diff --git a/public/static/js/game.js b/public/static/js/game.js
index 8d73f7f..1f16f4a 100644
--- a/public/static/js/game.js
+++ b/public/static/js/game.js
@@ -231,17 +231,6 @@ const GameType = Object.freeze({ 'SINGLE': 0, 'MULTI': 1, 'CHALLENGE': 2 });
 
         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 = Game.getGameIdentifier() + '/prepare.json';
@@ -618,7 +607,7 @@ const GameType = Object.freeze({ 'SINGLE': 0, 'MULTI': 1, 'CHALLENGE': 2 });
                     break;
 
                 case 'anonymous_user':
-                    MapGuesser.showModalWithContent('Error', 'You have to login to join a challenge!');
+                    MapGuesser.showModalWithContent('Error', 'You have to login to join this game!');
                     break;
 
                 default:
diff --git a/public/static/js/maps.js b/public/static/js/maps.js
index d8f7a9f..f027b26 100644
--- a/public/static/js/maps.js
+++ b/public/static/js/maps.js
@@ -131,11 +131,13 @@
         }, formData);
     };
 
-    document.getElementById('multiButton').onclick = function () {
-        MapGuesser.showModal('multi');
-        document.getElementById('createNewRoomButton').href = '/multiGame/new/' + this.dataset.mapId;
-        document.getElementById('multiForm').elements.roomId.select();
-        document.getElementById('playMode').style.visibility = 'hidden';
+    if (document.getElementById('multiButton')) {
+        document.getElementById('multiButton').onclick = function () {
+            MapGuesser.showModal('multi');
+            document.getElementById('createNewRoomButton').href = '/multiGame/new/' + this.dataset.mapId;
+            document.getElementById('multiForm').elements.roomId.select();
+            document.getElementById('playMode').style.visibility = 'hidden';
+        }
     }
 
     if (document.getElementById('challengeButton')) {
diff --git a/src/Controller/GameController.php b/src/Controller/GameController.php
index ef3fd5f..7fec2f5 100644
--- a/src/Controller/GameController.php
+++ b/src/Controller/GameController.php
@@ -190,13 +190,17 @@ class GameController implements IAuthenticationRequired
 
     public function prepareMultiGame(): IContent
     {
-        $roomId = \Container::$request->query('roomId');
-        $userName = \Container::$request->post('userName');
-        if (empty($userName)) {
-            $faker = Factory::create();
-            $userName = $faker->userName;
+        /**
+         * @var User $user
+         */
+        $user = \Container::$request->user();
+        if ($user === null)
+        {
+            return new JsonContent(['error' => 'anonymous_user']);
         }
 
+        $roomId = \Container::$request->query('roomId');
+
         $room = $this->multiRoomRepository->getByRoomId($roomId);
 
         if (!isset($room)) {
@@ -225,7 +229,7 @@ class GameController implements IAuthenticationRequired
         $this->multiConnector->sendMessage('join_room', [
             'roomId' => $roomId,
             'token' => $token,
-            'userName' => $userName
+            'userName' => $user->getDisplayName()
         ]);
 
         return new JsonContent([
diff --git a/views/maps.php b/views/maps.php
index 8f5e2d4..d1256bd 100644
--- a/views/maps.php
+++ b/views/maps.php
@@ -9,9 +9,9 @@ TODO: condition!
 <div id="playMode" class="modal">
     <h2>Play map</h2>
     <a id="singleButton" class="button fullWidth marginTop" href="" title="Single player">Single player</a>
-    <p class="bold center marginTop marginBottom">OR</p>
-    <button id="multiButton" class="fullWidth green" data-map-id="">Multiplayer (beta)</button>
     <?php if ($isLoggedIn): ?>
+        <p class="bold center marginTop marginBottom">OR</p>
+        <button id="multiButton" class="fullWidth green" data-map-id="">Multiplayer (beta)</button>
         <p class="bold center marginTop marginBottom">OR</p>
         <button id="challengeButton" class="fullWidth yellow" data-map-id="" data-timer="">Challenge (gamma)</button>
     <?php endif; ?>