diff --git a/assets/scripts/lobby/buttonEventListeners2.js b/assets/scripts/lobby/buttonEventListeners2.js
index 06985f283..87389286f 100644
--- a/assets/scripts/lobby/buttonEventListeners2.js
+++ b/assets/scripts/lobby/buttonEventListeners2.js
@@ -185,6 +185,7 @@ $('#createNewRoomButton').on('click', (data) => {
     newRoomPassword: $('#newRoomPassword').val(),
     gameMode: $($('.gameModeSelect')[1]).val(),
     muteSpectators: $('.muteSpectators')[1].checked,
+    rebal9p: $('.rebal9p')[1].checked,
     ranked: $($('.rankedSelect')[1]).val(),
   };
 
@@ -192,6 +193,7 @@ $('#createNewRoomButton').on('click', (data) => {
   $($('.maxNumPlayers')[0]).val(sendObj.maxNumPlayers);
   $($('.gameModeSelect')[0]).val(sendObj.gameMode);
   $('.muteSpectators')[0].checked = sendObj.muteSpectators;
+  $('.rebal9p')[0].checked = sendObj.rebal9p;
   $($('.rankedSelect')[0]).val(sendObj.ranked);
 
   if (inRoom === false) {
diff --git a/assets/scripts/lobby/sockets/sockets.js b/assets/scripts/lobby/sockets/sockets.js
index d47faa1d2..c68dd5cbb 100644
--- a/assets/scripts/lobby/sockets/sockets.js
+++ b/assets/scripts/lobby/sockets/sockets.js
@@ -783,6 +783,13 @@ $('.muteSpectators').on('change', (e) => {
   socket.emit('update-room-muteSpectators', e.target.checked);
 });
 
+$('.rebal9p').on('change', (e) => {
+  $('.rebal9p')[0].checked = e.target.checked;
+  $('.rebal9p')[1].checked = e.target.checked;
+
+  socket.emit('update-room-rebal9p', e.target.checked);
+});
+
 // Update the new room menu with the gameModes available.
 socket.on('leave-room-requested', () => {
   leaveRoom();
diff --git a/src/gameplay/game.ts b/src/gameplay/game.ts
index 4c9e74b20..7419093bc 100644
--- a/src/gameplay/game.ts
+++ b/src/gameplay/game.ts
@@ -46,6 +46,7 @@ function Game(
   gameMode_,
   muteSpectators_,
   ranked_,
+  rebal9p_,
   callback_,
 ) {
   this.callback = callback_;
@@ -177,6 +178,7 @@ function Game(
   this.chatHistory = []; // Here because chatHistory records after game starts
 
   this.muteSpectators = muteSpectators_;
+  this.rebal9p = rebal9p_;
 }
 
 // Game object inherits all the functions and stuff from Room
@@ -398,6 +400,12 @@ Game.prototype.startGame = function (options) {
   }
 
   // Now we initialise roles
+  const alliances = this.alliances.concat();
+  if (this.rebal9p) {
+    // Swap last two elements of alliances array
+    [alliances[8], alliances[9]] = [alliances[9], alliances[8]];
+  }
+
   for (let i = 0; i < this.socketsOfPlayers.length; i++) {
     this.playersInGame[i] = {};
     // assign them the sockets but with shuffled.
@@ -409,7 +417,7 @@ Game.prototype.startGame = function (options) {
 
     // set the role to be from the roles array with index of the value
     // of the rolesAssignment which has been shuffled
-    this.playersInGame[i].alliance = this.alliances[rolesAssignment[i]];
+    this.playersInGame[i].alliance = alliances[rolesAssignment[i]];
 
     this.playerUsernamesInGame.push(
       this.socketsOfPlayers[i].request.user.username,
@@ -1317,6 +1325,12 @@ Game.prototype.finishGame = function (toBeWinner) {
     botUsernames = [];
   }
 
+  let gameMode = this.gameMode;
+
+  if (this.playersInGame.length === 9 && this.rebal9p) {
+    gameMode = 'avalonCustom';
+  }
+
   const objectToStore = {
     timeGameStarted: this.startGameTime,
     timeAssassinationStarted: this.startAssassinationTime,
@@ -1326,8 +1340,9 @@ Game.prototype.finishGame = function (toBeWinner) {
     resistanceTeam: this.resistanceUsernames,
     numberOfPlayers: this.playersInGame.length,
 
-    gameMode: this.gameMode,
+    gameMode,
     botUsernames,
+    rebal9p: this.rebal9p,
 
     playerUsernamesOrdered: getUsernamesOfPlayersInGame(this),
     playerUsernamesOrderedReversed: gameReverseArray(
@@ -1901,6 +1916,16 @@ Game.prototype.updateMuteSpectators = function (muteSpectators: boolean) {
   );
 };
 
+Game.prototype.updateRebal9p = function (rebal9p: boolean) {
+  this.rebal9p = rebal9p;
+
+  this.sendText(
+    this.allSockets,
+    `Rebalanced 9p option set to ${rebal9p}.`,
+    'server-text'
+  );
+};
+
 /*
 ELO RATING CALCULATION:
 
diff --git a/src/gameplay/gameWrapper.js b/src/gameplay/gameWrapper.js
index aa9849beb..dfc12ffae 100644
--- a/src/gameplay/gameWrapper.js
+++ b/src/gameplay/gameWrapper.js
@@ -11,6 +11,7 @@ function GameWrapper(
   muteSpectators_,
   gameMode_,
   ranked_,
+  rebal9p_,
   callback_,
 ) {
   // Get all the game properties
@@ -24,6 +25,7 @@ function GameWrapper(
     muteSpectators_,
     gameMode_,
     ranked_,
+    rebal9p_,
     callback_,
   );
 }
diff --git a/src/gameplay/playersReadyNotReady.js b/src/gameplay/playersReadyNotReady.js
index b09ee9e32..3a6c96ac3 100644
--- a/src/gameplay/playersReadyNotReady.js
+++ b/src/gameplay/playersReadyNotReady.js
@@ -144,6 +144,7 @@ playersReadyNotReady.prototype.hostTryStartGame = function (options, gameMode) {
 
     rolesInStr += `<br>Ranked: ${this.ranked}`;
     rolesInStr += `<br>Mute Spectators: ${this.muteSpectators}`;
+    rolesInStr += `<br>Rebalanced 9p: ${this.rebal9p}`;
 
     for (let i = 0; i < this.socketsOfPlayers.length; i++) {
       this.socketsOfPlayers[i].emit('game-starting', rolesInStr, gameMode);
diff --git a/src/models/gameRecord.js b/src/models/gameRecord.js
index 788b36326..3d821da21 100644
--- a/src/models/gameRecord.js
+++ b/src/models/gameRecord.js
@@ -9,6 +9,7 @@ const gameRecordSchema = new mongoose.Schema({
   spyTeam: [String],
   resistanceTeam: [String],
 
+  rebal9p: Boolean,
   gameMode: String,
   botUsernames: [String],
 
diff --git a/src/sockets/sockets.ts b/src/sockets/sockets.ts
index 6e2e330b7..ddcb81300 100644
--- a/src/sockets/sockets.ts
+++ b/src/sockets/sockets.ts
@@ -387,6 +387,7 @@ export let modCommands = {
         dataObj.gameMode,
         dataObj.muteSpectators,
         false,
+        false,
         socketCallback,
       );
       const privateStr = dataObj.newRoomPassword === '' ? '' : 'private ';
@@ -2126,6 +2127,7 @@ export const server = function (io: SocketServer): void {
     socket.on('update-room-game-mode', updateRoomGameMode);
     socket.on('update-room-ranked', updateRoomRanked);
     socket.on('update-room-muteSpectators', updateRoomMuteSpectators);
+    socket.on('update-room-rebal9p', updateRoomRebal9p);
 
     //* ***********************
     // game data stuff
@@ -2762,6 +2764,7 @@ function newRoom(dataObj) {
       dataObj.gameMode,
       dataObj.muteSpectators,
       rankedRoom,
+      dataObj.rebal9p,
       socketCallback,
     );
     const privateStr = !privateRoom ? '' : 'private ';
@@ -2984,6 +2987,12 @@ function updateRoomMuteSpectators(muteSpectators) {
   }
 }
 
+function updateRoomRebal9p(rebal9p) {
+  if (rooms[this.request.user.inRoomId]) {
+    rooms[this.request.user.inRoomId].updateRebal9p(rebal9p);
+  }
+}
+
 function updateRoomMaxPlayers(number) {
   if (rooms[this.request.user.inRoomId]) {
     rooms[this.request.user.inRoomId].updateMaxNumPlayers(this, number);
diff --git a/src/views/lobby.ejs b/src/views/lobby.ejs
index 1d0f4876e..69757d28f 100644
--- a/src/views/lobby.ejs
+++ b/src/views/lobby.ejs
@@ -970,6 +970,11 @@
 
         <label>Mute spectators for table:</label>
         <input type="checkbox" name="muteSpectators" class="muteSpectators" />
+
+        <br />
+
+        <label>Rebalanced 9P (4 spies):</label>
+        <input type="checkbox" name="rebal9p" class="rebal9p" />
       </div>
       <div class="modal-footer">
         <button type="button" class="btn btn-default" data-dismiss="modal">
@@ -1210,6 +1215,11 @@
 
         <label>Mute spectators for table:</label>
         <input type="checkbox" name="muteSpectators" class="muteSpectators" />
+
+        <br />
+
+        <label>Rebalanced 9p (4 spies):</label>
+        <input type="checkbox" name="rebal9p" class="rebal9p" />
       </div>
       <div class="modal-footer">
         <button type="button" class="btn btn-danger" data-dismiss="modal">