diff --git a/DXMainClient/DXGUI/Multiplayer/GameLobby/GameLobbyBase.cs b/DXMainClient/DXGUI/Multiplayer/GameLobby/GameLobbyBase.cs
index 169f9b95d..9d24a8e1e 100644
--- a/DXMainClient/DXGUI/Multiplayer/GameLobby/GameLobbyBase.cs
+++ b/DXMainClient/DXGUI/Multiplayer/GameLobby/GameLobbyBase.cs
@@ -1068,11 +1068,12 @@ protected GameModeMapFilter GetDefaultGameModeMapFilter()
 
         /// <summary>
         /// Applies disallowed side indexes to the side option drop-downs
-        /// and player options.
+        /// and player options for human or computer players.
         /// </summary>
-        protected void CheckDisallowedSides()
+        protected void CheckDisallowedSidesForGroup(bool forHumanPlayers)
         {
-            var disallowedSideArray = GetDisallowedSides();
+            var disallowedSideArray = GetDisallowedSidesForGroup(forHumanPlayers);
+            var playerInfos = forHumanPlayers ? Players : AIPlayers;
             int defaultSide = 0;
             int allowedSideCount = disallowedSideArray.Count(b => b == false);
 
@@ -1086,28 +1087,25 @@ protected void CheckDisallowedSides()
                         defaultSide = i + RandomSelectorCount;
                 }
 
-                foreach (XNADropDown dd in ddPlayerSides)
+                foreach (PlayerInfo pInfo in playerInfos)
                 {
-                    //dd.Items[0].Selectable = false;
+                    var dd = ddPlayerSides[pInfo.Index];
                     for (int i = 0; i < RandomSelectorCount; i++)
                         dd.Items[i].Selectable = false;
                 }
             }
             else
             {
-                foreach (XNADropDown dd in ddPlayerSides)
+                foreach (PlayerInfo pInfo in playerInfos)
                 {
-                    //dd.Items[0].Selectable = true;
+                    var dd = ddPlayerSides[pInfo.Index];
                     for (int i = 0; i < RandomSelectorCount; i++)
                         dd.Items[i].Selectable = true;
                 }
             }
 
-            var concatPlayerList = Players.Concat(AIPlayers);
-
             // Disable custom random groups if all or all except one of included sides are unavailable.
             int c = 0;
-            var playerInfos = concatPlayerList.ToList();
             foreach (int[] randomSides in RandomSelectors)
             {
                 int disableCount = 0;
@@ -1120,11 +1118,11 @@ protected void CheckDisallowedSides()
 
                 bool disabled = disableCount >= randomSides.Length - 1;
 
-                foreach (XNADropDown dd in ddPlayerSides)
-                    dd.Items[1 + c].Selectable = !disabled;
-
                 foreach (PlayerInfo pInfo in playerInfos)
                 {
+                    var dd = ddPlayerSides[pInfo.Index];
+                    dd.Items[1 + c].Selectable = !disabled;
+
                     if (pInfo.SideId == 1 + c && disabled)
                         pInfo.SideId = defaultSide;
                 }
@@ -1140,21 +1138,24 @@ protected void CheckDisallowedSides()
 
                 if (disabled)
                 {
-                    foreach (XNADropDown dd in ddPlayerSides)
-                        dd.Items[i + RandomSelectorCount].Selectable = false;
-
                     // Change the sides of players that use the disabled
                     // side to the default side
                     foreach (PlayerInfo pInfo in playerInfos)
                     {
+                        var dd = ddPlayerSides[pInfo.Index];
+                        dd.Items[i + RandomSelectorCount].Selectable = false;
+
                         if (pInfo.SideId == i + RandomSelectorCount)
                             pInfo.SideId = defaultSide;
                     }
                 }
                 else
                 {
-                    foreach (XNADropDown dd in ddPlayerSides)
+                    foreach (PlayerInfo pInfo in playerInfos)
+                    {
+                        var dd = ddPlayerSides[pInfo.Index];
                         dd.Items[i + RandomSelectorCount].Selectable = true;
+                    }
                 }
             }
 
@@ -1178,22 +1179,51 @@ protected void CheckDisallowedSides()
                         pInfo.SideId = defaultSide;
                 }
 
-                foreach (XNADropDown dd in ddPlayerSides)
+                foreach (PlayerInfo pInfo in playerInfos)
                 {
+                    var dd = ddPlayerSides[pInfo.Index];
                     if (dd.Items.Count > GetSpectatorSideIndex())
                         dd.Items[SideCount + RandomSelectorCount].Selectable = false;
                 }
             }
             else
             {
-                foreach (XNADropDown dd in ddPlayerSides)
+                foreach (PlayerInfo pInfo in playerInfos)
                 {
+                    var dd = ddPlayerSides[pInfo.Index];
                     if (dd.Items.Count > SideCount + RandomSelectorCount)
                         dd.Items[SideCount + RandomSelectorCount].Selectable = true;
                 }
             }
         }
 
+        /// <summary>
+        /// Applies disallowed side indexes to the side option drop-downs
+        /// and player options.
+        /// </summary>
+        protected void CheckDisallowedSides()
+        {
+            CheckDisallowedSidesForGroup(forHumanPlayers:false);
+            CheckDisallowedSidesForGroup(forHumanPlayers:true);
+        }
+
+        /// <summary>
+        /// Gets a list of side indexes that are disallowed for human or computer players.
+        /// </summary>
+        /// <returns>A list of disallowed side indexes.</returns>
+        protected bool[] GetDisallowedSidesForGroup(bool forHumanPlayers)
+        {
+            var returnValue = GetDisallowedSides();
+            var sides = forHumanPlayers ? GameMode?.DisallowedHumanPlayerSides : GameMode?.DisallowedComputerPlayerSides;
+            if (sides != null)
+            {
+                foreach (int i in sides)
+                    returnValue[i] = true;
+            }
+
+            return returnValue;
+        }
+
         /// <summary>
         /// Gets a list of side indexes that are disallowed.
         /// </summary>
@@ -1292,13 +1322,20 @@ protected virtual PlayerHouseInfo[] Randomize(List<TeamStartMapping> teamStartMa
             {
                 PlayerInfo pInfo;
                 PlayerHouseInfo pHouseInfo = houseInfos[i];
+                bool[] disallowedSides;
 
                 if (i < Players.Count)
+                {
                     pInfo = Players[i];
+                    disallowedSides = GetDisallowedSidesForGroup(forHumanPlayers:true);
+                }
                 else
+                {
                     pInfo = AIPlayers[i - Players.Count];
+                    disallowedSides = GetDisallowedSidesForGroup(forHumanPlayers:false);
+                }
 
-                pHouseInfo.RandomizeSide(pInfo, SideCount, random, GetDisallowedSides(), RandomSelectors, RandomSelectorCount);
+                pHouseInfo.RandomizeSide(pInfo, SideCount, random, disallowedSides, RandomSelectors, RandomSelectorCount);
 
                 pHouseInfo.RandomizeColor(pInfo, freeColors, MPColors, random);
                 pHouseInfo.RandomizeStart(pInfo, random, freeStartingLocations, takenStartingLocations, teamStartMappings.Any());
@@ -2058,6 +2095,8 @@ protected virtual void CopyPlayerDataToUI()
             MapPreviewBox.UpdateStartingLocationTexts();
             UpdateMapPreviewBoxEnabledStatus();
 
+            CheckDisallowedSides();
+
             PlayerUpdatingInProgress = false;
         }
 
@@ -2197,8 +2236,6 @@ protected virtual void ChangeMap(GameModeMap gameModeMap)
                     pInfo.TeamId = 0;
             }
 
-            CheckDisallowedSides();
-
 
             if (Map.CoopInfo != null)
             {
diff --git a/DXMainClient/DXGUI/Multiplayer/GameLobby/LANGameLobby.cs b/DXMainClient/DXGUI/Multiplayer/GameLobby/LANGameLobby.cs
index dda7e57d0..574ed73ba 100644
--- a/DXMainClient/DXGUI/Multiplayer/GameLobby/LANGameLobby.cs
+++ b/DXMainClient/DXGUI/Multiplayer/GameLobby/LANGameLobby.cs
@@ -836,6 +836,11 @@ private void HandlePlayerOptionsRequest(string sender, string data)
             if (color < 0 || color > MPColors.Count)
                 return;
 
+            var disallowedSides = GetDisallowedSides();
+
+            if (side > 0 && side <= SideCount && disallowedSides[side - 1])
+                return;
+
             if (Map.CoopInfo != null)
             {
                 if (Map.CoopInfo.DisallowedPlayerSides.Contains(side - 1) || side == SideCount + RandomSelectorCount)
@@ -946,6 +951,7 @@ private void HandlePlayerOptionsBroadcast(string data)
             }
 
             CopyPlayerDataToUI();
+
             localPlayer = FindLocalPlayer();
             if (localPlayer != null && oldSideId != localPlayer.SideId)
                 UpdateDiscordPresence();
diff --git a/DXMainClient/DXGUI/Multiplayer/GameLobby/SkirmishLobby.cs b/DXMainClient/DXGUI/Multiplayer/GameLobby/SkirmishLobby.cs
index d654f8881..e615ef828 100644
--- a/DXMainClient/DXGUI/Multiplayer/GameLobby/SkirmishLobby.cs
+++ b/DXMainClient/DXGUI/Multiplayer/GameLobby/SkirmishLobby.cs
@@ -52,8 +52,6 @@ public override void Initialize()
 
             LoadSettings();
 
-            CheckDisallowedSides();
-
             CopyPlayerDataToUI();
 
             ProgramConstants.PlayerNameChanged += ProgramConstants_PlayerNameChanged;
diff --git a/DXMainClient/Domain/Multiplayer/GameMode.cs b/DXMainClient/Domain/Multiplayer/GameMode.cs
index bad2b5d69..60af545f9 100644
--- a/DXMainClient/Domain/Multiplayer/GameMode.cs
+++ b/DXMainClient/Domain/Multiplayer/GameMode.cs
@@ -60,6 +60,17 @@ public GameMode(string name)
         /// </summary>
         public List<int> DisallowedPlayerSides = new List<int>();
 
+        /// <summary>
+        /// List of side indices human players cannot select in this game mode.
+        /// </summary>
+        public List<int> DisallowedHumanPlayerSides = new List<int>();
+
+        /// <summary>
+        /// List of side indices computer players cannot select in this game mode.
+        /// </summary>
+        public List<int> DisallowedComputerPlayerSides = new List<int>();
+
+
         /// </summary>
         /// Override for minimum amount of players needed to play any map in this game mode.
         /// </summary>
@@ -100,6 +111,20 @@ public void Initialize()
             foreach (string sideIndex in disallowedSides)
                 DisallowedPlayerSides.Add(int.Parse(sideIndex));
 
+            disallowedSides = forcedOptionsIni
+                .GetStringValue(Name, "DisallowedHumanPlayerSides", string.Empty)
+                .Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+
+            foreach (string sideIndex in disallowedSides)
+                DisallowedHumanPlayerSides.Add(int.Parse(sideIndex));
+
+            disallowedSides = forcedOptionsIni
+                .GetStringValue(Name, "DisallowedComputerPlayerSides", string.Empty)
+                .Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+
+            foreach (string sideIndex in disallowedSides)
+                DisallowedComputerPlayerSides.Add(int.Parse(sideIndex));
+
             ParseForcedOptions(forcedOptionsIni);
 
             ParseSpawnIniOptions(forcedOptionsIni);