diff --git a/SabreTools.Library/DatFiles/DatFile.cs b/SabreTools.Library/DatFiles/DatFile.cs
index 2b1d88af..cc21f4ab 100644
--- a/SabreTools.Library/DatFiles/DatFile.cs
+++ b/SabreTools.Library/DatFiles/DatFile.cs
@@ -326,6 +326,14 @@ namespace SabreTools.Library.DatFiles
                 DiffAgainst(inputFileNames, outDir, inplace);
             }
 
+            // If we are in game diffing mode
+            else if (updateMode.HasFlag(UpdateMode.DiffGame))
+            {
+                // Populate the combined data
+                PopulateUserData(baseFileNames, filter);
+                DiffGame(inputFileNames, outDir, inplace, filter);
+            }
+
             // If we have one of the base replacement modes
             else if (updateMode.HasFlag(UpdateMode.BaseReplace)
                 || updateMode.HasFlag(UpdateMode.ReverseBaseReplace))
@@ -406,6 +414,19 @@ namespace SabreTools.Library.DatFiles
             DiffNoCascade(paths, outDir, diff);
         }
 
+        /// <summary>
+        /// Output games that contain different items (by name)
+        /// </summary>
+        /// <param name="inputs">Names of the input files</param>
+        /// <param name="outDir">Optional param for output directory</param>
+        /// <param name="inplace">True if the output files should overwrite their inputs, false otherwise</param>
+        /// <param name="filter">Filter object to be passed to the DatItem level</param>
+        public void DiffGame(List<string> inputs, string outDir, bool inplace, Filter filter)
+        {
+            List<ParentablePath> paths = inputs.Select(i => new ParentablePath(i)).ToList();
+            DiffGame(paths, outDir, inplace, filter);
+        }
+
         /// <summary>
         /// Output user defined merge
         /// </summary>
@@ -1226,6 +1247,70 @@ namespace SabreTools.Library.DatFiles
             watch.Stop();
         }
 
+        /// <summary>
+        /// Replace item values from the base set represented by the current DAT
+        /// </summary>
+        /// <param name="inputs">Names of the input files</param>
+        /// <param name="outDir">Optional param for output directory</param>
+        /// <param name="inplace">True if the output files should overwrite their inputs, false otherwise</param>
+        /// <param name="filter">Filter object to be passed to the DatItem level</param>
+        /// <remarks>TODO: Can this be wrapped into DiffAgainst?</remarks>
+        internal void DiffGame(List<ParentablePath> inputs, string outDir, bool inplace, Filter filter)
+        {
+            // Order the current DAT by game first
+            Items.BucketBy(BucketedBy.Game, DedupeType.None);
+
+            // We want to try to replace each item in each input DAT from the base
+            foreach (ParentablePath path in inputs)
+            {
+                Globals.Logger.User($"Comparing items in '{path.CurrentPath}' to the base DAT");
+
+                // First we parse in the DAT internally
+                DatFile intDat = Create(Header.CloneFiltering());
+                intDat.Parse(path, 1, keep: true);
+                filter.FilterDatFile(intDat, false /* useTags */);
+                intDat.Items.BucketBy(BucketedBy.Game, DedupeType.None);
+
+                // TODO: Do we need to include items in base NOT in compare?
+                List<string> games = intDat.Items.Keys.ToList();
+                foreach (string game in games)
+                {
+                    // If the base DAT doesn't contain the key, keep it
+                    if (!Items.ContainsKey(game))
+                        continue;
+
+                    // If the number of items is different, then keep it
+                    if (Items[game].Count != intDat.Items[game].Count)
+                        continue;
+
+                    // Otherwise, compare by name and hash the remaining files
+                    bool exactMatch = true;
+                    foreach (DatItem item in intDat.Items[game])
+                    {
+                        // TODO: Make this granular to name as well
+                        if (!Items[game].Contains(item))
+                        {
+                            exactMatch = false;
+                            break;
+                        }
+                    }
+
+                    // If we have an exact match, remove the game
+                    if (exactMatch)
+                        intDat.Items.Remove(game);
+                }
+
+                // Determine the output path for the DAT
+                string interOutDir = path.GetOutputPath(outDir, inplace);
+
+                // Once we're done, try writing out
+                intDat.Write(interOutDir, overwrite: inplace);
+
+                // Due to possible memory requirements, we force a garbage collection
+                GC.Collect();
+            }
+        }
+
         /// <summary>
         /// Output user defined merge
         /// </summary>
diff --git a/SabreTools.Library/Data/Flags.cs b/SabreTools.Library/Data/Flags.cs
index 3684ad5b..4942b59d 100644
--- a/SabreTools.Library/Data/Flags.cs
+++ b/SabreTools.Library/Data/Flags.cs
@@ -257,11 +257,12 @@ namespace SabreTools.Library.Data
 
         // Base diffs
         DiffAgainst = 1 << 5,
+        DiffGame = 1 << 6,
 
         // Special update modes
-        Merge = 1 << 6,
-        BaseReplace = 1 << 7,
-        ReverseBaseReplace = 1 << 8,
+        Merge = 1 << 7,
+        BaseReplace = 1 << 8,
+        ReverseBaseReplace = 1 << 9,
 
         // Combinations
         AllDiffs = DiffDupesOnly | DiffNoDupesOnly | DiffIndividualsOnly,
diff --git a/SabreTools.Library/README.1ST b/SabreTools.Library/README.1ST
index 118d2bd6..de42a662 100644
--- a/SabreTools.Library/README.1ST
+++ b/SabreTools.Library/README.1ST
@@ -1205,6 +1205,16 @@ Options:
 			  Add a DAT or folder of DATs to the base set to be used for all
 			  operations. Multiple instances of this flag are allowed.
 
+	  -dga, --diff-game		Diff all inputs by game against a set of base DATs
+		  This flag will enable a special type of diffing in which a set of base
+		  DATs are used as a comparison point for each of the input DATs by game.
+		  This allows users to get a slightly different output to cascaded
+		  diffing, which may be more useful in some cases.
+
+		  -bd=, --base-dat=		   Add a base DAT for processing
+			  Add a DAT or folder of DATs to the base set to be used for all
+			  operations. Multiple instances of this flag are allowed.
+
 	  -br, --base-replace		 Replace from base DATs in order
 		  By default, no item names are changed except when there is a merge
 		  occurring. This flag enables users to define a DAT or set of base
diff --git a/SabreTools/Features/BaseFeature.cs b/SabreTools/Features/BaseFeature.cs
index 31fb5906..d1808f07 100644
--- a/SabreTools/Features/BaseFeature.cs
+++ b/SabreTools/Features/BaseFeature.cs
@@ -336,6 +336,20 @@ namespace SabreTools.Features
             }
         }
 
+        internal const string DiffGameValue = "diff-game";
+        internal static Feature DiffGameFlag
+        {
+            get
+            {
+                return new Feature(
+                    DiffAgainstValue,
+                    new List<string>() { "-dga", "--diff-game" },
+                    "Diff all inputs by game against a set of base DATs",
+                    FeatureType.Flag,
+                    "This flag will enable a special type of diffing in which a set of base DATs are used as a comparison point for each of the input DATs by game. This allows users to get a slightly different output to cascaded diffing, which may be more useful in some cases.");
+            }
+        }
+
         internal const string DiffIndividualsValue = "diff-individuals";
         internal static Feature DiffIndividualsFlag
         {
@@ -2489,6 +2503,9 @@ Some special strings that can be used:
             if (GetBoolean(features, DiffDuplicatesValue))
                 updateMode |= UpdateMode.DiffDupesOnly;
 
+            if (GetBoolean(features, DiffGameValue))
+                updateMode |= UpdateMode.DiffGame;
+
             if (GetBoolean(features, DiffIndividualsValue))
                 updateMode |= UpdateMode.DiffIndividualsOnly;
 
diff --git a/SabreTools/Features/Update.cs b/SabreTools/Features/Update.cs
index bc286ef1..e63234f1 100644
--- a/SabreTools/Features/Update.cs
+++ b/SabreTools/Features/Update.cs
@@ -56,6 +56,8 @@ namespace SabreTools.Features
             this[DiffNoDuplicatesFlag].AddFeature(NoAutomaticDateFlag);
             AddFeature(DiffAgainstFlag);
             this[DiffAgainstFlag].AddFeature(BaseDatListInput);
+            AddFeature(DiffGameFlag);
+            this[DiffGameFlag].AddFeature(BaseDatListInput);
             AddFeature(BaseReplaceFlag);
             this[BaseReplaceFlag].AddFeature(BaseDatListInput);
             this[BaseReplaceFlag].AddFeature(UpdateFieldListInput);