diff --git a/frontend/src/dialogues/chat/MultiChatDialog.vue b/frontend/src/dialogues/chat/MultiChatDialog.vue
index 6521d1b..d05a35a 100644
--- a/frontend/src/dialogues/chat/MultiChatDialog.vue
+++ b/frontend/src/dialogues/chat/MultiChatDialog.vue
@@ -321,6 +321,8 @@ export default {
             pendingRoomCreateName: '',
             pendingRoomCreateAttempts: 0,
             pendingRoomCreateTimer: null,
+            roomPasswords: {},
+            passwordPromptActive: false,
             // Palette state
             paletteWidth: 420,
             paletteHeight: 220,
@@ -365,7 +367,7 @@ export default {
         selectedRoom(newVal, oldVal) {
             if (newVal && this.transportConnected) {
                 const room = this.getSelectedRoomName();
-                if (room) this.sendWithToken({ type: 'join', room, password: '' });
+                if (room) this.sendWithToken({ type: 'join', room, password: this.getRoomPassword(room) });
                 this.messages = [];
                 this.usersInRoom = [];
                 this.selectedTargetUser = null;
@@ -405,6 +407,43 @@ export default {
         roomNamesEqual(a, b) {
             return (a || '').trim().toLowerCase() === (b || '').trim().toLowerCase();
         },
+        getRoomPassword(roomName) {
+            if (!roomName) return '';
+            return this.roomPasswords[roomName] || '';
+        },
+        async handleRoomPasswordError(errorCode) {
+            const room = this.getSelectedRoomName();
+            if (!room || this.passwordPromptActive) return;
+            this.passwordPromptActive = true;
+            try {
+                const isInvalid = errorCode === 'room_password_invalid';
+                const promptText = isInvalid
+                    ? this.$t('chat.multichat.password.invalidPrompt', { room })
+                    : this.$t('chat.multichat.password.requiredPrompt', { room });
+                const entered = window.prompt(promptText, '');
+                if (entered === null) {
+                    this.messages.push({
+                        id: Date.now(),
+                        user: 'System',
+                        text: this.$t('chat.multichat.password.cancelled', { room })
+                    });
+                    return;
+                }
+                const password = entered.trim();
+                if (!password) {
+                    this.messages.push({
+                        id: Date.now(),
+                        user: 'System',
+                        text: this.$t('chat.multichat.password.empty')
+                    });
+                    return;
+                }
+                this.roomPasswords[room] = password;
+                this.sendWithToken({ type: 'join', room, password });
+            } finally {
+                this.passwordPromptActive = false;
+            }
+        },
         tryConfirmRoomCreateSuccess() {
             if (!this.pendingRoomCreateName) return false;
             const created = this.ownRooms.find((r) => this.roomNamesEqual(r.title, this.pendingRoomCreateName));
@@ -805,7 +844,8 @@ export default {
             // Drop references to losers so GC can collect
             this.pendingWs = [];
                     // Prepare handshake like before
-                    const init = { type: 'init', name: this.user?.username || '', room: this.getSelectedRoomName() || '', password: '' };
+                    const initRoom = this.getSelectedRoomName() || '';
+                    const init = { type: 'init', name: this.user?.username || '', room: initRoom, password: this.getRoomPassword(initRoom) };
                     if (this.debug) console.log('[Chat WS >>]', init);
                     this.wsSend(init);
                     if (this.connectAttemptTimeout) clearTimeout(this.connectAttemptTimeout);
@@ -902,7 +942,8 @@ export default {
                 this.transportConnected = true;
                 const dt = Date.now() - (this.wsStartAt || Date.now());
                 console.log('[Chat WS] open in', dt, 'ms', '| protocol:', ws.protocol || '(none)', '| url:', url);
-                const init = { type: 'init', name: this.user?.username || '', room: this.getSelectedRoomName() || '', password: '' };
+                const initRoom = this.getSelectedRoomName() || '';
+                const init = { type: 'init', name: this.user?.username || '', room: initRoom, password: this.getRoomPassword(initRoom) };
                 if (this.debug) console.log('[Chat WS >>]', init);
                 this.wsSend(init);
                 if (this.connectOpenTimer) { clearTimeout(this.connectOpenTimer); this.connectOpenTimer = null; }
@@ -1413,6 +1454,10 @@ export default {
             if (!obj) return;
             if (obj.type === 'error') {
                 const text = obj.message || 'chat_error';
+                if (text === 'room_password_required' || text === 'room_password_invalid') {
+                    this.handleRoomPasswordError(text);
+                    return;
+                }
                 this.setStatus('error');
                 this.messages.push({ id: Date.now(), user: 'System', text: `Fehler: ${text}` });
                 return;
diff --git a/frontend/src/i18n/locales/de/chat.json b/frontend/src/i18n/locales/de/chat.json
index c473b41..4bc53b9 100644
--- a/frontend/src/i18n/locales/de/chat.json
+++ b/frontend/src/i18n/locales/de/chat.json
@@ -114,6 +114,12 @@
                     "servicesStatus": "Service-Status"
                 },
                 "types": {}
+            },
+            "password": {
+                "requiredPrompt": "Der Raum \"{room}\" ist passwortgeschützt. Bitte Passwort eingeben:",
+                "invalidPrompt": "Falsches Passwort für \"{room}\". Bitte erneut eingeben:",
+                "cancelled": "Beitritt zu \"{room}\" abgebrochen.",
+                "empty": "Passwort darf nicht leer sein."
             }
         },
         "randomchat": {
diff --git a/frontend/src/i18n/locales/en/chat.json b/frontend/src/i18n/locales/en/chat.json
index af063b4..c4a5522 100644
--- a/frontend/src/i18n/locales/en/chat.json
+++ b/frontend/src/i18n/locales/en/chat.json
@@ -114,6 +114,12 @@
                     "servicesStatus": "Service status"
                 },
                 "types": {}
+            },
+            "password": {
+                "requiredPrompt": "Room \"{room}\" is password-protected. Please enter password:",
+                "invalidPrompt": "Wrong password for \"{room}\". Please try again:",
+                "cancelled": "Join to \"{room}\" was cancelled.",
+                "empty": "Password must not be empty."
             }
         },
         "randomchat": {
diff --git a/frontend/src/i18n/locales/es/chat.json b/frontend/src/i18n/locales/es/chat.json
index dc0e951..b91ada0 100644
--- a/frontend/src/i18n/locales/es/chat.json
+++ b/frontend/src/i18n/locales/es/chat.json
@@ -113,6 +113,12 @@
                     "servicesStatus": "Estado de servicios"
                 },
                 "types": {}
+            },
+            "password": {
+                "requiredPrompt": "La sala \"{room}\" está protegida por contraseña. Introduce la contraseña:",
+                "invalidPrompt": "Contraseña incorrecta para \"{room}\". Inténtalo de nuevo:",
+                "cancelled": "Se canceló el acceso a \"{room}\".",
+                "empty": "La contraseña no puede estar vacía."
             }
         },
         "randomchat": {