diff --git a/DATabase/DATabase.cs b/DATabase/DATabase.cs
index 89fbf3ef..48f7b253 100644
--- a/DATabase/DATabase.cs
+++ b/DATabase/DATabase.cs
@@ -51,6 +51,7 @@ namespace SabreTools
 
 			// Set all default values
 			bool help = false,
+				ad = false,
 				add = false,
 				bare = false,
 				convertMiss = false,
@@ -109,6 +110,10 @@ namespace SabreTools
 					case "--add":
 						add = true;
 						break;
+					case "-ad":
+					case "--all-diff":
+						ad = true;
+						break;
 					case "-b":
 					case "--bare":
 						bare = true;
@@ -435,7 +440,7 @@ namespace SabreTools
 			// Merge, diff, and dedupe at least 2 DATs
 			else if (merge)
 			{
-				InitMergeDiff(inputs, name, desc, cat, version, author, diff, dedup, bare, forceunpack, old);
+				InitMergeDiff(inputs, name, desc, cat, version, author, ad, diff, dedup, bare, forceunpack, old);
 			}
 
 			logger.Close();
@@ -854,7 +859,7 @@ Make a selection:
 		private static void MergeDiffMenu()
 		{
 			string selection = "", input = "", name = "", desc = "", cat = "", version = "", author = "";
-			bool dedup = false, diff = false, bare = false, forceunpack = false, old = false;
+			bool ad = false, dedup = false, diff = false, bare = false, forceunpack = false, old = false;
 			while (selection.ToLowerInvariant() != "b")
 			{
 				Console.Clear();
@@ -869,12 +874,13 @@ Make a selection:
     4) Category" + (cat != "" ? ":\t" + cat : "") + @"
     5) Version" + (version != "" ? ":\t" + version : "") + @"
     6) Author" + (author != "" ? ":\t" + author : "") + @"
-    7) " + (dedup ? "Don't dedup files in output" : "Dedup files in output") + @"
-    8) " + (diff ? "Only merge the input files" : "Diff the input files") + @"
-    9) " + (bare ? "Don't append the date to the name" : "Append the date to the name") + @"
-    10) " + (forceunpack ? "Remove 'forcepacking=\"unzip\"' from output" : "Add 'forcepacking=\"unzip\"' to output") + @"
-    11) " + (old ? "Enable XML output" : "Enable ClrMamePro output") + @"
-    12) Merge the DATs
+    7) " + (ad ? "Only output normal diff" : "Output all diff variants") + @"
+    8) " + (dedup ? "Don't dedup files in output" : "Dedup files in output") + @"
+    9) " + (diff ? "Only merge the input files" : "Diff the input files") + @"
+    10) " + (bare ? "Don't append the date to the name" : "Append the date to the name") + @"
+    11) " + (forceunpack ? "Remove 'forcepacking=\"unzip\"' from output" : "Add 'forcepacking=\"unzip\"' to output") + @"
+    12) " + (old ? "Enable XML output" : "Enable ClrMamePro output") + @"
+    13) Merge the DATs
     B) Go back to the previous menu
 ");
 				Console.Write("Enter selection: ");
@@ -912,24 +918,27 @@ Make a selection:
 						author = Console.ReadLine();
 						break;
 					case "7":
-						dedup = !dedup;
+						ad = !ad;
 						break;
 					case "8":
-						diff = !diff;
+						dedup = !dedup;
 						break;
 					case "9":
-						bare = !bare;
+						diff = !diff;
 						break;
 					case "10":
-						forceunpack = !forceunpack;
+						bare = !bare;
 						break;
 					case "11":
-						old = !old;
+						forceunpack = !forceunpack;
 						break;
 					case "12":
+						old = !old;
+						break;
+					case "13":
 						Console.Clear();
 						List<string> inputs = new List<string>(input.Split(';'));
-						InitMergeDiff(inputs, name, desc, cat, version, author, diff, dedup, bare, forceunpack, old);
+						InitMergeDiff(inputs, name, desc, cat, version, author, ad, diff, dedup, bare, forceunpack, old);
 						Console.Write("\nPress any key to continue...");
 						Console.ReadKey();
 						break;
@@ -1364,7 +1373,7 @@ Make a selection:
 		/// <param name="bare">True if the date should be omitted from the DAT, false otherwise</param>
 		/// <param name="forceunpack">True if the forcepacking="unzip" tag is to be added, false otherwise</param>
 		/// <param name="old">True if a old-style DAT should be output, false otherwise</param>
-		private static void InitMergeDiff(List<string> inputs, string name, string desc, string cat, string version, string author, bool diff, bool dedup, bool bare, bool forceunpack, bool old)
+		private static void InitMergeDiff(List<string> inputs, string name, string desc, string cat, string version, string author, bool ad, bool diff, bool dedup, bool bare, bool forceunpack, bool old)
 		{
 			// Make sure there are no folders in inputs
 			List<string> newInputs = new List<string>();
@@ -1383,7 +1392,7 @@ Make a selection:
 				}
 			}
 
-			MergeDiff md = new MergeDiff(newInputs, name, desc, cat, version, author, diff, dedup, bare, forceunpack, old, logger);
+			MergeDiff md = new MergeDiff(newInputs, name, desc, cat, version, author, ad, diff, dedup, bare, forceunpack, old, logger);
 			md.Process();
 		}
 
diff --git a/DATabase/MergeDiff.cs b/DATabase/MergeDiff.cs
index a7f72e60..30cf5d50 100644
--- a/DATabase/MergeDiff.cs
+++ b/DATabase/MergeDiff.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 
 using SabreTools.Helper;
 
@@ -11,6 +12,7 @@ namespace SabreTools
 		private List<String> _inputs;
 
 		// User specified flags
+		private bool _ad;
 		private bool _diff;
 		private bool _dedup;
 		private bool _bare;
@@ -37,6 +39,7 @@ namespace SabreTools
 		/// <param name="cat">Category for the DAT</param>
 		/// <param name="version">Version of the DAT</param>
 		/// <param name="author">Author of the DAT</param>
+		/// <param name="ad">True if all diff variants should be outputted, false otherwise</param>
 		/// <param name="diff">True if a DiffDat of all inputs is wanted, false otherwise</param>
 		/// <param name="dedup">True if the outputted file should remove duplicates, false otherwise</param>
 		/// <param name="bare">True if the date should be omitted from the DAT, false otherwise</param>
@@ -44,7 +47,7 @@ namespace SabreTools
 		/// <param name="old">True if a old-style DAT should be output, false otherwise</param>
 		/// <param name="logger">Logger object for console and file output</param>
 		public MergeDiff(List<String> inputs, string name, string desc, string cat, string version, string author,
-			bool diff, bool dedup, bool bare, bool forceunpack, bool old, Logger logger)
+			bool ad, bool diff, bool dedup, bool bare, bool forceunpack, bool old, Logger logger)
 		{
 			_inputs = inputs;
 			_name = name;
@@ -52,6 +55,7 @@ namespace SabreTools
 			_cat = cat;
 			_version = version;
 			_author = author;
+			_ad = ad;
 			_diff = diff;
 			_dedup = dedup;
 			_bare = bare;
@@ -78,6 +82,8 @@ namespace SabreTools
 			}
 
 			List<RomData> A = new List<RomData>();
+			List<RomData> X = new List<RomData>();
+
 			foreach (string input in _inputs)
 			{
 				_logger.Log("Adding DAT: " + input);
@@ -90,6 +96,56 @@ namespace SabreTools
 				{
 					A.AddRange(B);
 				}
+
+				// If we're in all-diff mode, get a master merged DAT to compare against
+				if (_ad)
+				{
+					X.AddRange(B);
+				}
+			}
+
+			// If we're in all diff mode, diff against every DAT and output accordingly
+			if (_ad)
+			{
+				foreach (string input in _inputs)
+				{
+					List<RomData> B = RomManipulation.Parse(input, 0, 0, _logger);
+					List<RomData> C = RomManipulation.DiffOnlyInA(B, X);
+					List<RomData> D = RomManipulation.DiffInAB(B, X);
+
+					if (_dedup)
+					{
+						C = RomManipulation.Merge(C);
+						D = RomManipulation.Merge(D);
+					}
+
+					if (_name == "")
+					{
+						_name = (_diff ? "diffdat" : "mergedat") + (_dedup ? "-merged" : "");
+					}
+					if (_desc == "")
+					{
+						_desc = (_diff ? "diffdat" : "mergedat") + (_dedup ? "-merged" : "");
+						if (!_bare)
+						{
+							_desc += " (" + _date + ")";
+						}
+					}
+					if (_cat == "" && _diff)
+					{
+						_cat = "DiffDAT";
+					}
+					if (_author == "")
+					{
+						_author = "SabreTools";
+					}
+
+					string realname = Path.GetFileNameWithoutExtension(input);
+
+					// Now write the files out
+					Output.WriteToDat(_name + "-" + realname + "-inall", _desc + "-" + realname + "-inall", _version, _date, _cat, _author, _forceunpack, _old, "", C, _logger);
+					Output.WriteToDat(_name + "-" + realname + "-only", _desc + "-" + realname + "-only", _version, _date, _cat, _author, _forceunpack, _old, "", D, _logger);
+				}
 			}
 
 			// If we want a merged list, send it for merging before outputting
diff --git a/SabreHelper/Build.cs b/SabreHelper/Build.cs
index d04f54aa..8378cfdd 100644
--- a/SabreHelper/Build.cs
+++ b/SabreHelper/Build.cs
@@ -118,6 +118,7 @@ Options:
   -lso, --list-sources	List all sources (id <= name)
   -lsy, --list-systems	List all systems (id <= name)
   -m, --merge		Merge two or more DATs
+	-ad, --all-diff	Enable output of all diff variants
 	-di, --diff		Switch to diffdat mode
 	-dd, --dedup		Enable deduping in the created DAT
 	-b, --bare		Don't include date in file name
diff --git a/SabreHelper/RomManipulation.cs b/SabreHelper/RomManipulation.cs
index 8b712132..da2b79a5 100644
--- a/SabreHelper/RomManipulation.cs
+++ b/SabreHelper/RomManipulation.cs
@@ -451,5 +451,35 @@ namespace SabreTools.Helper
 			List<String> CString = AString.Except(BString).Union(BString.Except(AString)).ToList();
 			return Output.StringToRomData(CString);
 		}
+
+		/// <summary>
+		/// Get all RomData objects that are in A but not in B
+		/// </summary>
+		/// <param name="A">First RomData list</param>
+		/// <param name="B">Second RomData list</param>
+		/// <returns>Any rom that's only in the first list</returns>
+		/// <remarks>Adapted from http://stackoverflow.com/questions/5620266/the-opposite-of-intersect</remarks>
+		public static List<RomData> DiffOnlyInA(List<RomData> A, List<RomData> B)
+		{
+			List<String> AString = Output.RomDataToString(A);
+			List<String> BString = Output.RomDataToString(B);
+			List<String> CString = AString.Except(BString).ToList();
+			return Output.StringToRomData(CString);
+		}
+
+		/// <summary>
+		/// Get all RomData objects that are in A and B
+		/// </summary>
+		/// <param name="A">First RomData list</param>
+		/// <param name="B">Second RomData list</param>
+		/// <returns>Any rom that's in both lists</returns>
+		/// <remarks>Adapted from http://stackoverflow.com/questions/5620266/the-opposite-of-intersect</remarks>
+		public static List<RomData> DiffInAB(List<RomData> A, List<RomData> B)
+		{
+			List<String> AString = Output.RomDataToString(A);
+			List<String> BString = Output.RomDataToString(B);
+			List<String> CString = AString.Union(BString).Except(AString.Except(BString).Union(BString.Except(AString))).ToList();
+			return Output.StringToRomData(CString);
+		}
 	}
 }