diff --git a/docs/net_protocol.txt b/docs/net_protocol.txt
index 651d9549..40ecec0a 100644
--- a/docs/net_protocol.txt
+++ b/docs/net_protocol.txt
@@ -427,7 +427,7 @@ Client Request: Leave Current Game
 (will be answered with a Server Notification: Removed From Game)
 
 
-Client Request: Start Event
+Client Request/Server Request: Start Event
 
 	 0                   1                   2                   3
 	 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
@@ -436,10 +436,23 @@ Client Request: Start Event
 	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 	|          Start Flags          |           Reserved            |
 	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+(sent by one client, repeated to everyone by the server)
 Start Flags:
 	0x01 set: Fill up with computer opponents.
 
 
+Client Reply: Start Event ACK
+
+	 0                   1                   2                   3
+	 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	|        Message Type = 67      |     Message Length = 8        |
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	|                            Reserved                           |
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+(every client must confirm the start event)
+
+
 Server Notification: Game Start
 
 	 0                   1                   2                   3
diff --git a/src/net/clientstate.h b/src/net/clientstate.h
index 0a49ba43..b13269a7 100644
--- a/src/net/clientstate.h
+++ b/src/net/clientstate.h
@@ -234,6 +234,41 @@ protected:
 	virtual int InternalProcess(ClientThread &client, boost::shared_ptr<NetPacket> packet);
 };
 
+// State: Synchronize on game start.
+class ClientStateSynchronizeStart : public AbstractClientStateReceiving
+{
+public:
+	// Access the state singleton.
+	static ClientStateSynchronizeStart &Instance();
+
+	virtual ~ClientStateSynchronizeStart();
+
+	virtual int Process(ClientThread &client);
+protected:
+
+	// Protected constructor - this is a singleton.
+	ClientStateSynchronizeStart();
+
+	virtual int InternalProcess(ClientThread &client, boost::shared_ptr<NetPacket> packet);
+};
+
+// State: Wait for game start.
+class ClientStateWaitStart : public AbstractClientStateReceiving
+{
+public:
+	// Access the state singleton.
+	static ClientStateWaitStart &Instance();
+
+	virtual ~ClientStateWaitStart();
+
+protected:
+
+	// Protected constructor - this is a singleton.
+	ClientStateWaitStart();
+
+	virtual int InternalProcess(ClientThread &client, boost::shared_ptr<NetPacket> packet);
+};
+
 // State: Wait for start of the next hand.
 class ClientStateWaitHand : public AbstractClientStateReceiving
 {
diff --git a/src/net/clientthread.h b/src/net/clientthread.h
index c43fe903..947e2240 100644
--- a/src/net/clientthread.h
+++ b/src/net/clientthread.h
@@ -86,7 +86,7 @@ protected:
 
 	bool GetCachedPlayerInfo(unsigned id, PlayerInfo &info) const;
 	void RequestPlayerInfo(unsigned id);
-	void SetPlayerInfo(unsigned id, const PlayerInfo &info);
+	void SetPlayerInfo(unsigned id, const PlayerInfo &info, bool retrieveAvatar = true);
 	void SetNewGameAdmin(unsigned id);
 
 	void AddTempAvatarData(unsigned playerId, unsigned avatarSize, AvatarFileType type);
@@ -134,6 +134,8 @@ protected:
 	bool IsSessionEstablished() const;
 	void SetSessionEstablished(bool flag);
 
+	bool IsSynchronized() const;
+
 private:
 
 	NetPacketList m_outPacketList;
@@ -177,6 +179,8 @@ friend class ClientStateStartSession;
 friend class ClientStateWaitSession;
 friend class ClientStateWaitJoin;
 friend class ClientStateWaitGame;
+friend class ClientStateSynchronizeStart;
+friend class ClientStateWaitStart;
 friend class ClientStateWaitHand;
 friend class ClientStateRunHand;
 friend class ClientStateFinal;
diff --git a/src/net/common/clientstate.cpp b/src/net/common/clientstate.cpp
index 00241ce8..f8129b39 100644
--- a/src/net/common/clientstate.cpp
+++ b/src/net/common/clientstate.cpp
@@ -395,16 +395,6 @@ AbstractClientStateReceiving::Process(ClientThread &client)
 			NetPacketPlayerInfo::Data infoData;
 			tmpPacket->ToNetPacketPlayerInfo()->GetData(infoData);
 			client.SetPlayerInfo(infoData.playerId, infoData.playerInfo);
-			// Retrieve avatar if needed.
-			if (infoData.playerInfo.hasAvatar && !client.GetAvatarManager().HasAvatar(infoData.playerInfo.avatar))
-			{
-				boost::shared_ptr<NetPacket> retrieveAvatar(new NetPacketRetrieveAvatar);
-				NetPacketRetrieveAvatar::Data retrieveAvatarData;
-				retrieveAvatarData.requestId = infoData.playerId;
-				retrieveAvatarData.avatar = infoData.playerInfo.avatar;
-				static_cast<NetPacketRetrieveAvatar *>(retrieveAvatar.get())->SetData(retrieveAvatarData);
-				client.GetSender().Send(client.GetContext().GetSocket(), retrieveAvatar);
-			}
 		}
 		else if (tmpPacket->ToNetPacketRemovedFromGame())
 		{
@@ -651,33 +641,9 @@ ClientStateWaitGame::InternalProcess(ClientThread &client, boost::shared_ptr<Net
 {
 	int retVal = MSG_SOCK_INTERNAL_PENDING;
 
-	if (packet->ToNetPacketGameStart())
+	if (packet->ToNetPacketStartEvent())
 	{
-		// Start the network game as client.
-		NetPacketGameStart::Data gameStartData;
-		packet->ToNetPacketGameStart()->GetData(gameStartData);
-
-		client.SetStartData(gameStartData.startData);
-
-		// Set player numbers using the game start data slots.
-		NetPacketGameStart::PlayerSlotList::const_iterator slot_i = gameStartData.playerSlots.begin();
-		NetPacketGameStart::PlayerSlotList::const_iterator slot_end = gameStartData.playerSlots.end();
-		int num = 0;
-
-		while (slot_i != slot_end)
-		{
-			unsigned playerId = (*slot_i).playerId;
-			boost::shared_ptr<PlayerData> tmpPlayer = client.GetPlayerDataByUniqueId(playerId);
-			if (!tmpPlayer.get())
-				throw ClientException(ERR_NET_UNKNOWN_PLAYER_ID, 0);
-			tmpPlayer->SetNumber(num);
-
-			++num;
-			++slot_i;
-		}
-
-		client.SetState(ClientStateWaitHand::Instance());
-		retVal = MSG_NET_GAME_CLIENT_START;
+		client.SetState(ClientStateSynchronizeStart::Instance());
 	}
 	else if (packet->ToNetPacketPlayerJoined())
 	{
@@ -719,6 +685,103 @@ ClientStateWaitGame::InternalProcess(ClientThread &client, boost::shared_ptr<Net
 
 //-----------------------------------------------------------------------------
 
+ClientStateSynchronizeStart &
+ClientStateSynchronizeStart::Instance()
+{
+	static ClientStateSynchronizeStart state;
+	return state;
+}
+
+ClientStateSynchronizeStart::ClientStateSynchronizeStart()
+{
+}
+
+ClientStateSynchronizeStart::~ClientStateSynchronizeStart()
+{
+}
+
+int
+ClientStateSynchronizeStart::Process(ClientThread &client)
+{
+	int retVal = AbstractClientStateReceiving::Process(client);
+
+	if (client.IsSynchronized())
+	{
+		boost::shared_ptr<NetPacket> startAck(new NetPacketStartEventAck);
+		client.GetSender().Send(client.GetContext().GetSocket(), startAck);
+		client.SetState(ClientStateWaitStart::Instance());
+	}
+
+	return retVal;
+}
+
+int
+ClientStateSynchronizeStart::InternalProcess(ClientThread &client, boost::shared_ptr<NetPacket> packet)
+{
+	int retVal = MSG_SOCK_INTERNAL_PENDING;
+
+	if (packet->ToNetPacketGameStart())
+		throw ClientException(ERR_NET_START_TIMEOUT, 0);
+
+	return retVal;
+}
+
+//-----------------------------------------------------------------------------
+
+ClientStateWaitStart &
+ClientStateWaitStart::Instance()
+{
+	static ClientStateWaitStart state;
+	return state;
+}
+
+ClientStateWaitStart::ClientStateWaitStart()
+{
+}
+
+ClientStateWaitStart::~ClientStateWaitStart()
+{
+}
+
+int
+ClientStateWaitStart::InternalProcess(ClientThread &client, boost::shared_ptr<NetPacket> packet)
+{
+	int retVal = MSG_SOCK_INTERNAL_PENDING;
+
+	if (packet->ToNetPacketGameStart())
+	{
+		// Start the network game as client.
+		NetPacketGameStart::Data gameStartData;
+		packet->ToNetPacketGameStart()->GetData(gameStartData);
+
+		client.SetStartData(gameStartData.startData);
+
+		// Set player numbers using the game start data slots.
+		NetPacketGameStart::PlayerSlotList::const_iterator slot_i = gameStartData.playerSlots.begin();
+		NetPacketGameStart::PlayerSlotList::const_iterator slot_end = gameStartData.playerSlots.end();
+		int num = 0;
+
+		while (slot_i != slot_end)
+		{
+			unsigned playerId = (*slot_i).playerId;
+			boost::shared_ptr<PlayerData> tmpPlayer = client.GetPlayerDataByUniqueId(playerId);
+			if (!tmpPlayer.get())
+				throw ClientException(ERR_NET_UNKNOWN_PLAYER_ID, 0);
+			tmpPlayer->SetNumber(num);
+
+			++num;
+			++slot_i;
+		}
+
+		client.SetState(ClientStateWaitHand::Instance());
+		retVal = MSG_NET_GAME_CLIENT_START;
+	}
+
+	return retVal;
+}
+
+//-----------------------------------------------------------------------------
+
 ClientStateWaitHand &
 ClientStateWaitHand::Instance()
 {
diff --git a/src/net/common/clientthread.cpp b/src/net/common/clientthread.cpp
index 7177d0b0..05596fe8 100644
--- a/src/net/common/clientthread.cpp
+++ b/src/net/common/clientthread.cpp
@@ -381,7 +381,7 @@ ClientThread::RequestPlayerInfo(unsigned id)
 }
 
 void
-ClientThread::SetPlayerInfo(unsigned id, const PlayerInfo &info)
+ClientThread::SetPlayerInfo(unsigned id, const PlayerInfo &info, bool retrieveAvatar)
 {
 	{
 		boost::mutex::scoped_lock lock(m_playerInfoMapMutex);
@@ -404,6 +404,23 @@ ClientThread::SetPlayerInfo(unsigned id, const PlayerInfo &info)
 		}
 	}
 
+	// Retrieve avatar if needed.
+	if (retrieveAvatar && info.hasAvatar && !GetAvatarManager().HasAvatar(info.avatar))
+	{
+		boost::shared_ptr<NetPacket> retrieveAvatar(new NetPacketRetrieveAvatar);
+		NetPacketRetrieveAvatar::Data retrieveAvatarData;
+		retrieveAvatarData.requestId = id;
+		retrieveAvatarData.avatar = info.avatar;
+		static_cast<NetPacketRetrieveAvatar *>(retrieveAvatar.get())->SetData(retrieveAvatarData);
+		GetSender().Send(GetContext().GetSocket(), retrieveAvatar);
+
+		// Insert empty value in list to synchronize waiting.
+		m_tempAvatarMap[id] = boost::shared_ptr<AvatarData>();
+	}
+
+	// Remove from request list.
+	m_playerInfoRequestList.remove(id);
+
 	// Notify GUI
 	GetCallback().SignalNetClientPlayerChanged(id, info.playerName);
 
@@ -464,7 +481,7 @@ ClientThread::CompleteTempAvatarData(unsigned playerId)
 	m_tempAvatarMap.erase(pos);
 
 	// Update player info, but never re-request avatar.
-	SetPlayerInfo(playerId, tmpPlayerInfo);
+	SetPlayerInfo(playerId, tmpPlayerInfo, false);
 }
 
 const ClientContext &
@@ -822,3 +839,9 @@ ClientThread::SetSessionEstablished(bool flag)
 	m_sessionEstablished = flag;
 }
 
+bool
+ClientThread::IsSynchronized() const
+{
+	return (m_playerInfoRequestList.empty() && m_tempAvatarMap.empty());
+}
+
diff --git a/src/net/common/netpacket.cpp b/src/net/common/netpacket.cpp
index f04a9a07..1db4ef4a 100644
--- a/src/net/common/netpacket.cpp
+++ b/src/net/common/netpacket.cpp
@@ -49,6 +49,7 @@ using namespace std;
 #define NET_TYPE_KICK_PLAYER					0x0040
 #define NET_TYPE_LEAVE_CURRENT_GAME				0x0041
 #define NET_TYPE_START_EVENT					0x0042
+#define NET_TYPE_START_EVENT_ACK				0x0043
 #define NET_TYPE_GAME_START						0x0050
 #define NET_TYPE_HAND_START						0x0051
 #define NET_TYPE_PLAYERS_TURN					0x0052
@@ -297,6 +298,12 @@ struct GCC_PACKED NetPacketStartEventData
 	u_int16_t			reserved;
 };
 
+struct GCC_PACKED NetPacketStartEventAckData
+{
+	NetPacketHeader		head;
+	u_int32_t			reserved;
+};
+
 struct GCC_PACKED NetPacketGameStartData
 {
 	NetPacketHeader		head;
@@ -646,6 +653,9 @@ NetPacket::Create(char *data, unsigned &dataSize)
 				case NET_TYPE_START_EVENT:
 					tmpPacket = boost::shared_ptr<NetPacket>(new NetPacketStartEvent);
 					break;
+				case NET_TYPE_START_EVENT_ACK:
+					tmpPacket = boost::shared_ptr<NetPacket>(new NetPacketStartEventAck);
+					break;
 				case NET_TYPE_GAME_START:
 					tmpPacket = boost::shared_ptr<NetPacket>(new NetPacketGameStart);
 					break;
@@ -913,6 +923,12 @@ NetPacket::ToNetPacketStartEvent() const
 	return NULL;
 }
 
+const NetPacketStartEventAck *
+NetPacket::ToNetPacketStartEventAck() const
+{
+	return NULL;
+}
+
 const NetPacketGameStart *
 NetPacket::ToNetPacketGameStart() const
 {
@@ -2641,7 +2657,7 @@ NetPacketKickPlayer::InternalCheck(const NetPacketHeader*) const
 //-----------------------------------------------------------------------------
 
 NetPacketLeaveCurrentGame::NetPacketLeaveCurrentGame()
-: NetPacket(NET_TYPE_LEAVE_CURRENT_GAME, sizeof(NetPacketLeaveCurrentGame), sizeof(NetPacketLeaveCurrentGame))
+: NetPacket(NET_TYPE_LEAVE_CURRENT_GAME, sizeof(NetPacketLeaveCurrentGameData), sizeof(NetPacketLeaveCurrentGameData))
 {
 }
 
@@ -2735,6 +2751,43 @@ NetPacketStartEvent::InternalCheck(const NetPacketHeader*) const
 
 //-----------------------------------------------------------------------------
 
+NetPacketStartEventAck::NetPacketStartEventAck()
+: NetPacket(NET_TYPE_START_EVENT_ACK, sizeof(NetPacketStartEventAckData), sizeof(NetPacketStartEventAckData))
+{
+}
+
+NetPacketStartEventAck::~NetPacketStartEventAck()
+{
+}
+
+boost::shared_ptr<NetPacket>
+NetPacketStartEventAck::Clone() const
+{
+	boost::shared_ptr<NetPacket> newPacket(new NetPacketStartEventAck);
+	try
+	{
+		newPacket->SetRawData(GetRawData());
+	} catch (const NetException &)
+	{
+		// Need to return the new packet anyway.
+	}
+	return newPacket;
+}
+
+const NetPacketStartEventAck *
+NetPacketStartEventAck::ToNetPacketStartEventAck() const
+{
+	return this;
+}
+
+void
+NetPacketStartEventAck::InternalCheck(const NetPacketHeader*) const
+{
+	// Nothing to do.
+}
+
+//-----------------------------------------------------------------------------
+
 NetPacketGameStart::NetPacketGameStart()
 : NetPacket(NET_TYPE_GAME_START, sizeof(NetPacketGameStartData), MAX_PACKET_SIZE)
 {
diff --git a/src/net/common/servergamestate.cpp b/src/net/common/servergamestate.cpp
index 71f80587..d14aea79 100644
--- a/src/net/common/servergamestate.cpp
+++ b/src/net/common/servergamestate.cpp
@@ -46,6 +46,7 @@ using namespace std;
 #define SERVER_SHOW_CARDS_DELAY_SEC				2
 #define SERVER_PLAYER_TIMEOUT_ADD_DELAY_SEC		2
 #define SERVER_COMPUTER_ACTION_DELAY_SEC		2
+#define SERVER_START_GAME_TIMEOUT_SEC			10
 
 #define SERVER_COMPUTER_PLAYER_NAME				"Computer"
 
@@ -286,35 +287,41 @@ ServerGameStateInit::HandleNewSession(ServerGameThread &server, SessionWrapper s
 int
 ServerGameStateInit::InternalProcess(ServerGameThread &server, SessionWrapper session, boost::shared_ptr<NetPacket> packet)
 {
-	int retVal = MSG_SOCK_INIT_DONE;
+	int retVal = MSG_SOCK_INTERNAL_PENDING;
 
 	if (packet->ToNetPacketStartEvent())
 	{
-		NetPacketStartEvent::Data startData;
-		packet->ToNetPacketStartEvent()->GetData(startData);
-
-		server.ResetComputerPlayerList();
-
-		if (startData.fillUpWithCpuPlayers)
+		// Only admins are allowed to start the game.
+		if (session.playerData->GetRights() == PLAYER_RIGHTS_ADMIN)
 		{
-			int remainingSlots = server.GetGameData().maxNumberOfPlayers - server.GetCurNumberOfPlayers();
-			for (int i = 1; i <= remainingSlots; i++)
+			NetPacketStartEvent::Data startData;
+			packet->ToNetPacketStartEvent()->GetData(startData);
+
+			// Fill up with computer players.
+			server.ResetComputerPlayerList();
+
+			if (startData.fillUpWithCpuPlayers)
 			{
-				boost::shared_ptr<PlayerData> tmpPlayerData(
-					new PlayerData(server.GetLobbyThread().GetNextUniquePlayerId(), 0, PLAYER_TYPE_COMPUTER, PLAYER_RIGHTS_NORMAL));
+				int remainingSlots = server.GetGameData().maxNumberOfPlayers - server.GetCurNumberOfPlayers();
+				for (int i = 1; i <= remainingSlots; i++)
+				{
+					boost::shared_ptr<PlayerData> tmpPlayerData(
+						new PlayerData(server.GetLobbyThread().GetNextUniquePlayerId(), 0, PLAYER_TYPE_COMPUTER, PLAYER_RIGHTS_NORMAL));
 
-				ostringstream name;
-				name << SERVER_COMPUTER_PLAYER_NAME << i;
-				tmpPlayerData->SetName(name.str());
-				server.AddComputerPlayer(tmpPlayerData);
+					ostringstream name;
+					name << SERVER_COMPUTER_PLAYER_NAME << i;
+					tmpPlayerData->SetName(name.str());
+					server.AddComputerPlayer(tmpPlayerData);
 
-				// Send "Player Joined" to other fully connected clients.
-				server.SendToAllPlayers(CreateNetPacketPlayerJoined(*tmpPlayerData), SessionData::Game);
+					// Send "Player Joined" to other fully connected clients.
+					server.SendToAllPlayers(CreateNetPacketPlayerJoined(*tmpPlayerData), SessionData::Game);
+				}
 			}
-		}
+			// Wait for all players to confirm start of game.
+			server.SendToAllPlayers(boost::shared_ptr<NetPacket>(packet->Clone()), SessionData::Game);
 
-		server.InternalStartGame();
-		server.SetState(SERVER_START_GAME_STATE::Instance());
+			server.SetState(ServerGameStateWaitAck::Instance());
+		}
 	}
 	else if (packet->ToNetPacketKickPlayer())
 	{
@@ -365,6 +372,64 @@ AbstractServerGameStateRunning::HandleNewSession(ServerGameThread &server, Sessi
 
 //-----------------------------------------------------------------------------
 
+boost::thread_specific_ptr<ServerGameStateWaitAck> ServerGameStateWaitAck::Ptr;
+
+ServerGameStateWaitAck &
+ServerGameStateWaitAck::Instance()
+{
+	if (!Ptr.get())
+		Ptr.reset(new ServerGameStateWaitAck);
+
+	return *Ptr;
+}
+
+ServerGameStateWaitAck::ServerGameStateWaitAck()
+{
+}
+
+ServerGameStateWaitAck::~ServerGameStateWaitAck()
+{
+}
+
+int
+ServerGameStateWaitAck::Process(ServerGameThread &server)
+{
+	int retVal;
+
+	if (GetTimer().elapsed().total_seconds() >= SERVER_START_GAME_TIMEOUT_SEC)
+	{
+		// On timeout: start anyway.
+		server.SetState(SERVER_START_GAME_STATE::Instance());
+		retVal = MSG_SOCK_INIT_DONE;
+	}
+	else
+		retVal = AbstractServerGameStateReceiving::Process(server);
+
+	return retVal;
+}
+
+int
+ServerGameStateWaitAck::InternalProcess(ServerGameThread &server, SessionWrapper session, boost::shared_ptr<NetPacket> packet)
+{
+	int retVal = MSG_SOCK_INTERNAL_PENDING;
+
+	if (packet->ToNetPacketStartEventAck())
+	{
+		session.sessionData->SetReadyFlag();
+		if (server.GetSessionManager().CountReadySessions() == server.GetSessionManager().GetRawSessionCount())
+		{
+			// Everyone is ready.
+			server.SetState(SERVER_START_GAME_STATE::Instance());
+			retVal = MSG_SOCK_INIT_DONE;
+		}
+		retVal = MSG_SOCK_INIT_DONE;
+	}
+
+	return retVal;
+}
+
+//-----------------------------------------------------------------------------
+
 boost::thread_specific_ptr<ServerGameStateStartGame> ServerGameStateStartGame::Ptr;
 
 ServerGameStateStartGame &
@@ -387,6 +452,8 @@ ServerGameStateStartGame::~ServerGameStateStartGame()
 int
 ServerGameStateStartGame::Process(ServerGameThread &server)
 {
+	server.InternalStartGame();
+
 	boost::shared_ptr<NetPacket> answer(new NetPacketGameStart);
 
 	NetPacketGameStart::Data gameStartData;
diff --git a/src/net/common/servergamethread.cpp b/src/net/common/servergamethread.cpp
index 5dffd923..9d8b7a4d 100644
--- a/src/net/common/servergamethread.cpp
+++ b/src/net/common/servergamethread.cpp
@@ -152,6 +152,7 @@ ServerGameThread::Main()
 	GetSender().SignalTermination();
 	GetSender().Join(SENDER_THREAD_TERMINATE_TIMEOUT);
 
+	ResetComputerPlayerList();
 	GetLobbyThread().RemoveGame(GetId());
 }
 
@@ -273,14 +274,27 @@ ServerGameThread::IsRunning() const
 void
 ServerGameThread::AddComputerPlayer(boost::shared_ptr<PlayerData> player)
 {
-	boost::mutex::scoped_lock lock(m_computerPlayerListMutex);
-	m_computerPlayerList.push_back(player);
+	{
+		boost::mutex::scoped_lock lock(m_computerPlayerListMutex);
+		m_computerPlayerList.push_back(player);
+	}
+	GetLobbyThread().AddComputerPlayer(player);
 }
 
 void
 ServerGameThread::ResetComputerPlayerList()
 {
 	boost::mutex::scoped_lock lock(m_computerPlayerListMutex);
+
+	PlayerDataList::iterator i = m_computerPlayerList.begin();
+	PlayerDataList::iterator end = m_computerPlayerList.end();
+
+	while (i != end)
+	{
+		GetLobbyThread().RemoveComputerPlayer(*i);
+		++i;
+	}
+
 	m_computerPlayerList.clear();
 }
 
diff --git a/src/net/common/serverlobbythread.cpp b/src/net/common/serverlobbythread.cpp
index fa6cba39..66da09c1 100644
--- a/src/net/common/serverlobbythread.cpp
+++ b/src/net/common/serverlobbythread.cpp
@@ -176,6 +176,20 @@ ServerLobbyThread::HandleGameRetrieveAvatar(SessionWrapper session, const NetPac
 	HandleNetPacketRetrieveAvatar(session, tmpPacket);
 }
 
+void
+ServerLobbyThread::AddComputerPlayer(boost::shared_ptr<PlayerData> player)
+{
+	boost::mutex::scoped_lock lock(m_computerPlayersMutex);
+	m_computerPlayers.insert(PlayerDataMap::value_type(player->GetUniqueId(), player));
+}
+
+void
+ServerLobbyThread::RemoveComputerPlayer(boost::shared_ptr<PlayerData> player)
+{
+	boost::mutex::scoped_lock lock(m_computerPlayersMutex);
+	m_computerPlayers.erase(player->GetUniqueId());
+}
+
 void
 ServerLobbyThread::RemoveGame(unsigned id)
 {
@@ -446,6 +460,13 @@ ServerLobbyThread::HandleNetPacketRetrievePlayerInfo(SessionWrapper session, con
 	boost::shared_ptr<PlayerData> tmpPlayer = m_sessionManager.GetSessionByUniquePlayerId(request.playerId).playerData;
 	if (!tmpPlayer.get())
 		tmpPlayer = m_gameSessionManager.GetSessionByUniquePlayerId(request.playerId).playerData;
+	if (!tmpPlayer.get())
+	{
+		boost::mutex::scoped_lock lock(m_computerPlayersMutex);
+		PlayerDataMap::const_iterator pos = m_computerPlayers.find(request.playerId);
+		if (pos != m_computerPlayers.end())
+			tmpPlayer = pos->second;
+	}
 
 	if (tmpPlayer.get())
 	{
diff --git a/src/net/common/sessiondata.cpp b/src/net/common/sessiondata.cpp
index 36fd4553..d761926d 100644
--- a/src/net/common/sessiondata.cpp
+++ b/src/net/common/sessiondata.cpp
@@ -20,7 +20,7 @@
 #include <net/sessiondata.h>
 
 SessionData::SessionData(SOCKET sockfd, unsigned id)
-: m_sockfd(sockfd), m_id(id), m_state(SessionData::Init)
+: m_sockfd(sockfd), m_id(id), m_state(SessionData::Init), m_readyFlag(false)
 {
 }
 
@@ -58,6 +58,27 @@ SessionData::GetSocket() const
 	return m_sockfd;
 }
 
+void
+SessionData::SetReadyFlag()
+{
+	boost::mutex::scoped_lock lock(m_dataMutex);
+	m_readyFlag = true;
+}
+
+void
+SessionData::ResetReadyFlag()
+{
+	boost::mutex::scoped_lock lock(m_dataMutex);
+	m_readyFlag = false;
+}
+
+bool
+SessionData::IsReady() const
+{
+	boost::mutex::scoped_lock lock(m_dataMutex);
+	return m_readyFlag;
+}
+
 const std::string &
 SessionData::GetClientAddr() const
 {
diff --git a/src/net/common/sessionmanager.cpp b/src/net/common/sessionmanager.cpp
index 33f70420..19e0d7a5 100644
--- a/src/net/common/sessionmanager.cpp
+++ b/src/net/common/sessionmanager.cpp
@@ -292,6 +292,24 @@ SessionManager::ForEach(boost::function<void (SessionWrapper)> func)
 	}
 }
 
+unsigned
+SessionManager::CountReadySessions() const
+{
+	unsigned counter = 0;
+	boost::mutex::scoped_lock lock(m_sessionMapMutex);
+
+	SessionMap::const_iterator i = m_sessionMap.begin();
+	SessionMap::const_iterator end = m_sessionMap.end();
+
+	while (i != end)
+	{
+		if ((*i).second.sessionData->IsReady())
+			++counter;
+		++i;
+	}
+	return counter;
+}
+
 void
 SessionManager::Clear()
 {
diff --git a/src/net/netpacket.h b/src/net/netpacket.h
index 79fdf14d..189d7d01 100644
--- a/src/net/netpacket.h
+++ b/src/net/netpacket.h
@@ -68,6 +68,7 @@ class NetPacketGameAdminChanged;
 class NetPacketKickPlayer;
 class NetPacketLeaveCurrentGame;
 class NetPacketStartEvent;
+class NetPacketStartEventAck;
 class NetPacketGameStart;
 class NetPacketHandStart;
 class NetPacketPlayersTurn;
@@ -125,6 +126,7 @@ public:
 	virtual const NetPacketKickPlayer *ToNetPacketKickPlayer() const;
 	virtual const NetPacketLeaveCurrentGame *ToNetPacketLeaveCurrentGame() const;
 	virtual const NetPacketStartEvent *ToNetPacketStartEvent() const;
+	virtual const NetPacketStartEventAck *ToNetPacketStartEventAck() const;
 	virtual const NetPacketGameStart *ToNetPacketGameStart() const;
 	virtual const NetPacketHandStart *ToNetPacketHandStart() const;
 	virtual const NetPacketPlayersTurn *ToNetPacketPlayersTurn() const;
@@ -681,6 +683,22 @@ protected:
 	virtual void InternalCheck(const NetPacketHeader* data) const;
 };
 
+class NetPacketStartEventAck : public NetPacket
+{
+public:
+
+	NetPacketStartEventAck();
+	virtual ~NetPacketStartEventAck();
+
+	virtual boost::shared_ptr<NetPacket> Clone() const;
+
+	virtual const NetPacketStartEventAck *ToNetPacketStartEventAck() const;
+
+protected:
+
+	virtual void InternalCheck(const NetPacketHeader* data) const;
+};
+
 class NetPacketGameStart : public NetPacket
 {
 public:
diff --git a/src/net/servergamestate.h b/src/net/servergamestate.h
index 43e7f85a..4d40b8fa 100644
--- a/src/net/servergamestate.h
+++ b/src/net/servergamestate.h
@@ -129,6 +129,30 @@ private:
 	static boost::thread_specific_ptr<ServerGameStateInit>	Ptr;
 };
 
+// Wait for Ack of start event.
+class ServerGameStateWaitAck : public AbstractServerGameStateReceiving, public AbstractServerGameStateRunning, public AbstractServerGameStateTimer
+{
+public:
+	// Access the state singleton.
+	static ServerGameStateWaitAck &Instance();
+
+	virtual ~ServerGameStateWaitAck();
+
+	// Timeout if waiting takes too long.
+	virtual int Process(ServerGameThread &server);
+
+protected:
+
+	// Protected constructor - this is a singleton.
+	ServerGameStateWaitAck();
+
+	virtual int InternalProcess(ServerGameThread &server, SessionWrapper session, boost::shared_ptr<NetPacket> packet);
+
+private:
+
+	static boost::thread_specific_ptr<ServerGameStateWaitAck>	Ptr;
+};
+
 // State: Start server game.
 class ServerGameStateStartGame : public AbstractServerGameStateRunning
 {
diff --git a/src/net/servergamethread.h b/src/net/servergamethread.h
index ea4807e2..c97ba7b9 100644
--- a/src/net/servergamethread.h
+++ b/src/net/servergamethread.h
@@ -143,6 +143,7 @@ private:
 friend class AbstractServerGameStateReceiving;
 friend class AbstractServerGameStateRunning;
 friend class ServerGameStateInit;
+friend class ServerGameStateWaitAck;
 friend class ServerGameStateStartGame;
 friend class ServerGameStateStartHand;
 friend class ServerGameStateStartRound;
diff --git a/src/net/serverlobbythread.h b/src/net/serverlobbythread.h
index 7221b943..cb9b612b 100644
--- a/src/net/serverlobbythread.h
+++ b/src/net/serverlobbythread.h
@@ -63,6 +63,9 @@ public:
 	void HandleGameRetrievePlayerInfo(SessionWrapper session, const NetPacketRetrievePlayerInfo &tmpPacket);
 	void HandleGameRetrieveAvatar(SessionWrapper session, const NetPacketRetrieveAvatar &tmpPacket);
 
+	void AddComputerPlayer(boost::shared_ptr<PlayerData> player);
+	void RemoveComputerPlayer(boost::shared_ptr<PlayerData> player);
+
 	void RemoveGame(unsigned id);
 
 	u_int32_t GetNextUniquePlayerId();
@@ -145,6 +148,9 @@ private:
 	RemoveGameList m_removeGameList;
 	mutable boost::mutex m_removeGameListMutex;
 
+	PlayerDataMap m_computerPlayers;
+	mutable boost::mutex m_computerPlayersMutex;
+
 	GameMap m_gameMap;
 
 	std::auto_ptr<ReceiverHelper> m_receiver;
diff --git a/src/net/sessiondata.h b/src/net/sessiondata.h
index 72ce06f5..9a1400da 100644
--- a/src/net/sessiondata.h
+++ b/src/net/sessiondata.h
@@ -42,6 +42,10 @@ public:
 
 	SOCKET GetSocket() const;
 
+	void SetReadyFlag();
+	void ResetReadyFlag();
+	bool IsReady() const;
+
 	const std::string &GetClientAddr() const;
 	void SetClientAddr(const std::string &addr);
 
@@ -53,6 +57,7 @@ private:
 	State							m_state;
 	std::string						m_clientAddr;
 	ReceiveBuffer					m_receiveBuffer;
+	bool							m_readyFlag;
 
 	mutable boost::mutex			m_dataMutex;
 };
diff --git a/src/net/sessionmanager.h b/src/net/sessionmanager.h
index 7fda762f..ab6bcfeb 100644
--- a/src/net/sessionmanager.h
+++ b/src/net/sessionmanager.h
@@ -64,6 +64,7 @@ public:
 	bool IsPlayerConnected(unsigned uniqueId) const;
 
 	void ForEach(boost::function<void (SessionWrapper)> func);
+	unsigned CountReadySessions() const;
 
 	void Clear();
 	unsigned GetRawSessionCount();
diff --git a/src/net/socket_msg.h b/src/net/socket_msg.h
index 8b8542e1..0674cd6f 100644
--- a/src/net/socket_msg.h
+++ b/src/net/socket_msg.h
@@ -61,6 +61,7 @@
 #define ERR_NET_BUF_INVALID_SIZE		117
 #define ERR_NET_INVALID_REQUEST_ID		118
 #define ERR_NET_WRONG_AVATAR_SIZE		119
+#define ERR_NET_START_TIMEOUT			120
 
 #define ERR_IRC_INTERNAL				151
 #define ERR_IRC_CONNECT_FAILED			152