Campaign mode can't be voted for. The host has to manually create/select the campaign save, so switching to the campaign mode when the host isn't present would cause problems.

Barotrauma/BarotraumaClient/Source/Networking/Voting.cs

@@ -38,6 +38,15 @@ namespace Barotrauma
                 allowModeVoting = value;
                 GameMain.NetLobbyScreen.ModeList.Enabled = value || GameMain.Server != null;
                 GameMain.NetLobbyScreen.InfoFrame.FindChild("modevotes", true).Visible = value;
+
+                //gray out modes that can't be voted
+                foreach (GUITextBlock comp in GameMain.NetLobbyScreen.ModeList.children)
+                {
+                    comp.TextColor =
+                        new Color(comp.TextColor.R, comp.TextColor.G, comp.TextColor.B, 
+                            !allowModeVoting || ((GameModePreset)comp.UserData).Votable ? (byte)255 : (byte)100);
+                }
+
                 if (GameMain.Server != null)
                 {
                     UpdateVoteTexts(value ? GameMain.Server.ConnectedClients : null, VoteType.Mode);
@@ -56,7 +65,7 @@ namespace Barotrauma
             GUIListBox listBox = (voteType == VoteType.Sub) ?
                 GameMain.NetLobbyScreen.SubList : GameMain.NetLobbyScreen.ModeList;
 
-            foreach (GUIComponent comp in listBox.children)
+            foreach (GUITextBlock comp in listBox.children)
             {
                 GUITextBlock voteText = comp.FindChild("votes") as GUITextBlock;
                 if (voteText != null) comp.RemoveChild(voteText);

Barotrauma/BarotraumaClient/Source/Screens/NetLobbyScreen.cs

@@ -763,6 +763,8 @@ namespace Barotrauma
             else if (component.Parent == GameMain.NetLobbyScreen.ModeList)
             {
                 if (!GameMain.Client.Voting.AllowModeVoting) return false;
+                if (!((GameModePreset)userData).Votable) return false;
+
                 voteType = VoteType.Mode;
             }
             else

Barotrauma/BarotraumaShared/Source/GameSession/GameModes/GameMode.cs

@@ -8,13 +8,9 @@ namespace Barotrauma
         public static List<GameModePreset> PresetList = new List<GameModePreset>();
 
         protected DateTime startTime;
-
-        //public readonly bool IsSinglePlayer;
-
+        
         protected bool isRunning;
-
-        //protected string name;
-
+        
         protected GameModePreset preset;
 
         private string endMessage;
@@ -57,13 +53,6 @@ namespace Barotrauma
         public virtual void Start()
         {
             startTime = DateTime.Now;
-            //if (duration!=TimeSpan.Zero)
-            //{
-            //    endTime = startTime + duration;
-            //    this.duration = duration;
-
-            //    timerBar = new GUIProgressBar(new Rectangle(GameMain.GraphicsWidth - 120, 20, 100, 25), Color.Gold, 0.0f, null);  
-            //}
 
             endMessage = "The round has ended!";
 
@@ -74,20 +63,7 @@ namespace Barotrauma
 
         public virtual void AddToGUIUpdateList() { }
 
-        public virtual void Update(float deltaTime)
-        {
-            //if (!isRunning) return;
-
-            //if (duration != TimeSpan.Zero)
-            //{
-            //    double elapsedTime = (DateTime.Now - startTime).TotalSeconds;
-            //    timerBar.BarSize = (float)(elapsedTime / duration.TotalSeconds);
-            //}
-            //if (DateTime.Now >= endTime)
-            //{
-            //    End(endMessage);                
-            //}
-        }
+        public virtual void Update(float deltaTime) { }
 
         public virtual void End(string endMessage = "")
         {

Barotrauma/BarotraumaShared/Source/GameSession/GameModes/GameModePreset.cs

@@ -10,17 +10,34 @@ namespace Barotrauma
 
         public ConstructorInfo Constructor;
         public string Name;
-        public bool IsSinglePlayer;
 
-        public string Description;
+        public bool IsSinglePlayer
+        {
+            get;
+            private set;
+        }
 
-        public GameModePreset(string name, Type type, bool isSinglePlayer = false)
+        //are clients allowed to vote for this gamemode
+        public bool Votable
+        {
+            get;
+            private set;
+        }
+
+        public string Description
+        {
+            get;
+            private set;
+        }
+
+        public GameModePreset(string name, Type type, bool isSinglePlayer = false, bool votable = true)
         {
             this.Name = name;
 
             Constructor = type.GetConstructor(new Type[] { typeof(GameModePreset), typeof(object) });
 
             IsSinglePlayer = isSinglePlayer;
+            Votable = votable;
 
             list.Add(this);
         }
@@ -46,7 +63,7 @@ namespace Barotrauma
                 + "an alien artifact or killing a creature that's terrorizing nearby outposts. The game ends "
                 + "when the task is completed or everyone in the crew has died.";
 
-            new GameModePreset("Campaign", typeof(MultiplayerCampaign), false);
+            new GameModePreset("Campaign", typeof(MultiplayerCampaign), false, false);
         }
     }
 }

Barotrauma/BarotraumaShared/Source/Networking/Voting.cs

@@ -103,6 +103,8 @@ namespace Barotrauma
                 case VoteType.Mode:
                     string modeName = inc.ReadString();
                     GameModePreset mode = GameModePreset.list.Find(gm => gm.Name == modeName);
+                    if (!mode.Votable) break;
+
                     sender.SetVote(voteType, mode);
 #if CLIENT
                     UpdateVoteTexts(GameMain.Server.ConnectedClients, voteType);