diff --git a/public/static/css/game.css b/public/static/css/game.css
index 9887cc7..439676a 100644
--- a/public/static/css/game.css
+++ b/public/static/css/game.css
@@ -102,6 +102,15 @@
     display: none;
 }
 
+#startMultiGameButton {
+    display: none;
+}
+
+#players > p {
+    font-size: 14px;
+    font-weight: bold;
+}
+
 @media screen and (max-width: 599px) {
     #mapName {
         display: none;
diff --git a/public/static/js/game.js b/public/static/js/game.js
index 0cb0616..7f1016f 100644
--- a/public/static/js/game.js
+++ b/public/static/js/game.js
@@ -5,6 +5,8 @@
         NUMBER_OF_ROUNDS: 5,
         MAX_SCORE: 1000,
 
+        mapBounds: null,
+        multi: { token: null, owner: false },
         rounds: [],
         scoreSum: 0,
         panoId: null,
@@ -15,8 +17,190 @@
         adaptGuess: false,
         googleLink: null,
 
-        initialize: function () {
+        MultiConnector: {
+            connection: null,
+            reconnectCounter: 0,
+
+            connect: function () {
+                if (Game.MultiConnector.connection && Game.MultiConnector.connection.readyState !== WebSocket.CLOSED) {
+                    return;
+                }
+
+                Game.MultiConnector.connection = new WebSocket((MapGuesser.isSecure ? 'wss' : 'ws') + '://' + multiUrl);
+
+                Game.MultiConnector.connection.onopen = function () {
+                    document.getElementById('loading').style.visibility = 'hidden';
+
+                    Game.MultiConnector.reconnectCounter = 0;
+
+                    Game.MultiConnector.connection.send(JSON.stringify({ func: 'connect_to_room', args: { roomId: roomId, token: Game.multi.token } }));
+                };
+
+                Game.MultiConnector.connection.onclose = Game.MultiConnector.noConnection;
+
+                Game.MultiConnector.connection.onerror = function (event) {
+                    console.error('WebSocket error in Game.MultiConnector:', event);
+                };
+
+                Game.MultiConnector.connection.onmessage = function (message) {
+                    var json;
+
+                    try {
+                        json = JSON.parse(message.data);
+                    } catch (e) {
+                        console.error('Cannot parse message!');
+                        console.error(message.data);
+                        return;
+                    }
+
+                    switch (json.type) {
+                        case 'initialize':
+                            Game.MultiConnector.initialize(json.data);
+                            break;
+
+                        case 'member_joined':
+                            Game.MultiConnector.memberJoined(json.data);
+                            break;
+
+                        case 'new_round':
+                            Game.MultiConnector.newRound(json.data);
+                            break;
+
+                        case 'results':
+                            //TODO
+                            break;
+
+                        case 'guess':
+                            //TODO
+                            break;
+                    }
+                };
+            },
+
+            noConnection: function () {
+                if (Game.MultiConnector.reconnectCounter === 2) {
+                    console.error('Could not reconnect WebSocket for Game.MultiConnector...')
+                }
+
+                setTimeout(function () {
+                    Game.MultiConnector.reconnectCounter++;
+
+                    console.log('Reconnecting WebSocket for Game.MultiConnector... ' + Game.MultiConnector.reconnectCounter);
+                    Game.MultiConnector.connect();
+                }, 1000 + Math.min(Game.MultiConnector.reconnectCounter * 500, 9000));
+            },
+
+            initialize: function (data) {
+                if (data.history) {
+                    for (var i = 0; i < data.history.length; ++i) {
+                        var round = data.history[i];
+                        Game.rounds.push({ position: round.position, guessPosition: round.guessPosition, realMarker: null, guessMarker: null, line: null });
+                        Game.addRealGuessPair(round.position, round.guessPosition, true);
+                        Game.scoreSum += round.score;
+                    }
+
+                    document.getElementById('currentRound').innerHTML = String(Game.rounds.length) + '/' + String(Game.NUMBER_OF_ROUNDS);
+                    document.getElementById('currentScoreSum').innerHTML = String(Game.scoreSum) + '/' + String(Game.rounds.length * Game.MAX_SCORE);
+                }
+
+                if (data.place) {
+                    Game.panoId = data.place.panoId;
+                    Game.pov = data.place.pov;
+
+                    document.getElementById('panoCover').style.visibility = 'hidden';
+                    MapGuesser.hideModal();
+
+                    Game.startNewRound();
+                }
+
+                document.getElementById('loading').style.visibility = 'hidden';
+
+                var div = document.getElementById('players');
+
+                for (var i = 0; i < data.members.length; ++i) {
+                    var member = data.members[i];
+
+                    var p = document.createElement('p');
+                    p.innerHTML = member.userName + (member.me ? ' (me)' : '');
+                    div.appendChild(p);
+                }
+            },
+
+            memberJoined: function (data) {
+                var div = document.getElementById('players');
+
+                var p = document.createElement('p');
+                p.innerHTML = data.userName;
+                div.appendChild(p);
+            },
+
+            newRound: function (data) {
+                //TODO: workaround until results are not sent
+                if (Game.adaptGuess) {
+                    document.getElementById('guess').classList.remove('adapt');
+                }
+
+                if (Game.rounds.length === Game.NUMBER_OF_ROUNDS) {
+                    Game.reset();
+                }
+
+                // if player didn't guess - TODO: show everything on a map
+                if (data.result && Game.rounds.length > 0 && !Game.rounds[Game.rounds.length - 1].position) {
+                    Game.rounds[Game.rounds.length - 1].position = data.result.position;
+                    Game.addRealGuessPair(data.result.position, null);
+                }
+
+                Game.panoId = data.place.panoId;
+                Game.pov = data.place.pov;
+
+                MapGuesser.hideModal();
+                Game.resetRound();
+                Game.startNewRound();
+            }
+        },
+
+        prepare: function () {
+            var data = new FormData();
+            var userNames;
+
+            if (roomId) {
+                var userNames = localStorage.userNames ? JSON.parse(localStorage.userNames) : {};
+                if (!userNames.hasOwnProperty(roomId)) {
+                    userNames[roomId] = prompt('Your name: ');
+                    localStorage.userNames = JSON.stringify(userNames);
+                }
+
+                data.append('userName', userNames[roomId]);
+            }
+
             document.getElementById('loading').style.visibility = 'visible';
+
+            var url = roomId ? '/multiGame/' + roomId + '/prepare.json' : '/game/' + mapId + '/prepare.json';
+            MapGuesser.httpRequest('POST', url, function () {
+                document.getElementById('loading').style.visibility = 'hidden';
+
+                document.getElementById('mapName').innerHTML = this.response.mapName;
+                Game.mapBounds = this.response.bounds;
+
+                Game.initialize();
+
+                if (roomId) {
+                    Game.multi.token = this.response.token;
+                    Game.multi.owner = this.response.owner;
+
+                    MapGuesser.showModal('multi');
+                    if (Game.multi.owner) {
+                        document.getElementById('startMultiGameButton').style.display = 'block';
+                    }
+
+                    document.getElementById('loading').style.visibility = 'visible';
+
+                    Game.MultiConnector.connect();
+                }
+            }, data);
+        },
+
+        initialize: function () {
             document.getElementById('panoCover').style.visibility = 'visible';
             document.getElementById('currentRound').innerHTML = '1/' + String(Game.NUMBER_OF_ROUNDS);
             document.getElementById('currentScoreSum').innerHTML = '0/0';
@@ -24,9 +208,16 @@
             Game.map.setOptions({
                 draggableCursor: 'crosshair'
             });
-            Game.map.fitBounds(mapBounds);
+            Game.map.fitBounds(Game.mapBounds);
 
-            MapGuesser.httpRequest('GET', '/game/' + mapId + '/initialData.json', function () {
+            if (roomId) {
+                // if it is multiplayer mode, data is sent via WS
+                return;
+            }
+
+            document.getElementById('loading').style.visibility = 'visible';
+
+            MapGuesser.httpRequest('POST', '/game/' + mapId + '/initialData.json', function () {
                 document.getElementById('loading').style.visibility = 'hidden';
                 document.getElementById('panoCover').style.visibility = 'hidden';
 
@@ -63,8 +254,10 @@
             for (var i = 0; i < Game.rounds.length; ++i) {
                 var round = Game.rounds[i];
 
-                if (round.realMarker && round.guessMarker && round.line) {
+                if (round.realMarker) {
                     round.realMarker.setMap(null);
+                }
+                if (round.guessMarker) {
                     round.guessMarker.setMap(null);
                     round.line.setMap(null);
                 }
@@ -96,8 +289,10 @@
                 var lastRound = Game.rounds[Game.rounds.length - 1];
 
                 lastRound.realMarker.setVisible(false);
-                lastRound.guessMarker.setVisible(false);
-                lastRound.line.setVisible(false);
+                if (lastRound.guessMarker) {
+                    lastRound.guessMarker.setVisible(false);
+                    lastRound.line.setVisible(false);
+                }
             }
 
             document.getElementById('panoCover').style.visibility = 'hidden';
@@ -108,7 +303,12 @@
             Game.map.setOptions({
                 draggableCursor: 'crosshair'
             });
-            Game.map.fitBounds(mapBounds);
+            Game.map.fitBounds(Game.mapBounds);
+
+            if (roomId) {
+                // if it is multiplayer mode, data is sent via WS
+                return;
+            }
 
             Game.startNewRound();
         },
@@ -124,8 +324,14 @@
         handleErrorResponse: function (error) {
             // for the time being we only handle the "no_session_found" error and reset the game
 
-            MapGuesser.httpRequest('GET', '/game/' + mapId + '/json', function () {
-                mapBounds = this.response.bounds;
+            if (roomId) {
+                //TODO: better error message
+                alert('Your session is invalid, please start multiplayer again!')
+                return;
+            }
+
+            MapGuesser.httpRequest('GET', '/game/' + mapId + '/prepare.json', function () {
+                Game.mapBounds = this.response.bounds;
 
                 Game.reset();
             });
@@ -160,7 +366,8 @@
             data.append('lat', String(guessPosition.lat));
             data.append('lng', String(guessPosition.lng));
 
-            MapGuesser.httpRequest('POST', '/game/' + mapId + '/guess.json', function () {
+            var url = roomId ? '/multiGame/' + roomId + '/guess.json' : '/game/' + mapId + '/guess.json';
+            MapGuesser.httpRequest('POST', url, function () {
                 if (this.response.error) {
                     Game.handleErrorResponse(this.response.error);
                     return;
@@ -204,6 +411,10 @@
                     Game.panoId = this.response.place.panoId;
                     Game.pov = this.response.place.pov;
                 } else {
+                    if (!Game.multi.owner) {
+                        //TODO: "waiting for" disabled button
+                        document.getElementById('continueButton').style.display = 'none';
+                    }
                     Game.panoId = null;
                     Game.pov = null;
                 }
@@ -233,6 +444,10 @@
                 window.open('https://www.google.com/maps/search/?api=1&query=' + this.getPosition().toUrlValue(), '_blank');
             });
 
+            if (!guessPosition) {
+                return;
+            }
+
             round.guessMarker = new google.maps.Marker({
                 map: Game.map,
                 visible: !hidden,
@@ -304,7 +519,10 @@
             scoreInfo.children[0].style.display = 'none';
             scoreInfo.children[1].style.display = 'block';
             document.getElementById('showSummaryButton').style.display = null;
-            document.getElementById('startNewGameButton').style.display = 'block';
+
+            if (Game.multi.owner) {
+                document.getElementById('startNewGameButton').style.display = 'block';
+            }
 
             var resultBounds = new google.maps.LatLngBounds();
 
@@ -325,12 +543,17 @@
                     fontWeight: '500',
                     text: String(i + 1)
                 });
+
                 round.realMarker.setVisible(true);
-                round.guessMarker.setVisible(true);
-                round.line.setVisible(true);
+                if (round.guessMarker) {
+                    round.guessMarker.setVisible(true);
+                    round.line.setVisible(true);
+                }
 
                 resultBounds.extend(round.position);
-                resultBounds.extend(round.guessPosition);
+                if (round.guessMarker) {
+                    resultBounds.extend(round.guessPosition);
+                }
             }
 
             Game.map.fitBounds(resultBounds);
@@ -378,13 +601,7 @@
         }
     };
 
-    MapGuesser.sessionAvailableHooks.reinitializeGame = function () {
-        MapGuesser.httpRequest('GET', '/game/' + mapId + '/json', function () {
-            mapBounds = this.response.bounds;
-
-            Game.initialize();
-        });
-    };
+    MapGuesser.sessionAvailableHooks.reinitializeGame = Game.prepare;
 
     if (!('ontouchstart' in document.documentElement)) {
         Game.adaptGuess = true;
@@ -445,7 +662,9 @@
         Game.rewriteGoogleLink();
     });
 
-    Game.initialize();
+    if (COOKIES_CONSENT) {
+        Game.prepare();
+    }
 
     document.getElementById('showGuessButton').onclick = function () {
         this.style.visibility = 'hidden';
@@ -462,7 +681,19 @@
     }
 
     document.getElementById('continueButton').onclick = function () {
-        Game.resetRound();
+        if (roomId) {
+            if (!Game.multi.owner) {
+                return;
+            }
+
+            document.getElementById('loading').style.visibility = 'visible';
+
+            MapGuesser.httpRequest('POST', '/multiGame/' + roomId + '/nextRound.json', function () {
+                document.getElementById('loading').style.visibility = 'hidden';
+            });
+        } else {
+            Game.resetRound();
+        }
     }
 
     document.getElementById('showSummaryButton').onclick = function () {
@@ -470,6 +701,31 @@
     }
 
     document.getElementById('startNewGameButton').onclick = function () {
-        Game.reset();
+        if (roomId) {
+            if (!Game.multi.owner) {
+                return;
+            }
+
+            document.getElementById('loading').style.visibility = 'visible';
+
+            MapGuesser.httpRequest('POST', '/multiGame/' + roomId + '/initialData.json', function () {
+                document.getElementById('loading').style.visibility = 'hidden';
+            });
+        } else {
+            Game.reset();
+        }
+    }
+
+    document.getElementById('startMultiGameButton').onclick = function () {
+        if (!roomId || !Game.multi.owner) {
+            return;
+        }
+
+        MapGuesser.hideModal();
+        document.getElementById('loading').style.visibility = 'visible';
+
+        MapGuesser.httpRequest('POST', '/multiGame/' + roomId + '/initialData.json', function () {
+            document.getElementById('loading').style.visibility = 'hidden';
+        });
     }
 })();
diff --git a/public/static/js/mapguesser.js b/public/static/js/mapguesser.js
index 8af9ffe..89a79a9 100644
--- a/public/static/js/mapguesser.js
+++ b/public/static/js/mapguesser.js
@@ -1,4 +1,5 @@
 var MapGuesser = {
+    isSecure: window.location.protocol === 'https:',
     cookiesAgreed: false,
     sessionAvailableHooks: {},
 
diff --git a/views/game.php b/views/game.php
index c772f29..10acef6 100644
--- a/views/game.php
+++ b/views/game.php
@@ -5,10 +5,19 @@
 
 @extends(templates/layout_full)
 
+@section(pagemodal)
+<div id="multi" class="modal">
+    <h2>Multiplayer (beta)</h2>
+    <p class="marginTop">Waiting for players...</p>
+    <div id="players" class="marginTop"></div>
+    <button id="startMultiGameButton" class="button fullWidth marginTop green">Start game</button>
+</div>
+@endsection
+
 @section(subheader)
-        <span id="mapName" class="bold"><?= $mapName ?></span><!--
-        --><span>Round <span id="currentRound" class="bold"></span></span><!--
-        --><span>Score <span id="currentScoreSum" class="bold"></span></span>
+    <span id="mapName" class="bold"></span><!--
+ --><span>Round <span id="currentRound" class="bold"></span></span><!--
+ --><span>Score <span id="currentScoreSum" class="bold"></span></span>
 @endsection
 
 @section(main)
@@ -50,7 +59,8 @@
 
 @section(pageScript)
 <script>
-    var mapId = <?= $mapId ?>;
-    var mapBounds = <?= json_encode($bounds) ?>;
+    var multiUrl = '<?= $_ENV['MULTI_WS_HOST'] . ':' . $_ENV['MULTI_WS_PORT'] ?>';
+    var roomId = <?= isset($roomId) ? '\'' . $roomId . '\'' : 'null' ?>;
+    var mapId = <?= isset($mapId) ? '\'' . $mapId . '\'' : 'null' ?>;
 </script>
 @endsection