 @@ public:
 	int GetMucMessageCount();
 	protected:
 	void PushGuiMessage(XmppClient::GUIMessage message);
-	void CreateSimpleMessage(const std::string& type, const std::string& text, const std::string& level = "standard", const std::string& data = "");
+	void CreateGUIMessage(const std::string& type, const std::string& level, const std::string& text = "", const std::string& data = "");
 
 private:
 	/// Map of players