diff --git a/binaries/data/mods/public/gui/gamesetup/gamesetup.js b/binaries/data/mods/public/gui/gamesetup/gamesetup.js
index 8fb3484aa6..15986d95c2 100644
--- a/binaries/data/mods/public/gui/gamesetup/gamesetup.js
+++ b/binaries/data/mods/public/gui/gamesetup/gamesetup.js
@@ -11,8 +11,7 @@ var g_IsController;
 // (and therefore shouldn't send further messages to the network)
 var g_IsInGuiUpdate;
 
-// Default single-player player assignments
-var g_PlayerAssignments = { "local": { "name": "You", "player": 1 } };
+var g_PlayerAssignments = {};
 
 // Default game setup attributes
 var g_GameAttributes = { "map": "Latium" };
@@ -20,6 +19,8 @@ var g_GameAttributes = { "map": "Latium" };
 // Number of players for currently selected map
 var g_MaxPlayers = 8;
 
+var g_ChatMessages = [];
+
 function init(attribs)
 {
 	switch (attribs.type)
@@ -49,20 +50,30 @@ function init(attribs)
 			getGUIObjectByName("playerAssignment["+i+"]").enabled = false;
 	}
 
+	// Set up offline-only bits:
+	if (!g_IsNetworked)
+	{
+		getGUIObjectByName("chatPanel").hidden = true;
+
+		g_PlayerAssignments = { "local": { "name": "You", "player": 1 } };
+	}
+
 	updatePlayerList();
 }
 
+function cancelSetup()
+{
+	Engine.DisconnectNetworkGame();
+}
+
 function onTick()
 {
-	if (g_IsNetworked)
+	while (true)
 	{
-		while (true)
-		{
-			var message = Engine.PollNetworkClient();
-			if (!message)
-				break;
-			handleNetMessage(message);
-		}
+		var message = Engine.PollNetworkClient();
+		if (!message)
+			break;
+		handleNetMessage(message);
 	}
 }
 
@@ -72,6 +83,20 @@ function handleNetMessage(message)
 
 	switch (message.type)
 	{
+	case "netstatus":
+		switch (message.status)
+		{
+		case "disconnected":
+			Engine.DisconnectNetworkGame();
+			Engine.PopGuiPage();
+			messageBox(400, 200, "Connection to the server has been lost.", "Disconnected", 2);
+			break;
+		default:
+			error("Unrecognised netstatus type "+message.status);
+			break;
+		}
+		break;
+
 	case "gamesetup":
 		if (message.data) // (the host gets undefined data on first connect, so skip that)
 			g_GameAttributes = message.data;
@@ -80,6 +105,14 @@ function handleNetMessage(message)
 		break;
 
 	case "players":
+		// Find and report all joinings/leavings
+		for (var host in message.hosts)
+			if (! g_PlayerAssignments[host])
+				addChatMessage({ "type": "connect", "username": message.hosts[host].name });
+		for (var host in g_PlayerAssignments)
+			if (! message.hosts[host])
+				addChatMessage({ "type": "disconnect", "username": g_PlayerAssignments[host].name });
+		// Update the player list
 		g_PlayerAssignments = message.hosts;
 		updatePlayerList();
 		break;
@@ -88,6 +121,10 @@ function handleNetMessage(message)
 		Engine.PushGuiPage("page_loading.xml", { "attribs": g_GameAttributes });
 		break;
 
+	case "chat":
+		addChatMessage({ "type": "message", "username": message.username, "text": message.text });
+		break;
+
 	default:
 		error("Unrecognised net message type "+message.type);
 	}
@@ -257,3 +294,44 @@ function updatePlayerList()
 
 	g_IsInGuiUpdate = false;
 }
+
+function submitChatInput()
+{
+	var input = getGUIObjectByName("chatInput");
+	var text = input.caption;
+	if (text.length)
+	{
+		Engine.SendNetworkChat(text);
+		input.caption = "";
+	}
+}
+
+function addChatMessage(msg)
+{
+	// TODO: we ought to escape all values before displaying them,
+	// to prevent people inserting colours and newlines etc
+
+	var formatted;
+	switch (msg.type)
+	{
+	case "connect":
+		formatted = '[font="serif-bold-13"][color="255 0 0"]' + msg.username + '[/color][/font] [color="64 64 64"]has joined[/color]';
+		break;
+
+	case "disconnect":
+		formatted = '[font="serif-bold-13"][color="255 0 0"]' + msg.username + '[/color][/font] [color="64 64 64"]has left[/color]';
+		break;
+
+	case "message":
+		formatted = '[font="serif-bold-13"]<[color="255 0 0"]' + msg.username + '[/color]>[/font] ' + msg.text;
+		break;
+
+	default:
+		error("Invalid chat message '" + uneval(msg) + "'");
+		return;
+	}
+
+	g_ChatMessages.push(formatted);
+
+	getGUIObjectByName("chatText").caption = g_ChatMessages.join("\n");
+}
diff --git a/binaries/data/mods/public/gui/gamesetup/gamesetup.xml b/binaries/data/mods/public/gui/gamesetup/gamesetup.xml
index 4fc5daefe7..04fc080dd0 100644
--- a/binaries/data/mods/public/gui/gamesetup/gamesetup.xml
+++ b/binaries/data/mods/public/gui/gamesetup/gamesetup.xml
@@ -2,6 +2,7 @@
 
 <objects>
 
+	<script file="gui/common/functions_global_object.js"/>
 	<script file="gui/gamesetup/gamesetup.js"/>
 
 	<!-- Add a translucent black background to fade out the menu page -->
@@ -17,10 +18,13 @@
 
 		<object type="button" style="wheatExit" tooltip_style="snToolTip">
 			<action on="Press"><![CDATA[
+				cancelSetup();
 				Engine.PopGuiPage();
 			]]></action>
 		</object>
 
+		<!-- Map selection -->
+
 		<object size="0 0 250 100%">
 
 			<object name="mapSelection"
@@ -40,6 +44,8 @@
 
 		</object>
 
+		<!-- Player assignments -->
+
 		<object size="260 0 100% 100%-200" type="image" sprite="wheatIndentFillLight">
 			<repeat count="8">
 				<object name="playerBox[n]" size="0 0 100% 30">
@@ -49,13 +55,32 @@
 			</repeat>
 		</object>
 
+		<!-- Chat window -->
+
+		<object name="chatPanel" size="260 100%-190 100% 100%-45" type="image" sprite="wheatIndentFillLight">
+
+			<object name="chatText" size="3 1 100%-1 100%-25" type="text" style="chatPanel"/>
+
+			<object name="chatInput" size="2 100%-23 100%-66 100%-3" type="input" style="wheatInput">
+				<action on="Press">submitChatInput();</action>
+			</object>
+
+			<object size="100%-65 100%-25 100%-1 100%" type="button" style="wheatButton">
+				Send
+				<action on="Press">submitChatInput();</action>
+			</object>
+
+		</object>
+
+		<!-- Other things -->
+
 		<object name="onscreenToolTip"
 			type="text"
 			font="serif-14"
 			textcolor="white"
 			sprite="bkTranslucent"
 			hidden="true"
-			size="100%-300 100%-190 100% 100%-45"
+			size="260 100%-40 100%-150 100%"
 		>[Tooltip text]</object>
 
 		<object
diff --git a/binaries/data/mods/public/gui/gamesetup/styles.xml b/binaries/data/mods/public/gui/gamesetup/styles.xml
index ce93f29ff3..4470f15c0a 100644
--- a/binaries/data/mods/public/gui/gamesetup/styles.xml
+++ b/binaries/data/mods/public/gui/gamesetup/styles.xml
@@ -12,4 +12,16 @@
 		text_valign="center"
 	/>
 
+	<style name="chatPanel"
+		buffer_zone="5"
+		font="serif-13"
+		scrollbar="true"
+		scrollbar_style="wheatScrollBar"
+		scroll_bottom="true"
+		textcolor="black"
+		textcolor_selected="white"
+		text_align="left"
+		text_valign="center"
+	/>
+
 </styles>
diff --git a/binaries/data/mods/public/gui/session_new/session.js b/binaries/data/mods/public/gui/session_new/session.js
index 0a662afaef..e59ca57935 100644
--- a/binaries/data/mods/public/gui/session_new/session.js
+++ b/binaries/data/mods/public/gui/session_new/session.js
@@ -31,26 +31,49 @@ function getHotloadData()
 	return { selection: g_Selection.selected };
 }
 
-function changeNetStatus(status)
+function handleNetMessage(message)
 {
-	var obj = getGUIObjectByName("netStatus");
-	switch (status)
+	warn("Net message: "+uneval(message));
+
+	switch (message.type)
 	{
-	case "normal":
-		obj.caption = "";
-		obj.hidden = true;
-		break;
-	case "waiting_for_connect":
-		obj.caption = "Waiting for other players to connect";
-		obj.hidden = false;
+	case "netstatus":
+		var obj = getGUIObjectByName("netStatus");
+		switch (message.status)
+		{
+		case "waiting_for_players":
+			obj.caption = "Waiting for other players to connect";
+			obj.hidden = false;
+			break;
+		case "active":
+			obj.caption = "";
+			obj.hidden = true;
+			break;
+		case "disconnected":
+			obj.caption = "Connection to the server has been lost";
+			obj.hidden = false;
+			// TODO: we need to give players some way to exit
+			break;
+		default:
+			error("Unrecognised netstatus type "+message.status);
+			break;
+		}
 		break;
 	default:
-		error("Unexpected net status "+status);
+		error("Unrecognised net message type "+message.type);
 	}
 }
 
 function onTick()
 {
+	while (true)
+	{
+		var message = Engine.PollNetworkClient();
+		if (!message)
+			break;
+		handleNetMessage(message);
+	}
+
 	g_DevSettings.controlAll = getGUIObjectByName("devControlAll").checked;
 	// TODO: at some point this controlAll needs to disable the simulation code's
 	// player checks (once it has some player checks)
diff --git a/source/gui/CInput.cpp b/source/gui/CInput.cpp
index 4a95a2b431..5dda43204c 100644
--- a/source/gui/CInput.cpp
+++ b/source/gui/CInput.cpp
@@ -131,9 +131,9 @@ InReaction CInput::ManuallyHandleEvent(const SDL_Event_* ev)
 						*pCaption = pCaption->Left( m_iBufferPos-1 ) + 
 									pCaption->Right( (long) pCaption->length()-m_iBufferPos );
 
-					UpdateText(m_iBufferPos-1, m_iBufferPos, m_iBufferPos-1);
-					
 					--m_iBufferPos;
+					
+					UpdateText(m_iBufferPos, m_iBufferPos+1, m_iBufferPos);
 				}
 
 				UpdateAutoScroll();
@@ -413,13 +413,17 @@ InReaction CInput::ManuallyHandleEvent(const SDL_Event_* ev)
 			/* END: Message History Lookup */
 
 			case '\r':
-				// 'Return' should do nothing for singe liners
+				// 'Return' should do a Press event for single liners (e.g. submitting forms)
 				//  otherwise a '\n' character will be added.
 				{
 				bool multiline;
 				GUI<bool>::GetSetting(this, "multiline", multiline);
 				if (!multiline)
+				{
+					HandleMessage(GUIM_PRESSED);
+					ScriptEvent("press");
 					break;
+				}
 
 				cooked = '\n'; // Change to '\n' and do default:
 				// NOTE: Fall-through
@@ -630,7 +634,7 @@ void CInput::HandleMessage(const SGUIMessage &Message)
 	}
 }
 
-void CInput::Draw() 
+void CInput::Draw()
 {
 	float bz = GetBufferedZ();
 
@@ -1033,6 +1037,10 @@ void CInput::UpdateText(int from, int to_before, int to_after)
 	GUI<float>::GetSetting(this, "buffer_zone", buffer_zone);
 	GUI<bool>::GetSetting(this, "multiline", multiline);
 
+	// Ensure positions are valid after caption changes
+	m_iBufferPos = std::min(m_iBufferPos, (int)caption.size());
+	m_iBufferPos_Tail = std::min(m_iBufferPos_Tail, (int)caption.size());
+
 	if (font_name == CStrW())
 	{
 		// Destroy everything stored, there's no font, so there can be
diff --git a/source/gui/CText.cpp b/source/gui/CText.cpp
index 92906dafd2..27c0e85e53 100644
--- a/source/gui/CText.cpp
+++ b/source/gui/CText.cpp
@@ -39,6 +39,7 @@ CText::CText()
 	AddSetting(GUIST_CStrW,					"font");
 	AddSetting(GUIST_bool,					"scrollbar");
 	AddSetting(GUIST_CStr,					"scrollbar_style");
+	AddSetting(GUIST_bool,					"scroll_bottom");
 	AddSetting(GUIST_CGUISpriteInstance,	"sprite");
 	AddSetting(GUIST_EAlign,				"text_align");
 	AddSetting(GUIST_EVAlign,				"text_valign");
@@ -98,8 +99,22 @@ void CText::SetupText()
 	// Setup scrollbar
 	if (scrollbar)
 	{
-		GetScrollBar(0).SetScrollRange( m_GeneratedTexts[0]->m_Size.cy );
-		GetScrollBar(0).SetScrollSpace( m_CachedActualSize.GetHeight() );
+		bool scrollbottom = false;
+		GUI<bool>::GetSetting(this, "scroll_bottom", scrollbottom);
+
+		// If we are currently scrolled to the bottom of the text,
+		// then add more lines of text, update the scrollbar so we
+		// stick to the bottom.
+		// (Use 1.5px delta so this triggers the first time caption is set)
+		bool bottom = false;
+		if (scrollbottom && GetScrollBar(0).GetPos() > GetScrollBar(0).GetMaxPos() - 1.5f)
+			bottom = true;
+
+		GetScrollBar(0).SetScrollRange(m_GeneratedTexts[0]->m_Size.cy);
+		GetScrollBar(0).SetScrollSpace(m_CachedActualSize.GetHeight());
+
+		if (bottom)
+			GetScrollBar(0).SetPos(GetScrollBar(0).GetMaxPos());
 	}
 }
 
diff --git a/source/gui/IGUIScrollBar.h b/source/gui/IGUIScrollBar.h
index 3516a1de95..2d426a23b6 100644
--- a/source/gui/IGUIScrollBar.h
+++ b/source/gui/IGUIScrollBar.h
@@ -202,6 +202,11 @@ public:
 	 */
 	virtual void SetPos(const float &f) { m_Pos = f; UpdatePosBoundaries(); }
 
+	/**
+	 * Get the value of Pos that corresponds to the bottom of the scrollable region
+	 */
+	float GetMaxPos() const { return m_ScrollRange - m_ScrollSpace;	}
+
 	/**
 	 * Scroll towards 1.0 one step
 	 */
@@ -436,7 +441,7 @@ protected:
 
 	/**
 	 * Position of scroll bar, 0 means scrolled all the way to one side.
-	 * It is meassured in pixels, it is up to the host to make it actually
+	 * It is measured in pixels, it is up to the host to make it actually
 	 * apply in pixels.
 	 */
 	float m_Pos;
diff --git a/source/gui/scripting/ScriptFunctions.cpp b/source/gui/scripting/ScriptFunctions.cpp
index 69d780277d..d5c836f24a 100644
--- a/source/gui/scripting/ScriptFunctions.cpp
+++ b/source/gui/scripting/ScriptFunctions.cpp
@@ -218,13 +218,21 @@ void StartNetworkJoin(void* UNUSED(cbdata), std::wstring playerName, std::string
 	g_NetClient->SetupConnection(serverAddress);
 }
 
-// TODO: we need some way to disconnect the server/client
+void DisconnectNetworkGame(void* UNUSED(cbdata))
+{
+	// TODO: we ought to do async reliable disconnections
+
+	SAFE_DELETE(g_NetServer);
+	SAFE_DELETE(g_NetClient);
+	SAFE_DELETE(g_Game);
+}
 
 CScriptVal PollNetworkClient(void* cbdata)
 {
 	CGUIManager* guiManager = static_cast<CGUIManager*> (cbdata);
 
-	debug_assert(g_NetClient);
+	if (!g_NetClient)
+		return CScriptVal();
 
 	CScriptValRooted poll = g_NetClient->GuiPoll();
 
@@ -239,6 +247,14 @@ void AssignNetworkPlayer(void* UNUSED(cbdata), int playerID, std::string guid)
 	g_NetServer->AssignPlayer(playerID, guid);
 }
 
+void SendNetworkChat(void* UNUSED(cbdata), std::wstring message)
+{
+	debug_assert(g_NetClient);
+
+	g_NetClient->SendChatMessage(message);
+}
+
+
 } // namespace
 
 void GuiScriptingInit(ScriptInterface& scriptInterface)
@@ -264,9 +280,11 @@ void GuiScriptingInit(ScriptInterface& scriptInterface)
 	scriptInterface.RegisterFunction<void, CScriptVal, int, &StartGame>("StartGame");
 	scriptInterface.RegisterFunction<void, std::wstring, &StartNetworkHost>("StartNetworkHost");
 	scriptInterface.RegisterFunction<void, std::wstring, std::string, &StartNetworkJoin>("StartNetworkJoin");
+	scriptInterface.RegisterFunction<void, &DisconnectNetworkGame>("DisconnectNetworkGame");
 	scriptInterface.RegisterFunction<CScriptVal, &PollNetworkClient>("PollNetworkClient");
 	scriptInterface.RegisterFunction<void, CScriptVal, &SetNetworkGameAttributes>("SetNetworkGameAttributes");
 	scriptInterface.RegisterFunction<void, int, std::string, &AssignNetworkPlayer>("AssignNetworkPlayer");
+	scriptInterface.RegisterFunction<void, std::wstring, &SendNetworkChat>("SendNetworkChat");
 
 	// Misc functions
 	scriptInterface.RegisterFunction<std::wstring, std::wstring, &SetCursor>("SetCursor");
diff --git a/source/network/NetClient.cpp b/source/network/NetClient.cpp
index 20b0352f9e..80f6195ed1 100644
--- a/source/network/NetClient.cpp
+++ b/source/network/NetClient.cpp
@@ -53,14 +53,17 @@ CNetClient::CNetClient(CGame* game) :
 
 	AddTransition(NCS_INITIAL_GAMESETUP, (uint)NMT_GAME_SETUP, NCS_PREGAME, (void*)&OnGameSetup, context);
 
+	AddTransition(NCS_PREGAME, (uint)NMT_CHAT, NCS_PREGAME, (void*)&OnChat, context);
 	AddTransition(NCS_PREGAME, (uint)NMT_GAME_SETUP, NCS_PREGAME, (void*)&OnGameSetup, context);
 	AddTransition(NCS_PREGAME, (uint)NMT_PLAYER_ASSIGNMENT, NCS_PREGAME, (void*)&OnPlayerAssignment, context);
 	AddTransition(NCS_PREGAME, (uint)NMT_GAME_START, NCS_LOADING, (void*)&OnGameStart, context);
 
+	AddTransition(NCS_LOADING, (uint)NMT_CHAT, NCS_LOADING, (void*)&OnChat, context);
 	AddTransition(NCS_LOADING, (uint)NMT_GAME_SETUP, NCS_LOADING, (void*)&OnGameSetup, context);
 	AddTransition(NCS_LOADING, (uint)NMT_PLAYER_ASSIGNMENT, NCS_LOADING, (void*)&OnPlayerAssignment, context);
 	AddTransition(NCS_LOADING, (uint)NMT_LOADED_GAME, NCS_INGAME, (void*)&OnLoadedGame, context);
 
+	AddTransition(NCS_INGAME, (uint)NMT_CHAT, NCS_INGAME, (void*)&OnChat, context);
 	AddTransition(NCS_INGAME, (uint)NMT_GAME_SETUP, NCS_INGAME, (void*)&OnGameSetup, context);
 	AddTransition(NCS_INGAME, (uint)NMT_PLAYER_ASSIGNMENT, NCS_INGAME, (void*)&OnPlayerAssignment, context);
 	AddTransition(NCS_INGAME, (uint)NMT_SIMULATION_COMMAND, NCS_INGAME, (void*)&OnInGame, context);
@@ -178,7 +181,16 @@ void CNetClient::HandleConnect()
 
 void CNetClient::HandleDisconnect()
 {
-	// TODO: should do something
+	CScriptValRooted msg;
+	GetScriptInterface().Eval("({'type':'netstatus','status':'disconnected'})", msg);
+	PushGuiMessage(msg);
+}
+
+void CNetClient::SendChatMessage(const std::wstring& text)
+{
+	CChatMessage chat;
+	chat.m_Message = text;
+	SendMessage(&chat);
 }
 
 bool CNetClient::HandleMessage(CNetMessage* message)
@@ -192,7 +204,9 @@ bool CNetClient::HandleMessage(CNetMessage* message)
 
 void CNetClient::LoadFinished()
 {
-	m_Game->ChangeNetStatus(CGame::NET_WAITING_FOR_CONNECT);
+	CScriptValRooted msg;
+	GetScriptInterface().Eval("({'type':'netstatus','status':'waiting_for_players'})", msg);
+	PushGuiMessage(msg);
 
 	CLoadedGameMessage loaded;
 	SendMessage(&loaded);
@@ -260,6 +274,23 @@ bool CNetClient::OnAuthenticate(void* context, CFsmEvent* event)
 	return true;
 }
 
+bool CNetClient::OnChat(void* context, CFsmEvent* event)
+{
+	debug_assert(event->GetType() == (uint)NMT_CHAT);
+
+	CNetClient* client = (CNetClient*)context;
+
+	CChatMessage* message = (CChatMessage*)event->GetParamRef();
+
+	CScriptValRooted msg;
+	client->GetScriptInterface().Eval("({'type':'chat'})", msg);
+	client->GetScriptInterface().SetProperty(msg.get(), "username", std::wstring(message->m_Sender), false);
+	client->GetScriptInterface().SetProperty(msg.get(), "text", std::wstring(message->m_Message), false);
+	client->PushGuiMessage(msg);
+
+	return true;
+}
+
 bool CNetClient::OnGameSetup(void* context, CFsmEvent* event)
 {
 	debug_assert(event->GetType() == (uint)NMT_GAME_SETUP);
@@ -287,15 +318,17 @@ bool CNetClient::OnPlayerAssignment(void* context, CFsmEvent* event)
 	CPlayerAssignmentMessage* message = (CPlayerAssignmentMessage*)event->GetParamRef();
 
 	// Unpack the message
-	client->m_PlayerAssignments.clear();
+	PlayerAssignmentMap newPlayerAssignments;
 	for (size_t i = 0; i < message->m_Hosts.size(); ++i)
 	{
 		PlayerAssignment assignment;
 		assignment.m_Name = message->m_Hosts[i].m_Name;
 		assignment.m_PlayerID = message->m_Hosts[i].m_PlayerID;
-		client->m_PlayerAssignments[message->m_Hosts[i].m_GUID] = assignment;
+		newPlayerAssignments[message->m_Hosts[i].m_GUID] = assignment;
 	}
 
+	client->m_PlayerAssignments.swap(newPlayerAssignments);
+
 	client->PostPlayerAssignmentsToScript();
 
 	return true;
@@ -333,7 +366,10 @@ bool CNetClient::OnLoadedGame(void* context, CFsmEvent* event)
 	// All players have loaded the game - start running the turn manager
 	// so that the game begins
 	client->m_Game->SetTurnManager(client->m_ClientTurnManager);
-	client->m_Game->ChangeNetStatus(CGame::NET_NORMAL);
+
+	CScriptValRooted msg;
+	client->GetScriptInterface().Eval("({'type':'netstatus','status':'active'})", msg);
+	client->PushGuiMessage(msg);
 
 	return true;
 }
diff --git a/source/network/NetClient.h b/source/network/NetClient.h
index e34cde2420..7fb5d8add0 100644
--- a/source/network/NetClient.h
+++ b/source/network/NetClient.h
@@ -153,6 +153,8 @@ public:
 	 */
 	void LoadFinished();
 
+	void SendChatMessage(const std::wstring& text);
+
 private:
 	// Net message / FSM transition handlers
 	static bool OnConnect(void* context, CFsmEvent* event);
diff --git a/source/network/NetMessages.h b/source/network/NetMessages.h
index bed1e1ba3a..7a127473f9 100644
--- a/source/network/NetMessages.h
+++ b/source/network/NetMessages.h
@@ -38,6 +38,7 @@
 enum NetMessageType
 {
 	NMT_CONNECT_COMPLETE = -256,	// Connection is complete
+	NMT_CONNECTION_LOST,
 	NMT_INVALID = 0,		// Invalid message
 	NMT_SERVER_HANDSHAKE,	// Handshake stage
 	NMT_CLIENT_HANDSHAKE,
@@ -106,8 +107,7 @@ START_NMT_CLASS_(AuthenticateResult, NMT_AUTHENTICATE_RESULT)
 END_NMT_CLASS()
 
 START_NMT_CLASS_(Chat, NMT_CHAT)
-	NMT_FIELD(CStrW, m_Sender)
-	NMT_FIELD_INT(m_Recipient, u32, 2)
+	NMT_FIELD(CStrW, m_Sender) // ignored when client->server, valid when server->client
 	NMT_FIELD(CStrW, m_Message)
 END_NMT_CLASS()
 
diff --git a/source/network/NetServer.cpp b/source/network/NetServer.cpp
index 76bfd765a9..1cfc735ed2 100644
--- a/source/network/NetServer.cpp
+++ b/source/network/NetServer.cpp
@@ -59,6 +59,17 @@ CNetServer::CNetServer() :
 
 CNetServer::~CNetServer()
 {
+	for (size_t i = 0; i < m_Sessions.size(); ++i)
+	{
+		m_Sessions[i]->Disconnect();
+		delete m_Sessions[i];
+	}
+
+	if (m_Host)
+	{
+		enet_host_destroy(m_Host);
+	}
+
 	m_GameAttributes = CScriptValRooted(); // clear root before deleting its context
 	delete m_ScriptInterface;
 }
@@ -182,6 +193,8 @@ void CNetServer::Poll()
 			{
 				LOGMESSAGE(L"Net server: %hs disconnected", DebugName(session).c_str());
 
+				session->Update((uint)NMT_CONNECTION_LOST, NULL);
+
 				HandleDisconnect(session);
 
 				delete session;
@@ -251,10 +264,16 @@ void CNetServer::SetupSession(CNetServerSession* session)
 	void* context = session;
 
 	// Set up transitions for session
+	session->AddTransition(NSS_HANDSHAKE, (uint)NMT_CONNECTION_LOST, NSS_UNCONNECTED, (void*)&OnDisconnect, context);
 	session->AddTransition(NSS_HANDSHAKE, (uint)NMT_CLIENT_HANDSHAKE, NSS_AUTHENTICATE, (void*)&OnClientHandshake, context);
+
 	session->AddTransition(NSS_AUTHENTICATE, (uint)NMT_AUTHENTICATE, NSS_PREGAME, (void*)&OnAuthenticate, context);
+
+	session->AddTransition(NSS_PREGAME, (uint)NMT_CONNECTION_LOST, NSS_UNCONNECTED, (void*)&OnDisconnect, context);
 	session->AddTransition(NSS_PREGAME, (uint)NMT_CHAT, NSS_PREGAME, (void*)&OnChat, context);
 	session->AddTransition(NSS_PREGAME, (uint)NMT_LOADED_GAME, NSS_INGAME, (void*)&OnLoadedGame, context);
+
+	session->AddTransition(NSS_INGAME, (uint)NMT_CONNECTION_LOST, NSS_UNCONNECTED, (void*)&OnDisconnect, context);
 	session->AddTransition(NSS_INGAME, (uint)NMT_CHAT, NSS_INGAME, (void*)&OnChat, context);
 	session->AddTransition(NSS_INGAME, (uint)NMT_SIMULATION_COMMAND, NSS_INGAME, (void*)&OnInGame, context);
 	session->AddTransition(NSS_INGAME, (uint)NMT_SYNC_CHECK, NSS_INGAME, (void*)&OnInGame, context);
@@ -298,6 +317,13 @@ void CNetServer::OnUserJoin(CNetServerSession* session)
 	OnAddPlayer();
 }
 
+void CNetServer::OnUserLeave(CNetServerSession* session)
+{
+	RemovePlayer(session->GetGUID());
+
+	OnRemovePlayer();
+}
+
 void CNetServer::AddPlayer(const CStr& guid, const CStrW& name)
 {
 	// Find the first free player ID
@@ -326,6 +352,8 @@ void CNetServer::RemovePlayer(const CStr& guid)
 {
 	m_PlayerAssignments.erase(guid);
 
+	SendPlayerAssignments();
+
 	OnRemovePlayer();
 }
 
@@ -407,7 +435,9 @@ bool CNetServer::OnAuthenticate(void* context, CFsmEvent* event)
 
 	u32 newHostID = server.m_NextHostID++;
 
-	session->SetUserName(message->m_Name);
+	CStrW username = server.DeduplicatePlayerName(SanitisePlayerName(message->m_Name));
+
+	session->SetUserName(username);
 	session->SetGUID(message->m_GUID);
 	session->SetHostID(newHostID);
 
@@ -463,6 +493,7 @@ bool CNetServer::OnChat(void* context, CFsmEvent* event)
 	CNetServer& server = session->GetServer();
 
 	CChatMessage* message = (CChatMessage*)event->GetParamRef();
+
 	message->m_Sender = session->GetUserName();
 
 	server.Broadcast(message);
@@ -482,6 +513,20 @@ bool CNetServer::OnLoadedGame(void* context, CFsmEvent* event)
 	return true;
 }
 
+bool CNetServer::OnDisconnect(void* context, CFsmEvent* event)
+{
+	debug_assert(event->GetType() == (uint)NMT_CONNECTION_LOST);
+
+	CNetServerSession* session = (CNetServerSession*)context;
+	CNetServer& server = session->GetServer();
+
+	// If the user had authenticated, we need to handle their leaving
+	if (session->GetCurrState() == NSS_PREGAME || session->GetCurrState() == NSS_INGAME)
+		server.OnUserLeave(session);
+
+	return true;
+}
+
 void CNetServer::CheckGameLoadStatus(CNetServerSession* changedSession)
 {
 	for (size_t i = 0; i < m_Sessions.size(); ++i)
@@ -524,3 +569,49 @@ void CNetServer::UpdateGameAttributes(const CScriptValRooted& attrs)
 	gameSetupMessage.m_Data = m_GameAttributes;
 	Broadcast(&gameSetupMessage);
 }
+
+CStrW CNetServer::SanitisePlayerName(const CStrW& original)
+{
+	const size_t MAX_LENGTH = 32;
+
+	CStrW name = original;
+	name.Replace(L"[", L"{"); // remove GUI tags
+	name.Replace(L"]", L"}"); // remove for symmetry
+
+	// Restrict the length
+	if (name.length() > MAX_LENGTH)
+		name = name.Left(MAX_LENGTH);
+
+	// Don't allow surrounding whitespace
+	name.Trim(PS_TRIM_BOTH);
+
+	// Don't allow empty name
+	if (name.empty())
+		name = L"Anonymous";
+
+	return name;
+}
+
+CStrW CNetServer::DeduplicatePlayerName(const CStrW& original)
+{
+	CStrW name = original;
+
+	size_t id = 2;
+	while (true)
+	{
+		bool unique = true;
+		for (size_t i = 0; i < m_Sessions.size(); ++i)
+		{
+			if (m_Sessions[i]->GetUserName() == name)
+			{
+				unique = false;
+				break;
+			}
+		}
+
+		if (unique)
+			return name;
+
+		name = original + L" (" + CStrW(id++) + L")";
+	}
+}
diff --git a/source/network/NetServer.h b/source/network/NetServer.h
index 2adc139bac..6f8f63dcb4 100644
--- a/source/network/NetServer.h
+++ b/source/network/NetServer.h
@@ -58,6 +58,7 @@ enum NetServerState
  */
 enum
 {
+	NSS_UNCONNECTED,
 	NSS_HANDSHAKE,
 	NSS_AUTHENTICATE,
 	NSS_PREGAME,
@@ -143,6 +144,16 @@ public:
 	 */
 	void UpdateGameAttributes(const CScriptValRooted& attrs);
 
+	/**
+	 * Make a player name 'nicer' by limiting the length and removing forbidden characters etc.
+	 */
+	static CStrW SanitisePlayerName(const CStrW& original);
+
+	/**
+	 * Make a player name unique, if it matches any existing session's name.
+	 */
+	CStrW DeduplicatePlayerName(const CStrW& original);
+
 	/**
 	 * Get the script context used for game attributes.
 	 */
@@ -165,13 +176,16 @@ private:
 	void SetupSession(CNetServerSession* session);
 	bool HandleConnect(CNetServerSession* session);
 	bool HandleDisconnect(CNetServerSession* session);
+
 	void OnUserJoin(CNetServerSession* session);
+	void OnUserLeave(CNetServerSession* session);
 
 	static bool OnClientHandshake(void* context, CFsmEvent* event);
 	static bool OnAuthenticate(void* context, CFsmEvent* event);
 	static bool OnInGame(void* context, CFsmEvent* event);
 	static bool OnChat(void* context, CFsmEvent* event);
 	static bool OnLoadedGame(void* context, CFsmEvent* event);
+	static bool OnDisconnect(void* context, CFsmEvent* event);
 
 	void CheckGameLoadStatus(CNetServerSession* changedSession);
 
diff --git a/source/network/NetSession.cpp b/source/network/NetSession.cpp
index 420978f39a..a0d1c40644 100644
--- a/source/network/NetSession.cpp
+++ b/source/network/NetSession.cpp
@@ -38,6 +38,9 @@ CNetClientSession::~CNetClientSession()
 }
 
 
+// TODO: the whole disconnection process is a tangled mess - need
+// to sort out exactly what happens at what times, and the interactions
+// between ENet and session and client and GUI
 
 CNetClientSessionRemote::CNetClientSessionRemote(CNetClient& client) :
 	CNetClientSession(client), m_Host(NULL), m_Server(NULL)
@@ -46,7 +49,15 @@ CNetClientSessionRemote::CNetClientSessionRemote(CNetClient& client) :
 
 CNetClientSessionRemote::~CNetClientSessionRemote()
 {
+	if (m_Host && m_Server)
+	{
+		// Disconnect without waiting for confirmation
+		enet_peer_disconnect_now(m_Server, 0);
+		enet_host_destroy(m_Host);
 
+		m_Host = NULL;
+		m_Server = NULL;
+	}
 }
 
 bool CNetClientSessionRemote::Connect(u16 port, const CStr& server)
@@ -176,7 +187,7 @@ void CNetClientSessionLocal::Poll()
 
 void CNetClientSessionLocal::Disconnect()
 {
-	// TODO
+	GetClient().HandleDisconnect();
 }
 
 bool CNetClientSessionLocal::SendMessage(const CNetMessage* message)
@@ -216,7 +227,8 @@ CNetServerSessionRemote::CNetServerSessionRemote(CNetServer& server, ENetPeer* p
 
 void CNetServerSessionRemote::Disconnect()
 {
-	// TODO
+	// TODO: ought to do reliable async disconnects, probably
+	enet_peer_disconnect_now(m_Peer, 0);
 }
 
 bool CNetServerSessionRemote::SendMessage(const CNetMessage* message)
@@ -233,7 +245,7 @@ CNetServerSessionLocal::CNetServerSessionLocal(CNetServer& server, CNetClientSes
 
 void CNetServerSessionLocal::Disconnect()
 {
-	// TODO
+	m_ClientSession.Disconnect();
 }
 
 bool CNetServerSessionLocal::SendMessage(const CNetMessage* message)
diff --git a/source/ps/Game.cpp b/source/ps/Game.cpp
index de5cc78fee..7f95b81ef9 100644
--- a/source/ps/Game.cpp
+++ b/source/ps/Game.cpp
@@ -165,21 +165,6 @@ PSRETURN CGame::ReallyStartGame()
 	return 0;
 }
 
-void CGame::ChangeNetStatus(ENetStatus status)
-{
-	if (g_GUI && g_GUI->HasPages())
-	{
-		const char* statusStr = "?";
-		switch (status)
-		{
-		case NET_WAITING_FOR_CONNECT: statusStr = "waiting_for_connect"; break;
-		case NET_NORMAL: statusStr = "normal"; break;
-		}
-
-		g_GUI->GetScriptInterface().CallFunctionVoid(OBJECT_TO_JSVAL(g_GUI->GetScriptObject()), "changeNetStatus", statusStr);
-	}
-}
-
 int CGame::GetPlayerID()
 {
 	return m_PlayerID;
diff --git a/source/ps/Game.h b/source/ps/Game.h
index c4fa2e8a11..ec8ee60816 100644
--- a/source/ps/Game.h
+++ b/source/ps/Game.h
@@ -98,11 +98,6 @@ public:
 	void StartGame(const CScriptValRooted& attribs);
 	PSRETURN ReallyStartGame();
 
-	/**
-	 * Notify the game of changes in the network connection status.
-	 */
-	void ChangeNetStatus(ENetStatus status);
-
 	/*
 		Perform all per-frame updates
 	*/
diff --git a/source/ps/GameSetup/GameSetup.cpp b/source/ps/GameSetup/GameSetup.cpp
index 2853a5a61e..c4b97378e3 100644
--- a/source/ps/GameSetup/GameSetup.cpp
+++ b/source/ps/GameSetup/GameSetup.cpp
@@ -568,8 +568,7 @@ void Shutdown(int UNUSED(flags))
 {
 	MICROLOG(L"Shutdown");
 
-	if (g_Game)
-		EndGame();
+	EndGame();
 
 	ShutdownPs(); // Must delete g_GUI before g_ScriptingHost